SlideShare uma empresa Scribd logo
1 de 7
Baixar para ler offline
Journal of Advanced Engineering Research
ISSN: 2393-8447
Volume 2, Issue X, 2015, pp.XX-XX
Research Article 1 www.jaeronline.com
FREE PISTON LINEAR ENGINE [FPLE]- A REVIEW
Shafeequr Rahman S. I1*, Surya Kandhaswamy T2, Dr. P. Gopal3
1Department of Automobile Engineering, Anna University, Tiruchirappalli-620024, India
2Department of Automobile Engineering, Anna University, Tiruchirappalli-620024, India
3Asst. Prof, Department of Automobile Engineering, Anna University, Tiruchirappalli-620024, India
*Corresponding author email: shafeeq16101995@gmail.com , Tel. :8754222018
ABSTRACT
Unlike conventionalinternal combustion engines,a free-piston linear engine has no a crankshaft, and thus the pistons move
freely in the cylinder. This allows a free-piston linear engine to easily adjust the compression ratio and optimize the
combustion process. Free-piston linear engines include two main parts: a free-piston engine and a linear alternator. The
free-piston engine is classified into three main types:single piston,dual piston, and opposed piston.The linear alternator
is generally categorized as flat-type or tubular-type. Free-piston linear engines can operate with multi-fuel and HCCI
combustion because of their variable compression ratios. Furthermore, they are used to generate the electric power applied
in hybrid electric vehicles. To promote understanding of the unique features of free-piston linear engines, this paper
presents a review of their different designs and operating characteristics. We also discuss the varied experimental systems
and applications of free-piston linear engines
Keywords – FPLE, Free piston, Linear engine, FPEG
1. INTRODUCTION
The free-piston linear engine (FPLE) is a linear energy
conversion system, and the term ‘free-piston’ is widely
used to distinguish its linear characteristics from those of
a conventional reciprocating engine. Without the
limitation of the crankshaft mechanism, as known for the
conventional engines, the piston is free to oscillate
between its dead centers.The piston assembly is the only
significant moving component for the FPLEs, and its
movement is determined by the gas and load forces
acting upon it. During the operation of FPLEs,
combustion takes place in the internal combustion
chamber, and the high pressure exhaust gas pushes the
piston assembly backwards. The chemical energy from
the air fuel mixture is then converted to the mechanical
energy of the moving piston assembly. Due to this linear
characteristic, a FPLE requires a linear load to convert
this mechanical energy for the usage of the target
application. As the load is coupled directly to the piston
assembly, the technical requirements for the free-piston
engine loads are high, which are summarized as:
(1) The load must provide satisfactory energy conversion
efficiency to make the overall systemefficient.
(2) The load may be subjected to high velocity
(3) The load may be subjected to high force from the
cylinder gas.
(4) The load device may be subjected to heat transfer
from the engine cylinders
(5) The size, moving mass and load force profile are
feasible to be coupled with the designed FPEs. Reported
load devices for the FPEs include air compressors,
electric generators and hydraulic pumps.In this research,
the FPE is connected with a linear electric generator
(free-piston engine generator, FPEG) and is investigated
with the objective to utilize the configuration within a
hybrid-electric automotive vehicle power system. Since
the FPEG was first proposed, it has attracted interest
from all over the world.
Different research methods and prototype designs
have been reported using the FPLE concept.However, to
date, none of these have been commercially realized in
part due to the challenges of system control. In
conventional engines, the crankshaft mechanism
provides piston motion control, defining both the outer
positions of the piston motion (the dead centers) and the
piston motion profile. Due to the high inertia of the
crankshaft system, the piston motion cannot be
influenced in the timeframe of one cycle. In the free-
piston engine, the piston motion is determined by the
instantaneous sumofthe forces acting on the mover, and
the piston motion is therefore influenced by the progress
of the combustion process.Moreover, the piston motion
profile may be different for different operating
conditions.Variations between consecutive cycles due to
cycle-to-cycle variations in the in-cylinder processes are
Shafeequr Rahman S.I et al., / Journal of Advanced Engineering Research, 2015, x (x), xxx-xxx
Research Article 2 www.jaeronline.com
also possible.Overcome controlling of the FPLE engine
is a challenging task.
2. Classification ofFPLEs
2.1. NUMBER OF STROKES
Similar to traditional internal combustion engines,
FPLEs are classified into four-stroke and two-stroke
engines. The strokes of a four-stroke FPLE are intake,
compression, combustion, and exhaust. In a traditional
internal combustion engine with a crankshaft
mechanism, the four strokes happen in two revolutions
of the crankshaft, and the combustion stroke is called the
power stroke. For FPLEs, the four strokes occur in the
linear motion of the piston, and the intake and exhaust
valves are controlled by an electronic system. Xu and
Chang [31] studied the motion control of a four stroke
FPLE developed for electric power generation. The
piston strokes combined with the open/close timing of
the intake and exhaust valves were electronically
controlled. Even though the four-stroke principle can be
applied to FPLEs, it presents greatertechnicalchallenges
for motion control than two-stroke engines.
The technical challenges for motion control of the
four-stroke FPLE include the complex control of the
opening/closing times of the intake and exhaust valves
vis-à-vis the linear motion of the piston. The
opening/closing times of the intake and exhaust valves
must be controlled correctly to prevent a collision
between them and the piston crown. Therefore, four-
stroke FPLEs have been investigated less than two-
stroke FPLEs, which simplify the engine structure and
improve motion control. Jia et al [32]. simulated the
piston dynamics and thermodynamics of a two- or four-
stroke FPLE. For the two-stroke cycle,
the linear generator was used only as a generator,
whereas it functioned as both a motor and a generator in
the four-stroke cycle. They found that the piston speed
during the expansion process ofthe four-stroke cycle was
higher than that ofthe two-stroke cycle. However, for the
non-power strokes of the four-stroke cycle, the piston
speed was much lower because of the brake force of the
motor, as shown in Fig. 1. They also showed that the heat
release process was more aligned with a constant volume
process when the FPLE operated in two-stroke mode,
and the peak cylinder pressure of four-stroke cycle was
higher than that of the two-stroke cycle, as shown in Fig.
2. This can be explained by increasing of piston
displacement in the four-stroke cycle. As can be seen in
the displacement of the piston in the four-stroke cycle
was significantly longer than that in the two-stroke cycle
because in the four-stroke cycle, piston movement could
be controlled by optimizing the motor forces. To ensure
stable and smooth engine operation using a four-stroke
cycle, the authors proposed a more complex and robust
control system. Their simulation results also indicated
that the indicated power and electric power of the two-
stroke cycle were much higher than those of the four-
stroke cycle with the same throttle opening.
Because the electric power generated in the four-
stroke cycle was used to compensate for the overall
power consumption during the motoring processes. The
strokes of the most typical two-stroke FPLE are
scavenging compression and combustion–expansion.
The scavenging process occurs in different ways
depending on the engine type. Goldsborough and
Blarigan [33] presented an optimal study for the
scavenging system of a two-stroke FPLE. They
investigated a wide range of design options, including
loop, hybrid-loop, and uniflow scavenging methods.The
uniflow method uses the exhaust valve to liberate exhaust
gas during the scavenging process.Locating the exhaust
valves in the cylinder head ensures better flushing at the
top of the combustion chamber, but increases the
mechanical complexity of the engine because the valves
must be actuated. Two stroke FPLEs using the uniflow
scavenging method are also found in other studies.
2.2. PISTON CONFIGURATION
In general, FPLEs can be classified into three piston
types: single piston, double piston (dual piston and
opposed piston), and four pistons (dual piston, opposed
piston, and complex piston configuration), Of those, the
single-piston engine has a simple design with higher
controllability than the other FPLEs; however, the
dynamic balance is not good because it has only one
piston.Mikalsen and Roskilly [16] proposed a prototype
of a single-piston FPLE for electric power generation in
large scale systems. Their engine includes a combustion
cylinder, a bounce chamber cylinder, and a linear electric
machine.
In this engine, the amount of air contained in the
bounce chamber is varied by controlvalves to change the
force coming from the bounce chamber. Tian et al.
replaced the bounce chamber with a rebound spring. This
allowed a simpler design, compared with the design of
Mikalsen and Roskilly [17] So far, the single-piston
FPLE is the closest to a commercial system because it
offers the simplest configuration and high controllability.
Kosaka et al [40]. developed a prototype single piston
FPLE using a cooling and lubricating systemalong with
control system logic, which contributed significantly to
commercialization of an FPLE. Their single piston FPLE
used a cooling oil passage and a water-cooled cylinder
head. A perfectly balanced design is the main advantage
of opposed piston configurations,but those designsmake
engines complicated. Pontus Ostenberg [5] presented an
early opposed-piston FPLE in 1943, Therein, a denotes a
free-piston engine with opposed pistons (piston 2 and
Shafeequr Rahman S.I et al., / Journal of Advanced Engineering Research, 2015, x (x), xxx-xxx
Research Article 3 www.jaeronline.com
piston 2a), and B denotes a single-phase linear alternator.
In Pontus Ostenberg’s [5] engine.
3.2. Combustion characteristics
3.2.1. Spark ignition combustion
Similar to a traditional internal combustion engine, an
SI FPLE uses sparkplugs installed in the cylinder head
to ignite the air/fuel mixture in the cylinder when
generating power. To investigate the combustion
characteristics of an SI FPLE, many studies have been
conducted,including both simulations and experiments.
Mikalsen and Roskilly [15] compared the performance
of an SI-FPLE with that of a conventionalengine using
a computational fluid dynamics (CFD) simulation
model. They showed that the FPLE obtained a slight
efficiency advantage overthe conventionalengine at
low speeds,but that the efficiency of the free-piston
engine dropped as the speed increased because the
effects of volume change during combustion were
greater at higher speeds.
They also found that the free-piston engine is lower
than that of the traditional hydrogen engine, this engine
had a slight benefit in NO emissions when compared
with the conventionalengine, Because the shortertime
spent around TDC and the faster expansion in the free
piston engine influenced the NOx levels Yuan et al also
showed a lower level of NO emissions in a free-piston
hydrogen engine compared with a traditional hydrogen
engine. Because the mean in-cylinder gas temperature
of the free-piston hydrogen x
3.2.2. Compression ignition combustion
CI in an internal combustion engine is a process in which
the necessary high temperature is produced by
compressing the air in the cylinder before the fuel is
injected into the combustion chamber. For FPLEs, CI is
generally investigated with diesel fuel Mao et al.
presented a simulation study of a free-piston diesel
engine using a zero-dimensional numerical simulation
combined with a CFD model (AVL-FIRE) to simulate
the gas exchange and combustion processes. They used
the two-stage Wiebe function to model the combustion
process in time, one stage for premixed and one stage for
diffusive combustion. They derived the ignition delay
and combustion duration from the CFD calculation for
diesel FPLE combustion.
In another simulation study, Mikalsen and Roskilly
[11] investigated the combustion process ofa free-piston
diesel engine using a CFD model (Open FOAM) and
compared the results with those from a conventional
engine.They found that the free-piston diesel engine had
a higher heat release rate from the pre-mixed combustion
phase because of an increased ignition delay, compared
with the conventional engine. In another simulation
study conducted by Mikalsen and Roskilly [15], they
compared the simulation results of a two-stroke free
piston CI engine with those from a respective
conventional CI engine. Therein, a single-zone model
was used to simulate combustion, while in-cylinder heat
transfer was modeled according to Hohenberg. They
found that the indicated efficiency of the free-piston
engine was higher than that of the conventional engine
because of reduced heat transfer losses and lower
frictional losses. Both peak gas temperature and
temperature levels during expansion were lower in the
free-piston engine, and that resulted in lower heat
transfer losses.
Yuan et al investigated the combustion characteristics
of a free-piston diesel engine coupling with dynamic and
scavenging models. Their coupled model used an
empirical heat release model of the Wiebe function to
calculate the piston motion profile based on the initial
boundary conditions. They used a scavenging CFD
model to calculate the gas exchange performances
according to the calculated piston motion. They then
imported the calculated scavenging results and piston
motion into a combustion CFD model to calculate the
combustion performances and fed those results with the
gas exchange results back to the dynamic model to
calculate the next iteration.
Afterward, they’re established the scavenging CFD
model and calculated a new using the updated results
from piston motion and combustion, repeating the
procedure until they met the iterative convergence
conditions. Their simulation results showed benefits for
reducing temperature dependent emissions (NO) because
the in-cylinder average gas temperature ofthe free-piston
engine was generally lower than that of the traditional
engine. This is also similar to the results obtained by
Mikalsen and Roskilly [11] However, Chenheng Yuan
found that a free-piston engine had no advantage in
particulate emissions when compared with a traditional
crank engine, Shoukry et al. presented a numerical
simulation for a parametric study of a two-stroke direct-
injection linear engine fueled with diesel. They
investigated the effects of parameters such as load
constant, reciprocating mass, injection timing, and
combustion duration on the dynamic and combustion
characteristics of an FPLE, defining injection timing as
piston position before the maximum possible stroke.
To simulate the combustion process, they used the
Wiebe function converted to time and calculated the heat
transfer based on the Woschni model. Their simulation
results showed that the increased reciprocating mass
increased the piston stroke and peak in-cylinder
combustion pressure by increasing the inertial force. The
change of injection timing also contributed to increasing
the peak in-cylinder combustion pressure.Adjusting the
injection timing closer to the maximum stroke led to
higher in-cylinder combustion pressure because of
