1. Advancement of IC Engine
SEMINAR REPORT
Guidance under
Mr. D. Sanyal
(Specialized Area:-Theory of Machine,
Mechanical Science, Engineering Drawing)
Presented by:- Prakash Giri
Kalyani Govt. Engineering College
Date :- 20/11/15 Mechanical Engineering
3rd Yr, Roll No- 31
2. What is an IC engine?
A device for producing motive power
from heat called heat engine.
There are two types of heat engine
available,
Internal combustion engine.(ICE)
External combustion engine.(ECE)
An internal combustion engine
(ICE) is a heat engine where the
combustion of a fuel occurs with an
oxidizer (usually air) in a combustion
chamber that is an integral part of the
working fluid flow circuit.
3. Introduction to IC engines
Invented in early 1680.
First attempt by Christian Huygens.
First commercial success by Étienne Lenoir in 1859.
First modern IC engine proposed by Siegfried Marcus
in 1864.
Converts heat energy produced by burning of fuel to
mechanical output.
Basically consists of a piston-cylinder arrangement.
The expansion of combustion fuel due to the heat
produced moves the piston inside the cylinder.
4. Classification of IC engines
Two main classifications:
Based on combustion
Spark Ignition [SI engines] (Eg: Petrol Engine)
Compression Ignition [CI engines] (Eg: Diesel
Engine)
Based on Number of strokes
Two stroke
Four Stroke
Six Stroke
5. Major areas of advancement
The vision behind evolving of IC engine was to extract
maximum power from the fuel while reducing emissions
and pollution from the engine.
The main areas of advancement are:
Engine Design
Material Selection
Timing Controls
Fuel Injection And Combustion
Pollution control
Use of non-conventional or advanced fuels
The advances moves almost parallel and most companies
have their own versions of the advances discussed here.
6. Our Goals for advancement
To get more power from engine
Less weight to power ratio
Lower weight to torque ratio
Less complexity in engine deign
Better fuel economy
Less pollution
Lower cost of production
Higher safety
7. Engine Design
The early designs involved a single cylinder. This
caused a large amount of fluctuations in power
output.
So more number of cylinders were added to reduce
output fluctuations and size of engine
There are four types of engine designs used.
Inline
V Type
Flat Type
Radial Engines
9. Material selection
When selecting materials for engine, following
factors are considered
Weight of material
Melting point
Coefficient of expansion
Heat transmission power
Vibration and sound damping
Fatigue resistance
Strength at elevated temperature
The main metals used in engine manufacture are
Grey Cast Iron
Aluminium alloy
Magnesium alloy
10. Use of Sodium in engines
A part of engine is hollowed and is filled with sodium
When temperature of the part becomes 1600C sodium
melts
This molten state has better heat transfer that solid
metal
Sodium is mainly used in:
Sodium Valves (Exhaust Valves)
Piston Skirts
11. Timing controls
The Efficiency of engine is decided by the timing of its
sequential operation.
Timing of inlet and exhaust valves
Timing of the spark in SI engines
Timing of fuel injection in CI engines
Sequential operation of each cylinders in multi cylinder engine
In normal cases these timings are a design parameter
set at time of manufacture.
The goal of timing control is to change the timings of
engine while its working.
12. Variable Valve Timing (VVT)
At low rpm, the timing is adjusted
for maximum efficiency.
At high rpm, the valve remains
opened is reduced while increasing
the opening size.
This helps to pump more charge to
cylinder without creating
backpressure or scavenging.
An electronic system uses a
microcontroller to adjust the
solenoid valve.
13. Continued.
In a mechanical system, the input from crank is given
to a gear which is locked to the cam using a pin.
When adjustment is needed, the pin is removed
magnetically and a stepper motor adjusts the cam.
Used in many cars in various names
BMW Valvetronic, VANOS
Fiat Twin Cam VIS
General Motors VVT, DCVCP
Honda VTEC, i-VTEC
Porsche VarioCam
14. Active Valve Train
In active valve train, there will be two cams designed
for specific road conditions.
When the microprocessor detects a rough terrain, the
cam used will be the one for more power.
But during cruising, the cam is switched to a low
power, high efficient cam using a cam tapper.
