1. A REVIEW ON FREE PISTON LINEAR
ENGINE AND ITS CONTROL SYSTEM
BY:
SHAFEEQUR RAHMAN S.I
SURYA KANDHASWAMYT
Dr P. GOPAL
Department of Automobile Engineering
ANNA UNIVERSITY
BHARADHIDASAN INSTITUTE OF TECHNOLOGY(BIT) CAMPUS
TIRUCHIRAPPALLI-620024
3. Introduction
• FPLE is nothing but an engine works without crankshaft
• Instead of crankshaft , here an turbine and linear alternator is used to
convert the rotary motion into reciprocatory motion
• This crank less engine reduce the losses due the crankshaft
5. 1. It includes a single-piston, cylinder, and rebound
device
2.The single-piston FPLE is mechanically simple with
high controllability when compared to other FPLEs
1. It consists of two combustion chamber and a dual-piston
2.This engine eliminates the need for a rebound device, as the working piston
provides the work to drive the compression process
3. In the other cylinder, which allows a simple and more compact device with
higher power to weight ratio
1. It consists of two single piston units with a single combustion
Chamber
2. Its pistons are synchronized by mechanical linkages to eliminate
mechanical vibration, which is not found on any other linear
engines
3. A shared combustion chamber also reduces heat losses.
PISTON CONFIGURATION
Single piston.
Dual piston.
Opposed
piston.
6. Experimental systems
• Single piston engine with linear alternator
• Opposed piston engine setup
• Dual piston engine setup
8. Applications of FPLE
• 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 show that the
thermal efficiency of FPLEs is higher than that of conventional engines.
9. Applications of FPLE (cont…)
• 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.
• 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.
• A free-piston engine can not only be operated as a conventional internal 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.
10. Conclusion
• In this paper, we have reviewed 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.
• 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 alternators in FPLEs, we expect integrated systems to be further developed and
applied in the near future.
11. References
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