Shafeequr Rahman S.I et al., / Journal of Advanced Engineering Research, 2015, x (x), xxx-xxx
Research Article 4 www.jaeronline.com
moving the combustion event toward that of the ideal
Otto case.
3.5.2. Homogenous charge compression ignition
Homogenous charge compression ignition (HCCI)
engines compress a premixed charge until it self-ignites,
resulting in very rapid combustion but with poor control
of ignition timing. The free-piston engine is well suited
for this since the requirements for accurate ignition
timing control are lower than in conventional engines.
Potential advantages of HCCI include high efficiencies
due to close to constant volume combustion and the
possibility to burn lean mixtures to reduce gas
temperatures and thereby some types of emissions.
HCCI operation of free-piston engines has been
attempted by among others Aichlmayr and van
Blarigan[48]. A quasi-HCCI approach is mentioned by
Hibi and Ito. Diesel fuel is injected very early in the
compression process but after the intake and exhaust
ports have closed. The fuel does not ignite at injection
because the temperature
4.2. Applications ofFPLE
FPLEs are used to convert chemical energy stored in fuel
into electrical energy. They have been investigated and
developed by scientists and researchers around the
world. The high efficiency of a linear alternator
combined with the simple structures of a free-piston
engine are prompting researchers to further develop
FPLEs for hybrid electric vehicles (HEVs). A group of
authors from General Motors and West Virginia
University provided an integrated design methodology to
select a free-piston engine and linear alternator
combination for use as an HEV auxiliary power unit.
They developed integrated models of the engine and
linear alternator and simulated the electric power output
while varying systemparameters. They also presented an
optimization method for selecting the design that best
met output voltage and power requirements.
Goertz and Peng[13] reviewed feasible hybrid
powertrain concepts, evaluating them based on
additional weight, power per size, fuel efficiency,
reliability, local emissions, production costs, comfort,
safety, and development risk. They found that a free-
piston engine coupled with a linear alternator and battery
was the most promising candidate for a high-efficiency
hybrid vehicle. In a simulation study, Huang developed
an opposed-piston FPLE for an HEV. The simulation
results showed that the newly designed FPLE was
feasible and could obtain a 15 kW average electric power
output with a generating efficiency of 42.5%.
Carter and Wechner[14] designed an FPLE to meet
the highest levels of fuel efficiency and exhaust
emissions performance in a compact size for use in
HEVs. Their FPLE was a combination of a free-piston
engine and an integral generatorand included an integral
compressor and a passive intake valve in the head of the
piston, which eliminated common FPLE problems such
as piston ring wear and the need for an external
compressor, and allowed a significant increase in power
density.Cosic et al. compared the totalefficiency of a 12-
ton truck HEV using a conventional combustion engine
and an FPLE. They found that replacing a conventional
combustion engine with an FPLE increased the total
efficiency of the system by 25%. Hansson et al
investigated the performance gain achieved by using an
FPLE in a medium-sized HEV, compared with a
conventional diesel-generator, and found a potential
decrease in fuel consumption of up to 19% when using
the equivalent consumption minimization strategy
(ECMS),
A group of researchers at Toyota Central R&D Labs
Inc. is developing a prototype 10 kW FPLE for electric
drive vehicles with a thin and compact design, high
efficiency, and high fuel flexibility. This prototype
includes a two stroke combustion chamber, a linear
alternator, and a gas spring chamber. Its main feature is
a stepped piston shape that Toyota calls a ‘‘W-shape”
that has advantages such as decreased heat loss from the
gas spring chamber, a hollow structure to ensure piston
cooling, improved generating efficiency because of a
small clearance between the magnet and the coil, and a
heated magnet to prevented degaussing.
5. CONCLUSION
In this paper, we have reviewed and summarized the
literature on FPLEs with varied designs and operating
features. For piston stroke type, two-stroke FPLEs are
most-commonly investigated and developed because of
their advantages in structure and control. Published
results show that dual-piston FPLEs have a higher
power/weight ratio than other piston arrangements.
However, the combustion process occurs alternately in
each cylinder in a dual-piston engine, which leads to
varied combustion pressure at each cylinder and engine
cycle.
Meanwhile, single-piston FPLEs have a simple
design with higher controllability than the other FPLEs;
however, the dynamic balance is not good because they
have only one piston. Unlike single-piston FPLEs, a
perfectly balanced design is the main advantage of
opposed-piston FPLEs, but those designs make engines
complicated. Besides description of various piston types,
we also described different linear alternator designs for
FPLEs. Namely, we classified linear alternators into
three main groups, including linear alternator shapes
(flat-type and tubular-type linear alternators), phase
structure (single-phase and three-phase linear
alternators), and arrangements of magnets (moving-
magnet, moving-iron, and moving-coil linear
alternators). In a simulation study, flat-type linear
alternator is considered to be better than tubular one in
efficiency, specific power, output voltage and current;
Shafeequr Rahman S.I et al., / Journal of Advanced Engineering Research, 2015, x (x), xxx-xxx
Research Article 5 www.jaeronline.com
however, it needs to be further examined by both
simulation and experiment. For phase structure, much
research has shown that three-phase linear alternators are
appropriate for high-power FPLEs, whereas single-phase
linear alternators are suitable for small power FPLEs. In
addition to the designed features, we classified FPLEs by
their operating characteristics, such as piston dynamics,
combustion, and electric power generation
characteristics.
For piston dynamics, FPLEs decrease heat transfer
loss in the cylinder by increasing piston acceleration,
compared with conventional engines. The
implementation of springs in FPLEs shows benefits for
increasing piston velocity and engine performance. In
addition to benefit of piston dynamics, published results
showthat the thermal efficiency of FPLEs is higher than
that of conventional engines. Furthermore, the
simulation results of FPLEs show benefits for reducing
temperature-dependent emissions (NO) because the in
cylinder gas temperature of FPLEs is generally lower
than that of conventional engines. X The variable
compression ratio in FPLEs is a great benefit for
combustion. By changing the compression ratio, FPLEs
can optimize the combustion process and operate with
various kinds of fuels and HCCI combustion.
To obtain successful HCCI combustion in a free-
piston engine, simulation studies have utilized the
transition from SI to HCCI combustion. Published results
show that the engine performance in HCCI combustion
is higher than in SI combustion, while the in-cylinder
peak temperature in HCCI combustion is much lower
than that in SI combustion, which results in decreasing
NO emissions. A free-piston engine can not only be
operated as a conventional xinternal combustion engine.
It can also be integrated with a linear alternator to
generate electric power. The electric power can be
optimized by adjusting parameters such as piston
assembly mass, ignition timing, equivalence ratio,
electrical resistance, and air gap. Much research has
shown that a linear alternator with a high efficiency
power source is an excellent power-unit candidate for
HEVs. With the potential offered by high-efficiency
linear alternatorsin FPLEs, we expect integrated systems
to be further developed applied in the near future
ACKNOWLEDGEMENTS
This work was supported by Mr. Vinoth. The authors
are grateful to him.
REFERENCE
[1] Wakabayashi R, Takiguchi M, Shimada T, Mizuno
Y, Yamauchi T. The effects of crank ratio and crankshaft
offset on piston friction losses.SAE paper2003-010983;
2003.
[2] Pescara RP. Motor compressor apparatus. US patent
no. 1,657,641; 1928.
[3] Farmer HO. Free piston compressor engines. Proc
Inst Mech Eng
1947; 156:253–71.
[4] Pescara RP. Motorcompressorofthe free piston type.
US patent no. 2,241,957;
1941.
[5] Ostenberg P. Electric generator. US patent 2362151
A; 1944.
[6] Hew WP, Jamaludin J, Tadjuddin M, Nor KM.
Fabrication and testing of a linear
electric generator for use with a free-piston engine. In:
National power and energy conference proceeding.
[7] Wang J, West M, Howe D, Parra H, Arshad W.
Design and experimental verification of a linear
permanent magnet generator for a free-piston energy
converter. IEEE Trans Energy Convers 2007; 22:2.
[8] Li W,Chau KT. A linear magnetic-geared free-piston
generator for range extended
electric vehicles. J Asian Electric Vehicles 2010; 8:1.
[9] Ding H, Yu X, Li J. Permanent magnetic model
design and characteristic
analysis of the short-stroke free piston alternator. SAE
Int J Fuels Lubr 2012.
2012-01-1610.
[10] Xu Z, Chang S. Improved moving coil electric
machine for internal combustion
linear generator. IEEE Trans Energy Convers 2010;
25:2.
[11] Mikalsen R, Roskilly AP. A review of free-piston
engine history and application.
Appl Therm Eng 2007; 27:2339–52.
[12] Cawthorne W, Famouri P, Clark N. Integrated
design of linear alternator/engine
systemfor HEV auxiliary power unit. In: Electric
machines and drives
conference
[13] Goertz M, Peng L. Free piston engine its application
and optimization. SAE paper 2000-01-0996; 2000.
[14] Carter D, WechnerE. The free piston power pack:
sustainable power for hybrid
electric vehicles. SAE paper 2003-01-3277; 2003.
[15] Mikalsen R, Jones E, Roskilly AP. Predictive
piston motion control in a free piston
internal combustion engine. Appl Energy 2010;
87:1722–8.
[16] Mikalsen R, Roskilly AP. The control of a free-
piston engine generator. Part 1:
fundamental analysis. Appl Energy 2010; 87:1273–80.
Shafeequr Rahman S.I et al., / Journal of Advanced Engineering Research, 2015, x (x), xxx-xxx
Research Article 6 www.jaeronline.com
[17] Mikalsen R, Roskilly AP. The control of a free-
piston engine generator. Part 2: engine dynamics and
piston motion control. Appl Energy 2010; 87:1281–7.
[18] Robinson MC, Clark N. Fundamental analysis of
spring-varied, free piston Otto engine device. SAE Int J
Eng 2014. 2014-01-1099.
[19] Kim J, Bae C, Kim G. Simulation on the effect of
the combustion parameters on the piston dynamics and
engine performance using the Wiebe function in a
free piston engine. Appl Energy 2013; 107:446–55.
[20] Tian CL, Feng HH, Zuo ZX. Oscillation
characteristic of single free piston engine
generator. Adv Mater Res 2011;383–390:1873–8.
[21] Feng HH, Song Y, Zuo ZX, Shang J, Wang YD,
Roskilly AP. Stable operation and
electricity generating characteristics of a single-cylinder
free piston engine linear generator: simulation and
experiments. Energies 2015; 8:765–85.
[22] Hung NB, Lim O, Iida N. The effects of key
parameters on the transition from SI
combustion to HCCI combustion in a two-stroke free
piston linear engine. Appl Energy 2015; 137:385–401.
[23] Chiang CJ, Yang JL, Lan SY, Shei TW, Chiang
WS, Chen BL. Dynamic modelling of SI/HCCI free-
piston engine generators.In: 6th IEEE conference on
industrial electronics and applications.
[24] Li QF, Xiao J, Huang Z. Simulation of a two-
stroke free-piston engine for electrical power
generation. Energy Fuel 2008; 22:3443–9.
[25] Lin J, Xu Z, Chang S, Yin N, Yan Thermodynamic
simulation and prototype
testing of a four-stroke free-piston engine. J Eng Gas
Turbines Power2014; 136:1–8.
[26] Li L, Luan Y, Wang Z, Deng J, Wu Z. Simulations
of key design parameters and
performance optimization for a free-piston engine. SAE
paper 2010-01-1105;
2010.
[27] Prados MA. Towards a linear engine PhD thesis.
Stanford University; 2002.
[28] Clark NN, Nandkumar S, Famouri P. Fundamental
analysis of a linear two-
cylinder internal combustion engine. SAE paper
982692; 1998.
[29] Mikalsen R, Roskilly AP. The fuel efficiency and
exhaust gas emissions of a low
heat rejection free-piston diesel engine. Proc IMech Part
A: J Power Energy
2009; 223:379–84.
[30] Johnson TA,Leick MT. Experimental evaluation
of the free piston engine-linear
alternator (FPLA), Sandia report no. SAND2015-2095.
Albuquerque,United
States: Sandia National Laboratories; 2015.
[31] Xu Z, Chang S. Prototype testing and analysis of a
novel internal combustion
linear generatorintegrated power system.Appl Energy
2010; 87:1342–8.
[32] Jia B, Smallbone A, Zuo Z, Feng H, Roskilly AP.
Design and simulation of a twoor
four-stroke free-piston engine generatorfor range
extender applications.
Energy Convers Manage 2016; 111:289–98.
[33] Goldsborough SS, Blarigan PV. Optimizing the
scavenging systemfor a two stroke
cycle, free piston engine for high efficiency and low
emissions: a
computational approach.SAE paper 2003-01-0001;
2003.
[34] Bergman M, Fredriksson J, Golovitchev V. CFD-
based optimization of a dieselfueled
free piston engine prototype for conventionaland HCCI
combustion.
SAE paper2008-01-2423; 2008.
[35] Fredriksson J, Bergman M, Golovitchev V,
Denbratt. Modeling the effect of
injection schedule change on free piston engine
operation. SAE paper 2006-010449;
2006.
[36] Bergman M, Golovitchev V. CFD modeling of a
two-stroke free piston energy
converter using detailed chemistry. SAE paper 2005-
24-074; 2005.
[37] Xia H, Pang Y, Grimble. Hybrid modeling and
control of a free-piston energy
converter. In: Proceedings of the 2006 IEEE
international conference on control
applications.
[38] Mikalsen R, Roskilly AP. A review of free-piston
engine history and application.
Appl Therm Eng 2007; 27:2339–52.
[39] Nagy CT, Clark NN. The linear engine in 2004.
SAE paper2005-01-2140;
2005.
[40] Kosaka H, Akita T, Moriya K, Goto S, Hotta Y,
Umeno T, et al. Development of
free piston engine linear generatorsystempart 1 –
investigation of
fundamental characteristics. SAE paper2014-01-1203;
2014.
[41] Berlinger WG, Raab FJ. Free piston engine with
electrical power output.US
patent no. 6541875 B1; April 1, 2003.
[42] Kos J. Free-piston engine without compressor. US
patent no. 4,924,956; May
15, 1990.
[43] Blarigan PV. Advanced internal combustion
electrical generator. In:
Proceedings of the 2001 DOE hydrogen program
review. p. 1–16.
[44] Huang L. An opposed-piston free-piston linear
generator development for
HEV. SAE paper 2012-01-1021; 2012.
[45] Yan H, Wang D, Xu Z. Design and simulation of
opposed-piston four-stroke
Shafeequr Rahman S.I et al., / Journal of Advanced Engineering Research, 2015, x (x), xxx-xxx
Research Article 7 www.jaeronline.com
free-piston linear generator. SAE paper 2015-01-1277;
2015.
[46] Washko FM, Winchell RA. Free piston
combustion engine design analysis and
challenges. SAE paper2015-32-0768; 2015.
[47] Galitello KA. Two stroke cycle engine. US patent
no. 4876991 A; October 31,
1989.
[48] Blarigan PV. Free-piston engine. US patent no.
6199519 B1; March 13, 2001.
[49] Rinderknecht F. The linear generatoras integral
component of an energy
converter for electric vehicles. In: European all-wheel
drive congress,Graz.
[51] Boldea I, Nasar SA. Permanent-magnet linear
alternators part 1: fundamental equations. IEEE Trans
Aerosp Electron Syst 1987; AES-23:73–8.
[52] Hong SK, Choi HY, Lim JW, Lim HJ, Jung HK.
Analysis of tubular-type linear generator for free-piston
engine. In: International conference on renewable
energies and power quality.
.

Mais conteúdo relacionado

Mais procurados

Enhancing the Efficiency of a Torque Converter Clutch (TCC)
Enhancing the Efficiency of a Torque Converter Clutch (TCC)Enhancing the Efficiency of a Torque Converter Clutch (TCC)
Enhancing the Efficiency of a Torque Converter Clutch (TCC)Sharon Lin
 
rajghat-power-house-new-delhi-training-report
rajghat-power-house-new-delhi-training-reportrajghat-power-house-new-delhi-training-report
rajghat-power-house-new-delhi-training-reportRaj Sharma
 
Pneumatic bike Presentation by Asif Mondal
Pneumatic bike Presentation by Asif MondalPneumatic bike Presentation by Asif Mondal
Pneumatic bike Presentation by Asif MondalAsifMondal8
 
Fluid power Engineering (Fluid coupling)
Fluid power Engineering (Fluid coupling)Fluid power Engineering (Fluid coupling)
Fluid power Engineering (Fluid coupling)Nilraj Vasandia
 
I.c. Engine Testing and Pollution Control
I.c. Engine Testing and Pollution ControlI.c. Engine Testing and Pollution Control
I.c. Engine Testing and Pollution ControlAditya Deshpande
 
Variable Compression Ratio engine
Variable Compression Ratio engineVariable Compression Ratio engine
Variable Compression Ratio engineDharmarth Jani
 
Variable compression ratio engine
Variable compression ratio engineVariable compression ratio engine
Variable compression ratio engineGokul Krishna
 
Diesel power plant
Diesel power plantDiesel power plant
Diesel power plantSiraskarCom
 
Fluid coupling with complete study resources
Fluid coupling with complete study resources Fluid coupling with complete study resources
Fluid coupling with complete study resources Muhammad Aslam Baig
 
Design, Modeling & Analysis of Pelton Wheel Turbine Blade
Design, Modeling & Analysis of Pelton Wheel Turbine BladeDesign, Modeling & Analysis of Pelton Wheel Turbine Blade
Design, Modeling & Analysis of Pelton Wheel Turbine BladeIJSRD
 
VARIABLE COMPRESSION RATIO ENGINE
VARIABLE COMPRESSION RATIO ENGINEVARIABLE COMPRESSION RATIO ENGINE
VARIABLE COMPRESSION RATIO ENGINEAjaymaddie
 
Day 07 Governor and Ignition System
Day 07 Governor and Ignition SystemDay 07 Governor and Ignition System
Day 07 Governor and Ignition SystemSuyog Khose
 
Compressed Air Powered Engine
Compressed Air Powered EngineCompressed Air Powered Engine
Compressed Air Powered EngineAbhishek Hingmire
 
Variable Valve Timing (VVT)
Variable Valve Timing (VVT)Variable Valve Timing (VVT)
Variable Valve Timing (VVT)Kaustubh Gaonkar
 
Variable compression ratio (vcr) engine a review
Variable compression ratio (vcr) engine  a reviewVariable compression ratio (vcr) engine  a review
Variable compression ratio (vcr) engine a reviewprjpublications
 
SMART GOVERNOR final ppt
SMART GOVERNOR final pptSMART GOVERNOR final ppt
SMART GOVERNOR final pptkharak kunwar
 

Mais procurados (20)

Enhancing the Efficiency of a Torque Converter Clutch (TCC)
Enhancing the Efficiency of a Torque Converter Clutch (TCC)Enhancing the Efficiency of a Torque Converter Clutch (TCC)
Enhancing the Efficiency of a Torque Converter Clutch (TCC)
 
BATCH B9 (1) (1)
BATCH B9 (1) (1)BATCH B9 (1) (1)
BATCH B9 (1) (1)
 
rajghat-power-house-new-delhi-training-report
rajghat-power-house-new-delhi-training-reportrajghat-power-house-new-delhi-training-report
rajghat-power-house-new-delhi-training-report
 
Pneumatic bike Presentation by Asif Mondal
Pneumatic bike Presentation by Asif MondalPneumatic bike Presentation by Asif Mondal
Pneumatic bike Presentation by Asif Mondal
 
Fluid power Engineering (Fluid coupling)
Fluid power Engineering (Fluid coupling)Fluid power Engineering (Fluid coupling)
Fluid power Engineering (Fluid coupling)
 
fluied power engineering
fluied power engineeringfluied power engineering
fluied power engineering
 
I.c. Engine Testing and Pollution Control
I.c. Engine Testing and Pollution ControlI.c. Engine Testing and Pollution Control
I.c. Engine Testing and Pollution Control
 
Variable Compression Ratio engine
Variable Compression Ratio engineVariable Compression Ratio engine
Variable Compression Ratio engine
 
Variable compression ratio engine
Variable compression ratio engineVariable compression ratio engine
Variable compression ratio engine
 
Diesel power plant
Diesel power plantDiesel power plant
Diesel power plant
 
Fluid coupling with complete study resources
Fluid coupling with complete study resources Fluid coupling with complete study resources
Fluid coupling with complete study resources
 
Design, Modeling & Analysis of Pelton Wheel Turbine Blade
Design, Modeling & Analysis of Pelton Wheel Turbine BladeDesign, Modeling & Analysis of Pelton Wheel Turbine Blade
Design, Modeling & Analysis of Pelton Wheel Turbine Blade
 
VARIABLE COMPRESSION RATIO ENGINE
VARIABLE COMPRESSION RATIO ENGINEVARIABLE COMPRESSION RATIO ENGINE
VARIABLE COMPRESSION RATIO ENGINE
 
Icengines testing
Icengines testingIcengines testing
Icengines testing
 
Day 07 Governor and Ignition System
Day 07 Governor and Ignition SystemDay 07 Governor and Ignition System
Day 07 Governor and Ignition System
 
Electronic governor
Electronic governorElectronic governor
Electronic governor
 
Compressed Air Powered Engine
Compressed Air Powered EngineCompressed Air Powered Engine
Compressed Air Powered Engine
 
Variable Valve Timing (VVT)
Variable Valve Timing (VVT)Variable Valve Timing (VVT)
Variable Valve Timing (VVT)
 
Variable compression ratio (vcr) engine a review
Variable compression ratio (vcr) engine  a reviewVariable compression ratio (vcr) engine  a review
Variable compression ratio (vcr) engine a review
 
SMART GOVERNOR final ppt
SMART GOVERNOR final pptSMART GOVERNOR final ppt
SMART GOVERNOR final ppt
 

Destaque

MODELLING AND FABRICATION OF GENEVA MECHANISM
MODELLING AND FABRICATION OF GENEVA MECHANISMMODELLING AND FABRICATION OF GENEVA MECHANISM
MODELLING AND FABRICATION OF GENEVA MECHANISMvignesh waran
 
Design & Fabrication of Film Frame by Geneva Mechanism
Design & Fabrication of Film Frame by Geneva MechanismDesign & Fabrication of Film Frame by Geneva Mechanism
Design & Fabrication of Film Frame by Geneva MechanismSuchit Moon
 
Dual clutch
Dual clutch Dual clutch
Dual clutch hardybist
 
Dual clutch Transmission
Dual clutch TransmissionDual clutch Transmission
Dual clutch TransmissionBisal Karmakar
 
Dual clutch transmission seminar report
Dual clutch transmission seminar reportDual clutch transmission seminar report
Dual clutch transmission seminar reportDeepak kango
 
Piston- Internal Combustion Engine
Piston- Internal Combustion EnginePiston- Internal Combustion Engine
Piston- Internal Combustion EngineDanny Joel
 
LinkedIn SlideShare: Knowledge, Well-Presented
LinkedIn SlideShare: Knowledge, Well-PresentedLinkedIn SlideShare: Knowledge, Well-Presented
LinkedIn SlideShare: Knowledge, Well-PresentedSlideShare
 
New Toyota 1.2l petrol engine
New Toyota 1.2l petrol engineNew Toyota 1.2l petrol engine
New Toyota 1.2l petrol engineRushLane
 
HCCI Engines Fueled with Ethanol
HCCI Engines Fueled with EthanolHCCI Engines Fueled with Ethanol
HCCI Engines Fueled with Ethanolalilimam2
 
Gowtham Moorth1
Gowtham Moorth1Gowtham Moorth1
Gowtham Moorth1Gowtham M
 
HCCI Engine Performance Evaluation Using FORTE
HCCI Engine Performance Evaluation Using FORTEHCCI Engine Performance Evaluation Using FORTE
HCCI Engine Performance Evaluation Using FORTEReaction Design
 
Generation of electrcity from gasoline engine waste heat
Generation of electrcity from gasoline engine waste heatGeneration of electrcity from gasoline engine waste heat
Generation of electrcity from gasoline engine waste heatAlexander Decker
 
Dual Clutch Transmission System
Dual Clutch Transmission SystemDual Clutch Transmission System
Dual Clutch Transmission SystemNeel Thakkar
 
Generation of electricity using the flow or velocity of vehicle exhaust gas
Generation of electricity using the flow or velocity of vehicle exhaust gasGeneration of electricity using the flow or velocity of vehicle exhaust gas
Generation of electricity using the flow or velocity of vehicle exhaust gasVel Murugan
 
Theory of machines: Shaper Feed Mechanism
Theory of machines: Shaper Feed MechanismTheory of machines: Shaper Feed Mechanism
Theory of machines: Shaper Feed MechanismMohamed Abd El-Moniem
 
Fire ball extinguisher
Fire ball extinguisherFire ball extinguisher
Fire ball extinguisherTanvay Shinde
 
Paper cutting & rewinding machine project report sreesangh p ghosh
Paper cutting & rewinding machine   project report sreesangh p ghoshPaper cutting & rewinding machine   project report sreesangh p ghosh
Paper cutting & rewinding machine project report sreesangh p ghoshSreesangh P Ghosh
 

Destaque (20)

MODELLING AND FABRICATION OF GENEVA MECHANISM
MODELLING AND FABRICATION OF GENEVA MECHANISMMODELLING AND FABRICATION OF GENEVA MECHANISM
MODELLING AND FABRICATION OF GENEVA MECHANISM
 
Design & Fabrication of Film Frame by Geneva Mechanism
Design & Fabrication of Film Frame by Geneva MechanismDesign & Fabrication of Film Frame by Geneva Mechanism
Design & Fabrication of Film Frame by Geneva Mechanism
 
Dual clutch
Dual clutch Dual clutch
Dual clutch
 
Dual clutch Transmission
Dual clutch TransmissionDual clutch Transmission
Dual clutch Transmission
 
Dual clutch transmission seminar report
Dual clutch transmission seminar reportDual clutch transmission seminar report
Dual clutch transmission seminar report
 
Dual clutch-transmission
Dual clutch-transmissionDual clutch-transmission
Dual clutch-transmission
 
Piston- Internal Combustion Engine
Piston- Internal Combustion EnginePiston- Internal Combustion Engine
Piston- Internal Combustion Engine
 
LinkedIn SlideShare: Knowledge, Well-Presented
LinkedIn SlideShare: Knowledge, Well-PresentedLinkedIn SlideShare: Knowledge, Well-Presented
LinkedIn SlideShare: Knowledge, Well-Presented
 
New Toyota 1.2l petrol engine
New Toyota 1.2l petrol engineNew Toyota 1.2l petrol engine
New Toyota 1.2l petrol engine
 
HCCI Engines Fueled with Ethanol
HCCI Engines Fueled with EthanolHCCI Engines Fueled with Ethanol
HCCI Engines Fueled with Ethanol
 
Gowtham Moorth1
Gowtham Moorth1Gowtham Moorth1
Gowtham Moorth1
 
Hcci engines
Hcci enginesHcci engines
Hcci engines
 
AUE 893
AUE 893AUE 893
AUE 893
 
HCCI Engine Performance Evaluation Using FORTE
HCCI Engine Performance Evaluation Using FORTEHCCI Engine Performance Evaluation Using FORTE
HCCI Engine Performance Evaluation Using FORTE
 
Generation of electrcity from gasoline engine waste heat
Generation of electrcity from gasoline engine waste heatGeneration of electrcity from gasoline engine waste heat
Generation of electrcity from gasoline engine waste heat
 
Dual Clutch Transmission System
Dual Clutch Transmission SystemDual Clutch Transmission System
Dual Clutch Transmission System
 
Generation of electricity using the flow or velocity of vehicle exhaust gas
Generation of electricity using the flow or velocity of vehicle exhaust gasGeneration of electricity using the flow or velocity of vehicle exhaust gas
Generation of electricity using the flow or velocity of vehicle exhaust gas
 
Theory of machines: Shaper Feed Mechanism
Theory of machines: Shaper Feed MechanismTheory of machines: Shaper Feed Mechanism
Theory of machines: Shaper Feed Mechanism
 
Fire ball extinguisher
Fire ball extinguisherFire ball extinguisher
Fire ball extinguisher
 
Paper cutting & rewinding machine project report sreesangh p ghosh
Paper cutting & rewinding machine   project report sreesangh p ghoshPaper cutting & rewinding machine   project report sreesangh p ghosh
Paper cutting & rewinding machine project report sreesangh p ghosh
 

Semelhante a Free Piston Linear Engine[FPLE]- A Review

Design of Industrial Electro-Hydraulic Valves, New Approach
Design of Industrial Electro-Hydraulic Valves, New ApproachDesign of Industrial Electro-Hydraulic Valves, New Approach
Design of Industrial Electro-Hydraulic Valves, New ApproachIJERA Editor
 
3 engine dynamic properties
3 engine dynamic properties3 engine dynamic properties
3 engine dynamic propertiesChandel Anamica
 
DESIGN AND FABRICATION OF DISC TYPE HYBRID TURBINE-PUMP
DESIGN AND FABRICATION OF DISC TYPE HYBRID TURBINE-PUMPDESIGN AND FABRICATION OF DISC TYPE HYBRID TURBINE-PUMP
DESIGN AND FABRICATION OF DISC TYPE HYBRID TURBINE-PUMPDenny John
 
Crimson Publishers-Free-Piston Engine (FPE) Technology with Different Applica...
Crimson Publishers-Free-Piston Engine (FPE) Technology with Different Applica...Crimson Publishers-Free-Piston Engine (FPE) Technology with Different Applica...
Crimson Publishers-Free-Piston Engine (FPE) Technology with Different Applica...Crimsonpublishers-Mechanicalengineering
 
Slider Crank Mechanism for Four bar linkage
Slider Crank Mechanism for Four bar linkageSlider Crank Mechanism for Four bar linkage
Slider Crank Mechanism for Four bar linkageijsrd.com
 
Design Model-free Fuzzy Sliding Mode Control of Internal Combustion Engine
Design Model-free Fuzzy Sliding Mode Control of Internal Combustion EngineDesign Model-free Fuzzy Sliding Mode Control of Internal Combustion Engine
Design Model-free Fuzzy Sliding Mode Control of Internal Combustion EngineCSCJournals
 
IRJET- A Review of Testing of Multi Cylinder S.I. Petrol Engine
IRJET-  	  A Review of Testing of Multi Cylinder S.I. Petrol EngineIRJET-  	  A Review of Testing of Multi Cylinder S.I. Petrol Engine
IRJET- A Review of Testing of Multi Cylinder S.I. Petrol EngineIRJET Journal
 
Analysis of-change-in-intake-manifold-length-and-development-of-variable-inta...
Analysis of-change-in-intake-manifold-length-and-development-of-variable-inta...Analysis of-change-in-intake-manifold-length-and-development-of-variable-inta...
Analysis of-change-in-intake-manifold-length-and-development-of-variable-inta...Mohit Soni
 
4. compressed air engine
4. compressed air engine4. compressed air engine
4. compressed air engineMubashar Sharif
 
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLES
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLESDTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLES
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLESijics
 
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLES
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLESDTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLES
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLESijcisjournal
 
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLES
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLESDTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLES
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLESijcisjournal
 
IRJET- Design and Analysis of V6 Solenoid Engine
IRJET- Design and Analysis of V6 Solenoid EngineIRJET- Design and Analysis of V6 Solenoid Engine
IRJET- Design and Analysis of V6 Solenoid EngineIRJET Journal
 

Semelhante a Free Piston Linear Engine[FPLE]- A Review (20)

Design of Industrial Electro-Hydraulic Valves, New Approach
Design of Industrial Electro-Hydraulic Valves, New ApproachDesign of Industrial Electro-Hydraulic Valves, New Approach
Design of Industrial Electro-Hydraulic Valves, New Approach
 
3 engine dynamic properties
3 engine dynamic properties3 engine dynamic properties
3 engine dynamic properties
 
DESIGN AND FABRICATION OF DISC TYPE HYBRID TURBINE-PUMP
DESIGN AND FABRICATION OF DISC TYPE HYBRID TURBINE-PUMPDESIGN AND FABRICATION OF DISC TYPE HYBRID TURBINE-PUMP
DESIGN AND FABRICATION OF DISC TYPE HYBRID TURBINE-PUMP
 
Crimson Publishers-Free-Piston Engine (FPE) Technology with Different Applica...
Crimson Publishers-Free-Piston Engine (FPE) Technology with Different Applica...Crimson Publishers-Free-Piston Engine (FPE) Technology with Different Applica...
Crimson Publishers-Free-Piston Engine (FPE) Technology with Different Applica...
 
D045021025
D045021025D045021025
D045021025
 
Slider Crank Mechanism for Four bar linkage
Slider Crank Mechanism for Four bar linkageSlider Crank Mechanism for Four bar linkage
Slider Crank Mechanism for Four bar linkage
 
Flywheel
FlywheelFlywheel
Flywheel
 
Design Model-free Fuzzy Sliding Mode Control of Internal Combustion Engine
Design Model-free Fuzzy Sliding Mode Control of Internal Combustion EngineDesign Model-free Fuzzy Sliding Mode Control of Internal Combustion Engine
Design Model-free Fuzzy Sliding Mode Control of Internal Combustion Engine
 
Al4101216220
Al4101216220Al4101216220
Al4101216220
 
IRJET- A Review of Testing of Multi Cylinder S.I. Petrol Engine
IRJET-  	  A Review of Testing of Multi Cylinder S.I. Petrol EngineIRJET-  	  A Review of Testing of Multi Cylinder S.I. Petrol Engine
IRJET- A Review of Testing of Multi Cylinder S.I. Petrol Engine
 
Analysis of-change-in-intake-manifold-length-and-development-of-variable-inta...
Analysis of-change-in-intake-manifold-length-and-development-of-variable-inta...Analysis of-change-in-intake-manifold-length-and-development-of-variable-inta...
Analysis of-change-in-intake-manifold-length-and-development-of-variable-inta...
 
B012410616
B012410616B012410616
B012410616
 
4. compressed air engine
4. compressed air engine4. compressed air engine
4. compressed air engine
 
30120140507014
3012014050701430120140507014
30120140507014
 
30120140507014
3012014050701430120140507014
30120140507014
 
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLES
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLESDTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLES
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLES
 
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLES
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLESDTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLES
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLES
 
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLES
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLESDTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLES
DTC CONTROL OF BLAC AND BLDC MOTORS FOR PURE ELECTRIC VEHICLES
 
IRJET- Design and Analysis of V6 Solenoid Engine
IRJET- Design and Analysis of V6 Solenoid EngineIRJET- Design and Analysis of V6 Solenoid Engine
IRJET- Design and Analysis of V6 Solenoid Engine
 
engine_performance.pptx
engine_performance.pptxengine_performance.pptx
engine_performance.pptx
 

Último

Centering equity and the community in Transportation by Richard Ezike
Centering equity and the community in Transportation by Richard EzikeCentering equity and the community in Transportation by Richard Ezike
Centering equity and the community in Transportation by Richard EzikeForth
 
Transportation Electrification Funding Strategy.pptx
Transportation Electrification Funding Strategy.pptxTransportation Electrification Funding Strategy.pptx
Transportation Electrification Funding Strategy.pptxForth
 
Building a Future Where Everyone Can Ride and Drive Electric by Linda Bailey
Building a Future Where Everyone Can Ride and Drive Electric by Linda BaileyBuilding a Future Where Everyone Can Ride and Drive Electric by Linda Bailey
Building a Future Where Everyone Can Ride and Drive Electric by Linda BaileyForth
 
Centering Equity and Community in Transportation by Benito Perez
Centering Equity and Community in Transportation by Benito PerezCentering Equity and Community in Transportation by Benito Perez
Centering Equity and Community in Transportation by Benito PerezForth
 
Centering Equity Presentation by Brenna Rivett
Centering Equity Presentation by Brenna RivettCentering Equity Presentation by Brenna Rivett
Centering Equity Presentation by Brenna RivettForth
 
Program Design by Prateek Suri and Shakaya Cooper
Program Design by Prateek Suri and Shakaya CooperProgram Design by Prateek Suri and Shakaya Cooper
Program Design by Prateek Suri and Shakaya CooperForth
 
Design and Fund Equitable Electric Transportation For Communities by Jasmine ...
Design and Fund Equitable Electric Transportation For Communities by Jasmine ...Design and Fund Equitable Electric Transportation For Communities by Jasmine ...
Design and Fund Equitable Electric Transportation For Communities by Jasmine ...Forth
 
Lakshitha maduranga CV - for data entry clerck
Lakshitha maduranga CV - for data entry clerckLakshitha maduranga CV - for data entry clerck
Lakshitha maduranga CV - for data entry clerckLakshanMadhushanka3
 
USDA’s EV Charging Infrastructure Solutions by Chris McLean
USDA’s EV Charging Infrastructure Solutionsby Chris McLeanUSDA’s EV Charging Infrastructure Solutionsby Chris McLean
USDA’s EV Charging Infrastructure Solutions by Chris McLeanForth
 
Study on Financing of zero-emission trucks and their infrastructure
Study on Financing of zero-emission trucks and their infrastructureStudy on Financing of zero-emission trucks and their infrastructure
Study on Financing of zero-emission trucks and their infrastructureEuropeanCleanTruckin
 
Equity Lab: Inked with Intent by The Greenlining Institute
Equity Lab: Inked with Intent by The Greenlining InstituteEquity Lab: Inked with Intent by The Greenlining Institute
Equity Lab: Inked with Intent by The Greenlining InstituteForth
 
Environmental and Climate Justice Programby Karen Campblin
Environmental and Climate Justice Programby Karen CampblinEnvironmental and Climate Justice Programby Karen Campblin
Environmental and Climate Justice Programby Karen CampblinForth
 
Building a Budget by Jeff Allen and Josh Rodriguez
Building a Budget by Jeff Allen and Josh RodriguezBuilding a Budget by Jeff Allen and Josh Rodriguez
Building a Budget by Jeff Allen and Josh RodriguezForth
 
Nosfdsfsdfasdfasdfasdfsadf asdfasdfasdfasdf
Nosfdsfsdfasdfasdfasdfsadf asdfasdfasdfasdfNosfdsfsdfasdfasdfasdfsadf asdfasdfasdfasdf
Nosfdsfsdfasdfasdfasdfsadf asdfasdfasdfasdfJulia Kaye
 
Commercial Extractor fan repair services
Commercial Extractor fan repair servicesCommercial Extractor fan repair services
Commercial Extractor fan repair servicesmb1294198
 

Último (17)

Reinventing the Car - as I reported it in 1985!
Reinventing the Car - as I reported it in 1985!Reinventing the Car - as I reported it in 1985!
Reinventing the Car - as I reported it in 1985!
 
Centering equity and the community in Transportation by Richard Ezike
Centering equity and the community in Transportation by Richard EzikeCentering equity and the community in Transportation by Richard Ezike
Centering equity and the community in Transportation by Richard Ezike
 
Transportation Electrification Funding Strategy.pptx
Transportation Electrification Funding Strategy.pptxTransportation Electrification Funding Strategy.pptx
Transportation Electrification Funding Strategy.pptx
 
Building a Future Where Everyone Can Ride and Drive Electric by Linda Bailey
Building a Future Where Everyone Can Ride and Drive Electric by Linda BaileyBuilding a Future Where Everyone Can Ride and Drive Electric by Linda Bailey
Building a Future Where Everyone Can Ride and Drive Electric by Linda Bailey
 
Centering Equity and Community in Transportation by Benito Perez
Centering Equity and Community in Transportation by Benito PerezCentering Equity and Community in Transportation by Benito Perez
Centering Equity and Community in Transportation by Benito Perez
 
Centering Equity Presentation by Brenna Rivett
Centering Equity Presentation by Brenna RivettCentering Equity Presentation by Brenna Rivett
Centering Equity Presentation by Brenna Rivett
 
EVAT - Future Mobility Transformation in Thailand
EVAT - Future Mobility Transformation in ThailandEVAT - Future Mobility Transformation in Thailand
EVAT - Future Mobility Transformation in Thailand
 
Program Design by Prateek Suri and Shakaya Cooper
Program Design by Prateek Suri and Shakaya CooperProgram Design by Prateek Suri and Shakaya Cooper
Program Design by Prateek Suri and Shakaya Cooper
 
Design and Fund Equitable Electric Transportation For Communities by Jasmine ...
Design and Fund Equitable Electric Transportation For Communities by Jasmine ...Design and Fund Equitable Electric Transportation For Communities by Jasmine ...
Design and Fund Equitable Electric Transportation For Communities by Jasmine ...
 
Lakshitha maduranga CV - for data entry clerck
Lakshitha maduranga CV - for data entry clerckLakshitha maduranga CV - for data entry clerck
Lakshitha maduranga CV - for data entry clerck
 
USDA’s EV Charging Infrastructure Solutions by Chris McLean
USDA’s EV Charging Infrastructure Solutionsby Chris McLeanUSDA’s EV Charging Infrastructure Solutionsby Chris McLean
USDA’s EV Charging Infrastructure Solutions by Chris McLean
 
Study on Financing of zero-emission trucks and their infrastructure
Study on Financing of zero-emission trucks and their infrastructureStudy on Financing of zero-emission trucks and their infrastructure
Study on Financing of zero-emission trucks and their infrastructure
 
Equity Lab: Inked with Intent by The Greenlining Institute
Equity Lab: Inked with Intent by The Greenlining InstituteEquity Lab: Inked with Intent by The Greenlining Institute
Equity Lab: Inked with Intent by The Greenlining Institute
 
Environmental and Climate Justice Programby Karen Campblin
Environmental and Climate Justice Programby Karen CampblinEnvironmental and Climate Justice Programby Karen Campblin
Environmental and Climate Justice Programby Karen Campblin
 
Building a Budget by Jeff Allen and Josh Rodriguez
Building a Budget by Jeff Allen and Josh RodriguezBuilding a Budget by Jeff Allen and Josh Rodriguez
Building a Budget by Jeff Allen and Josh Rodriguez
 
Nosfdsfsdfasdfasdfasdfsadf asdfasdfasdfasdf
Nosfdsfsdfasdfasdfasdfsadf asdfasdfasdfasdfNosfdsfsdfasdfasdfasdfsadf asdfasdfasdfasdf
Nosfdsfsdfasdfasdfasdfsadf asdfasdfasdfasdf
 
Commercial Extractor fan repair services
Commercial Extractor fan repair servicesCommercial Extractor fan repair services
Commercial Extractor fan repair services
 

Free Piston Linear Engine[FPLE]- A Review

  • 1. Journal of Advanced Engineering Research ISSN: 2393-8447 Volume 2, Issue X, 2015, pp.XX-XX Research Article 1 www.jaeronline.com FREE PISTON LINEAR ENGINE [FPLE]- A REVIEW Shafeequr Rahman S. I1*, Surya Kandhaswamy T2, Dr. P. Gopal3 1Department of Automobile Engineering, Anna University, Tiruchirappalli-620024, India 2Department of Automobile Engineering, Anna University, Tiruchirappalli-620024, India 3Asst. Prof, Department of Automobile Engineering, Anna University, Tiruchirappalli-620024, India *Corresponding author email: shafeeq16101995@gmail.com , Tel. :8754222018 ABSTRACT Unlike conventionalinternal combustion engines,a free-piston linear engine has no a crankshaft, and thus the pistons move freely in the cylinder. This allows a free-piston linear engine to easily adjust the compression ratio and optimize the combustion process. Free-piston linear engines include two main parts: a free-piston engine and a linear alternator. The free-piston engine is classified into three main types:single piston,dual piston, and opposed piston.The linear alternator is generally categorized as flat-type or tubular-type. Free-piston linear engines can operate with multi-fuel and HCCI combustion because of their variable compression ratios. Furthermore, they are used to generate the electric power applied in hybrid electric vehicles. To promote understanding of the unique features of free-piston linear engines, this paper presents a review of their different designs and operating characteristics. We also discuss the varied experimental systems and applications of free-piston linear engines Keywords – FPLE, Free piston, Linear engine, FPEG 1. INTRODUCTION The free-piston linear engine (FPLE) is a linear energy conversion system, and the term ‘free-piston’ is widely used to distinguish its linear characteristics from those of a conventional reciprocating engine. Without the limitation of the crankshaft mechanism, as known for the conventional engines, the piston is free to oscillate between its dead centers.The piston assembly is the only significant moving component for the FPLEs, and its movement is determined by the gas and load forces acting upon it. During the operation of FPLEs, combustion takes place in the internal combustion chamber, and the high pressure exhaust gas pushes the piston assembly backwards. The chemical energy from the air fuel mixture is then converted to the mechanical energy of the moving piston assembly. Due to this linear characteristic, a FPLE requires a linear load to convert this mechanical energy for the usage of the target application. As the load is coupled directly to the piston assembly, the technical requirements for the free-piston engine loads are high, which are summarized as: (1) The load must provide satisfactory energy conversion efficiency to make the overall systemefficient. (2) The load may be subjected to high velocity (3) The load may be subjected to high force from the cylinder gas. (4) The load device may be subjected to heat transfer from the engine cylinders (5) The size, moving mass and load force profile are feasible to be coupled with the designed FPEs. Reported load devices for the FPEs include air compressors, electric generators and hydraulic pumps.In this research, the FPE is connected with a linear electric generator (free-piston engine generator, FPEG) and is investigated with the objective to utilize the configuration within a hybrid-electric automotive vehicle power system. Since the FPEG was first proposed, it has attracted interest from all over the world. Different research methods and prototype designs have been reported using the FPLE concept.However, to date, none of these have been commercially realized in part due to the challenges of system control. In conventional engines, the crankshaft mechanism provides piston motion control, defining both the outer positions of the piston motion (the dead centers) and the piston motion profile. Due to the high inertia of the crankshaft system, the piston motion cannot be influenced in the timeframe of one cycle. In the free- piston engine, the piston motion is determined by the instantaneous sumofthe forces acting on the mover, and the piston motion is therefore influenced by the progress of the combustion process.Moreover, the piston motion profile may be different for different operating conditions.Variations between consecutive cycles due to cycle-to-cycle variations in the in-cylinder processes are
  • 2. Shafeequr Rahman S.I et al., / Journal of Advanced Engineering Research, 2015, x (x), xxx-xxx Research Article 2 www.jaeronline.com also possible.Overcome controlling of the FPLE engine is a challenging task. 2. Classification ofFPLEs 2.1. NUMBER OF STROKES Similar to traditional internal combustion engines, FPLEs are classified into four-stroke and two-stroke engines. The strokes of a four-stroke FPLE are intake, compression, combustion, and exhaust. In a traditional internal combustion engine with a crankshaft mechanism, the four strokes happen in two revolutions of the crankshaft, and the combustion stroke is called the power stroke. For FPLEs, the four strokes occur in the linear motion of the piston, and the intake and exhaust valves are controlled by an electronic system. Xu and Chang [31] studied the motion control of a four stroke FPLE developed for electric power generation. The piston strokes combined with the open/close timing of the intake and exhaust valves were electronically controlled. Even though the four-stroke principle can be applied to FPLEs, it presents greatertechnicalchallenges for motion control than two-stroke engines. The technical challenges for motion control of the four-stroke FPLE include the complex control of the opening/closing times of the intake and exhaust valves vis-à-vis the linear motion of the piston. The opening/closing times of the intake and exhaust valves must be controlled correctly to prevent a collision between them and the piston crown. Therefore, four- stroke FPLEs have been investigated less than two- stroke FPLEs, which simplify the engine structure and improve motion control. Jia et al [32]. simulated the piston dynamics and thermodynamics of a two- or four- stroke FPLE. For the two-stroke cycle, the linear generator was used only as a generator, whereas it functioned as both a motor and a generator in the four-stroke cycle. They found that the piston speed during the expansion process ofthe four-stroke cycle was higher than that ofthe two-stroke cycle. However, for the non-power strokes of the four-stroke cycle, the piston speed was much lower because of the brake force of the motor, as shown in Fig. 1. They also showed that the heat release process was more aligned with a constant volume process when the FPLE operated in two-stroke mode, and the peak cylinder pressure of four-stroke cycle was higher than that of the two-stroke cycle, as shown in Fig. 2. This can be explained by increasing of piston displacement in the four-stroke cycle. As can be seen in the displacement of the piston in the four-stroke cycle was significantly longer than that in the two-stroke cycle because in the four-stroke cycle, piston movement could be controlled by optimizing the motor forces. To ensure stable and smooth engine operation using a four-stroke cycle, the authors proposed a more complex and robust control system. Their simulation results also indicated that the indicated power and electric power of the two- stroke cycle were much higher than those of the four- stroke cycle with the same throttle opening. Because the electric power generated in the four- stroke cycle was used to compensate for the overall power consumption during the motoring processes. The strokes of the most typical two-stroke FPLE are scavenging compression and combustion–expansion. The scavenging process occurs in different ways depending on the engine type. Goldsborough and Blarigan [33] presented an optimal study for the scavenging system of a two-stroke FPLE. They investigated a wide range of design options, including loop, hybrid-loop, and uniflow scavenging methods.The uniflow method uses the exhaust valve to liberate exhaust gas during the scavenging process.Locating the exhaust valves in the cylinder head ensures better flushing at the top of the combustion chamber, but increases the mechanical complexity of the engine because the valves must be actuated. Two stroke FPLEs using the uniflow scavenging method are also found in other studies. 2.2. PISTON CONFIGURATION In general, FPLEs can be classified into three piston types: single piston, double piston (dual piston and opposed piston), and four pistons (dual piston, opposed piston, and complex piston configuration), Of those, the single-piston engine has a simple design with higher controllability than the other FPLEs; however, the dynamic balance is not good because it has only one piston.Mikalsen and Roskilly [16] proposed a prototype of a single-piston FPLE for electric power generation in large scale systems. Their engine includes a combustion cylinder, a bounce chamber cylinder, and a linear electric machine. In this engine, the amount of air contained in the bounce chamber is varied by controlvalves to change the force coming from the bounce chamber. Tian et al. replaced the bounce chamber with a rebound spring. This allowed a simpler design, compared with the design of Mikalsen and Roskilly [17] So far, the single-piston FPLE is the closest to a commercial system because it offers the simplest configuration and high controllability. Kosaka et al [40]. developed a prototype single piston FPLE using a cooling and lubricating systemalong with control system logic, which contributed significantly to commercialization of an FPLE. Their single piston FPLE used a cooling oil passage and a water-cooled cylinder head. A perfectly balanced design is the main advantage of opposed piston configurations,but those designsmake engines complicated. Pontus Ostenberg [5] presented an early opposed-piston FPLE in 1943, Therein, a denotes a free-piston engine with opposed pistons (piston 2 and
  • 3. Shafeequr Rahman S.I et al., / Journal of Advanced Engineering Research, 2015, x (x), xxx-xxx Research Article 3 www.jaeronline.com piston 2a), and B denotes a single-phase linear alternator. In Pontus Ostenberg’s [5] engine. 3.2. Combustion characteristics 3.2.1. Spark ignition combustion Similar to a traditional internal combustion engine, an SI FPLE uses sparkplugs installed in the cylinder head to ignite the air/fuel mixture in the cylinder when generating power. To investigate the combustion characteristics of an SI FPLE, many studies have been conducted,including both simulations and experiments. Mikalsen and Roskilly [15] compared the performance of an SI-FPLE with that of a conventionalengine using a computational fluid dynamics (CFD) simulation model. They showed that the FPLE obtained a slight efficiency advantage overthe conventionalengine at low speeds,but that the efficiency of the free-piston engine dropped as the speed increased because the effects of volume change during combustion were greater at higher speeds. They also found that the free-piston engine is lower than that of the traditional hydrogen engine, this engine had a slight benefit in NO emissions when compared with the conventionalengine, Because the shortertime spent around TDC and the faster expansion in the free piston engine influenced the NOx levels Yuan et al also showed a lower level of NO emissions in a free-piston hydrogen engine compared with a traditional hydrogen engine. Because the mean in-cylinder gas temperature of the free-piston hydrogen x 3.2.2. Compression ignition combustion CI in an internal combustion engine is a process in which the necessary high temperature is produced by compressing the air in the cylinder before the fuel is injected into the combustion chamber. For FPLEs, CI is generally investigated with diesel fuel Mao et al. presented a simulation study of a free-piston diesel engine using a zero-dimensional numerical simulation combined with a CFD model (AVL-FIRE) to simulate the gas exchange and combustion processes. They used the two-stage Wiebe function to model the combustion process in time, one stage for premixed and one stage for diffusive combustion. They derived the ignition delay and combustion duration from the CFD calculation for diesel FPLE combustion. In another simulation study, Mikalsen and Roskilly [11] investigated the combustion process ofa free-piston diesel engine using a CFD model (Open FOAM) and compared the results with those from a conventional engine.They found that the free-piston diesel engine had a higher heat release rate from the pre-mixed combustion phase because of an increased ignition delay, compared with the conventional engine. In another simulation study conducted by Mikalsen and Roskilly [15], they compared the simulation results of a two-stroke free piston CI engine with those from a respective conventional CI engine. Therein, a single-zone model was used to simulate combustion, while in-cylinder heat transfer was modeled according to Hohenberg. They found that the indicated efficiency of the free-piston engine was higher than that of the conventional engine because of reduced heat transfer losses and lower frictional losses. Both peak gas temperature and temperature levels during expansion were lower in the free-piston engine, and that resulted in lower heat transfer losses. Yuan et al investigated the combustion characteristics of a free-piston diesel engine coupling with dynamic and scavenging models. Their coupled model used an empirical heat release model of the Wiebe function to calculate the piston motion profile based on the initial boundary conditions. They used a scavenging CFD model to calculate the gas exchange performances according to the calculated piston motion. They then imported the calculated scavenging results and piston motion into a combustion CFD model to calculate the combustion performances and fed those results with the gas exchange results back to the dynamic model to calculate the next iteration. Afterward, they’re established the scavenging CFD model and calculated a new using the updated results from piston motion and combustion, repeating the procedure until they met the iterative convergence conditions. Their simulation results showed benefits for reducing temperature dependent emissions (NO) because the in-cylinder average gas temperature ofthe free-piston engine was generally lower than that of the traditional engine. This is also similar to the results obtained by Mikalsen and Roskilly [11] However, Chenheng Yuan found that a free-piston engine had no advantage in particulate emissions when compared with a traditional crank engine, Shoukry et al. presented a numerical simulation for a parametric study of a two-stroke direct- injection linear engine fueled with diesel. They investigated the effects of parameters such as load constant, reciprocating mass, injection timing, and combustion duration on the dynamic and combustion characteristics of an FPLE, defining injection timing as piston position before the maximum possible stroke. To simulate the combustion process, they used the Wiebe function converted to time and calculated the heat transfer based on the Woschni model. Their simulation results showed that the increased reciprocating mass increased the piston stroke and peak in-cylinder combustion pressure by increasing the inertial force. The change of injection timing also contributed to increasing the peak in-cylinder combustion pressure.Adjusting the injection timing closer to the maximum stroke led to higher in-cylinder combustion pressure because of
  • 4. Shafeequr Rahman S.I et al., / Journal of Advanced Engineering Research, 2015, x (x), xxx-xxx Research Article 4 www.jaeronline.com moving the combustion event toward that of the ideal Otto case. 3.5.2. Homogenous charge compression ignition Homogenous charge compression ignition (HCCI) engines compress a premixed charge until it self-ignites, resulting in very rapid combustion but with poor control of ignition timing. The free-piston engine is well suited for this since the requirements for accurate ignition timing control are lower than in conventional engines. Potential advantages of HCCI include high efficiencies due to close to constant volume combustion and the possibility to burn lean mixtures to reduce gas temperatures and thereby some types of emissions. HCCI operation of free-piston engines has been attempted by among others Aichlmayr and van Blarigan[48]. A quasi-HCCI approach is mentioned by Hibi and Ito. Diesel fuel is injected very early in the compression process but after the intake and exhaust ports have closed. The fuel does not ignite at injection because the temperature 4.2. Applications ofFPLE FPLEs are used to convert chemical energy stored in fuel into electrical energy. They have been investigated and developed by scientists and researchers around the world. The high efficiency of a linear alternator combined with the simple structures of a free-piston engine are prompting researchers to further develop FPLEs for hybrid electric vehicles (HEVs). A group of authors from General Motors and West Virginia University provided an integrated design methodology to select a free-piston engine and linear alternator combination for use as an HEV auxiliary power unit. They developed integrated models of the engine and linear alternator and simulated the electric power output while varying systemparameters. They also presented an optimization method for selecting the design that best met output voltage and power requirements. Goertz and Peng[13] reviewed feasible hybrid powertrain concepts, evaluating them based on additional weight, power per size, fuel efficiency, reliability, local emissions, production costs, comfort, safety, and development risk. They found that a free- piston engine coupled with a linear alternator and battery was the most promising candidate for a high-efficiency hybrid vehicle. In a simulation study, Huang developed an opposed-piston FPLE for an HEV. The simulation results showed that the newly designed FPLE was feasible and could obtain a 15 kW average electric power output with a generating efficiency of 42.5%. Carter and Wechner[14] designed an FPLE to meet the highest levels of fuel efficiency and exhaust emissions performance in a compact size for use in HEVs. Their FPLE was a combination of a free-piston engine and an integral generatorand included an integral compressor and a passive intake valve in the head of the piston, which eliminated common FPLE problems such as piston ring wear and the need for an external compressor, and allowed a significant increase in power density.Cosic et al. compared the totalefficiency of a 12- ton truck HEV using a conventional combustion engine and an FPLE. They found that replacing a conventional combustion engine with an FPLE increased the total efficiency of the system by 25%. Hansson et al investigated the performance gain achieved by using an FPLE in a medium-sized HEV, compared with a conventional diesel-generator, and found a potential decrease in fuel consumption of up to 19% when using the equivalent consumption minimization strategy (ECMS), A group of researchers at Toyota Central R&D Labs Inc. is developing a prototype 10 kW FPLE for electric drive vehicles with a thin and compact design, high efficiency, and high fuel flexibility. This prototype includes a two stroke combustion chamber, a linear alternator, and a gas spring chamber. Its main feature is a stepped piston shape that Toyota calls a ‘‘W-shape” that has advantages such as decreased heat loss from the gas spring chamber, a hollow structure to ensure piston cooling, improved generating efficiency because of a small clearance between the magnet and the coil, and a heated magnet to prevented degaussing. 5. CONCLUSION In this paper, we have reviewed and summarized the literature on FPLEs with varied designs and operating features. For piston stroke type, two-stroke FPLEs are most-commonly investigated and developed because of their advantages in structure and control. Published results show that dual-piston FPLEs have a higher power/weight ratio than other piston arrangements. However, the combustion process occurs alternately in each cylinder in a dual-piston engine, which leads to varied combustion pressure at each cylinder and engine cycle. Meanwhile, single-piston FPLEs have a simple design with higher controllability than the other FPLEs; however, the dynamic balance is not good because they have only one piston. Unlike single-piston FPLEs, a perfectly balanced design is the main advantage of opposed-piston FPLEs, but those designs make engines complicated. Besides description of various piston types, we also described different linear alternator designs for FPLEs. Namely, we classified linear alternators into three main groups, including linear alternator shapes (flat-type and tubular-type linear alternators), phase structure (single-phase and three-phase linear alternators), and arrangements of magnets (moving- magnet, moving-iron, and moving-coil linear alternators). In a simulation study, flat-type linear alternator is considered to be better than tubular one in efficiency, specific power, output voltage and current;
  • 5. Shafeequr Rahman S.I et al., / Journal of Advanced Engineering Research, 2015, x (x), xxx-xxx Research Article 5 www.jaeronline.com however, it needs to be further examined by both simulation and experiment. For phase structure, much research has shown that three-phase linear alternators are appropriate for high-power FPLEs, whereas single-phase linear alternators are suitable for small power FPLEs. In addition to the designed features, we classified FPLEs by their operating characteristics, such as piston dynamics, combustion, and electric power generation characteristics. For piston dynamics, FPLEs decrease heat transfer loss in the cylinder by increasing piston acceleration, compared with conventional engines. The implementation of springs in FPLEs shows benefits for increasing piston velocity and engine performance. In addition to benefit of piston dynamics, published results showthat the thermal efficiency of FPLEs is higher than that of conventional engines. Furthermore, the simulation results of FPLEs show benefits for reducing temperature-dependent emissions (NO) because the in cylinder gas temperature of FPLEs is generally lower than that of conventional engines. X The variable compression ratio in FPLEs is a great benefit for combustion. By changing the compression ratio, FPLEs can optimize the combustion process and operate with various kinds of fuels and HCCI combustion. To obtain successful HCCI combustion in a free- piston engine, simulation studies have utilized the transition from SI to HCCI combustion. Published results show that the engine performance in HCCI combustion is higher than in SI combustion, while the in-cylinder peak temperature in HCCI combustion is much lower than that in SI combustion, which results in decreasing NO emissions. A free-piston engine can not only be operated as a conventional xinternal combustion engine. It can also be integrated with a linear alternator to generate electric power. The electric power can be optimized by adjusting parameters such as piston assembly mass, ignition timing, equivalence ratio, electrical resistance, and air gap. Much research has shown that a linear alternator with a high efficiency power source is an excellent power-unit candidate for HEVs. With the potential offered by high-efficiency linear alternatorsin FPLEs, we expect integrated systems to be further developed applied in the near future ACKNOWLEDGEMENTS This work was supported by Mr. Vinoth. The authors are grateful to him. REFERENCE [1] Wakabayashi R, Takiguchi M, Shimada T, Mizuno Y, Yamauchi T. The effects of crank ratio and crankshaft offset on piston friction losses.SAE paper2003-010983; 2003. [2] Pescara RP. Motor compressor apparatus. US patent no. 1,657,641; 1928. [3] Farmer HO. Free piston compressor engines. Proc Inst Mech Eng 1947; 156:253–71. [4] Pescara RP. Motorcompressorofthe free piston type. US patent no. 2,241,957; 1941. [5] Ostenberg P. Electric generator. US patent 2362151 A; 1944. [6] Hew WP, Jamaludin J, Tadjuddin M, Nor KM. Fabrication and testing of a linear electric generator for use with a free-piston engine. In: National power and energy conference proceeding. [7] Wang J, West M, Howe D, Parra H, Arshad W. Design and experimental verification of a linear permanent magnet generator for a free-piston energy converter. IEEE Trans Energy Convers 2007; 22:2. [8] Li W,Chau KT. A linear magnetic-geared free-piston generator for range extended electric vehicles. J Asian Electric Vehicles 2010; 8:1. [9] Ding H, Yu X, Li J. Permanent magnetic model design and characteristic analysis of the short-stroke free piston alternator. SAE Int J Fuels Lubr 2012. 2012-01-1610. [10] Xu Z, Chang S. Improved moving coil electric machine for internal combustion linear generator. IEEE Trans Energy Convers 2010; 25:2. [11] Mikalsen R, Roskilly AP. A review of free-piston engine history and application. Appl Therm Eng 2007; 27:2339–52. [12] Cawthorne W, Famouri P, Clark N. Integrated design of linear alternator/engine systemfor HEV auxiliary power unit. In: Electric machines and drives conference [13] Goertz M, Peng L. Free piston engine its application and optimization. SAE paper 2000-01-0996; 2000. [14] Carter D, WechnerE. The free piston power pack: sustainable power for hybrid electric vehicles. SAE paper 2003-01-3277; 2003. [15] Mikalsen R, Jones E, Roskilly AP. Predictive piston motion control in a free piston internal combustion engine. Appl Energy 2010; 87:1722–8. [16] Mikalsen R, Roskilly AP. The control of a free- piston engine generator. Part 1: fundamental analysis. Appl Energy 2010; 87:1273–80.
  • 6. Shafeequr Rahman S.I et al., / Journal of Advanced Engineering Research, 2015, x (x), xxx-xxx Research Article 6 www.jaeronline.com [17] Mikalsen R, Roskilly AP. The control of a free- piston engine generator. Part 2: engine dynamics and piston motion control. Appl Energy 2010; 87:1281–7. [18] Robinson MC, Clark N. Fundamental analysis of spring-varied, free piston Otto engine device. SAE Int J Eng 2014. 2014-01-1099. [19] Kim J, Bae C, Kim G. Simulation on the effect of the combustion parameters on the piston dynamics and engine performance using the Wiebe function in a free piston engine. Appl Energy 2013; 107:446–55. [20] Tian CL, Feng HH, Zuo ZX. Oscillation characteristic of single free piston engine generator. Adv Mater Res 2011;383–390:1873–8. [21] Feng HH, Song Y, Zuo ZX, Shang J, Wang YD, Roskilly AP. Stable operation and electricity generating characteristics of a single-cylinder free piston engine linear generator: simulation and experiments. Energies 2015; 8:765–85. [22] Hung NB, Lim O, Iida N. The effects of key parameters on the transition from SI combustion to HCCI combustion in a two-stroke free piston linear engine. Appl Energy 2015; 137:385–401. [23] Chiang CJ, Yang JL, Lan SY, Shei TW, Chiang WS, Chen BL. Dynamic modelling of SI/HCCI free- piston engine generators.In: 6th IEEE conference on industrial electronics and applications. [24] Li QF, Xiao J, Huang Z. Simulation of a two- stroke free-piston engine for electrical power generation. Energy Fuel 2008; 22:3443–9. [25] Lin J, Xu Z, Chang S, Yin N, Yan Thermodynamic simulation and prototype testing of a four-stroke free-piston engine. J Eng Gas Turbines Power2014; 136:1–8. [26] Li L, Luan Y, Wang Z, Deng J, Wu Z. Simulations of key design parameters and performance optimization for a free-piston engine. SAE paper 2010-01-1105; 2010. [27] Prados MA. Towards a linear engine PhD thesis. Stanford University; 2002. [28] Clark NN, Nandkumar S, Famouri P. Fundamental analysis of a linear two- cylinder internal combustion engine. SAE paper 982692; 1998. [29] Mikalsen R, Roskilly AP. The fuel efficiency and exhaust gas emissions of a low heat rejection free-piston diesel engine. Proc IMech Part A: J Power Energy 2009; 223:379–84. [30] Johnson TA,Leick MT. Experimental evaluation of the free piston engine-linear alternator (FPLA), Sandia report no. SAND2015-2095. Albuquerque,United States: Sandia National Laboratories; 2015. [31] Xu Z, Chang S. Prototype testing and analysis of a novel internal combustion linear generatorintegrated power system.Appl Energy 2010; 87:1342–8. [32] Jia B, Smallbone A, Zuo Z, Feng H, Roskilly AP. Design and simulation of a twoor four-stroke free-piston engine generatorfor range extender applications. Energy Convers Manage 2016; 111:289–98. [33] Goldsborough SS, Blarigan PV. Optimizing the scavenging systemfor a two stroke cycle, free piston engine for high efficiency and low emissions: a computational approach.SAE paper 2003-01-0001; 2003. [34] Bergman M, Fredriksson J, Golovitchev V. CFD- based optimization of a dieselfueled free piston engine prototype for conventionaland HCCI combustion. SAE paper2008-01-2423; 2008. [35] Fredriksson J, Bergman M, Golovitchev V, Denbratt. Modeling the effect of injection schedule change on free piston engine operation. SAE paper 2006-010449; 2006. [36] Bergman M, Golovitchev V. CFD modeling of a two-stroke free piston energy converter using detailed chemistry. SAE paper 2005- 24-074; 2005. [37] Xia H, Pang Y, Grimble. Hybrid modeling and control of a free-piston energy converter. In: Proceedings of the 2006 IEEE international conference on control applications. [38] Mikalsen R, Roskilly AP. A review of free-piston engine history and application. Appl Therm Eng 2007; 27:2339–52. [39] Nagy CT, Clark NN. The linear engine in 2004. SAE paper2005-01-2140; 2005. [40] Kosaka H, Akita T, Moriya K, Goto S, Hotta Y, Umeno T, et al. Development of free piston engine linear generatorsystempart 1 – investigation of fundamental characteristics. SAE paper2014-01-1203; 2014. [41] Berlinger WG, Raab FJ. Free piston engine with electrical power output.US patent no. 6541875 B1; April 1, 2003. [42] Kos J. Free-piston engine without compressor. US patent no. 4,924,956; May 15, 1990. [43] Blarigan PV. Advanced internal combustion electrical generator. In: Proceedings of the 2001 DOE hydrogen program review. p. 1–16. [44] Huang L. An opposed-piston free-piston linear generator development for HEV. SAE paper 2012-01-1021; 2012. [45] Yan H, Wang D, Xu Z. Design and simulation of opposed-piston four-stroke
  • 7. Shafeequr Rahman S.I et al., / Journal of Advanced Engineering Research, 2015, x (x), xxx-xxx Research Article 7 www.jaeronline.com free-piston linear generator. SAE paper 2015-01-1277; 2015. [46] Washko FM, Winchell RA. Free piston combustion engine design analysis and challenges. SAE paper2015-32-0768; 2015. [47] Galitello KA. Two stroke cycle engine. US patent no. 4876991 A; October 31, 1989. [48] Blarigan PV. Free-piston engine. US patent no. 6199519 B1; March 13, 2001. [49] Rinderknecht F. The linear generatoras integral component of an energy converter for electric vehicles. In: European all-wheel drive congress,Graz. [51] Boldea I, Nasar SA. Permanent-magnet linear alternators part 1: fundamental equations. IEEE Trans Aerosp Electron Syst 1987; AES-23:73–8. [52] Hong SK, Choi HY, Lim JW, Lim HJ, Jung HK. Analysis of tubular-type linear generator for free-piston engine. In: International conference on renewable energies and power quality. .