Introduced first by Lotus Motors and later developed
by Nissan Motors.
15. Cylinder Deactivation
Cylinder deactivation is a derived form of active cam
switching.
In this method, while cruising a part of cylinders are
switched off by switching to a cam without lobes.
This method leads to
Lesser fuel consumption
Less heat generation
Less power lost in managing other cylinders
This is mostly employed in V Type Engines.
16. Continued.
The cylinder is deactivated by
Keeping the inlet valve closed so that there is no fuel
flow
Keeping the exhaust valve open so there is no work done
in compression.
Some Companies using cylinder deactivation are
General Motors V8-6-4 (Cadillac)
General Motors Active Fuel Management
DaimlerChrysler Active Cylinder Control (ACC) (for Mercedes-
Benz)
Honda Variable Cylinder Management (VCM)
17. Fuels and Fuel Injection
The fuels and its input to the engine highly influences
the emissions from the engines.
In SI engines a air-fuel mixture called charge is
introduced to the cylinder before compression
In CI engines the fuel is injected after the compression
stroke to the cylinder. This helps in attaining higher
compression ratios.
In SI engines it is not possible because there is a
chance that the fuel may burn before hand.
18. Direct Injection
With direct injection, the advantages of
CI engines can be obtained in SI
engines also.
In direct injection, first the air is filled
in the cylinder. Then half way through
the compression stroke, a small amount
of fuel is injected to the cylinder to
create a lean mixture.
So In place of the carburettor, therefore,
the MPEFI (multi point electronic fuel
injection) system is used, assuring
proper air fuel ratio to the engine by
electrically injecting fuel in accordance
with various driving condition.
19. Continued.
At the end of compression, just before the spark the rest of
fuel is injected to the head of spark plug.
The burning of fuel occurs in a stratified pattern near the
spark plug.
Direct injection has many advantages such as
No need of carburetor
Easy design of manifold
Better compression is achievable
No case of knocking in engines
Lower NOx emissions
Due to stratified combustion leaner mixture can be used
which reduces the fuel consumption.
20. Superchargers
Consists of a compressor coupled to the
engine using a belt.
The output is directly connected to the
engine.
As the engine rotates, the air is sucked in
and compressed which is then fed to the
cylinders.
Increases the amount of oxygen given to
engine thus helps in better burning.
Is a must in aircrafts flying at high
altitudes were air is less dense.
21. Turbochargers
Is a derived form of supercharger
Consists of a turbine and a
compressor coupled in a shaft.
Instead of using the power from
engine to turn the compressor, the
exhaust is used to turn the turbine
which rotates the compressor.
Turbochargers can only act at high
velocity exhaust so they need some
time to start up in cold start. This
time is called as turbo lag.
22. Six Stroke Engines
The invention of six stroke engines was for the
following reasons:
Less weight to power ratio
Less scavenging
Less moving parts
More power and fuel economy
Obtain freedom in designing
Better cooling
Six stroke engines are developed in two different ways
23. Air/Water injection to Cylinder
In this method air or water is injected to the cylinder at
the end of exhaust stroke.
The fluid absorbs the heat and expands providing
another power stroke. An exhaust stroke is provided to
removed the fluid from cylinder.
Three recognized names in this section are:
Bajulaz six stroke engine (Preheating of air)
Velozeta six stroke engine (Injection of air)
Crower six stroke engine (Injection of water)
24. Opposed Piston Engines
This model uses two pistons working
in a cylinder.
The pistons are used to open and
close ports just like a two stroke
engine.
The working of opposed pistons
provide better compression.
The pistons have either a change in
speed or have a phase shift between
them.
Some engines in this section are:
Beare Head Engine
M4+2 engine
25. Air Pollution:
Reasons:
• Incomplete combustion of carbonaceous fuel
• Evaporation Loss
• Exhaust Emission
• Low Quality Fuel
• Revolution per minute
27. How to reduce Air Pollution:
o Increasing amount of air reduces
incomplete combustion projects
o Use of appropriate A/F ratio
o Engine should be maintained
properly.
o A catalytic converter is a device
which is placed in vehicle exhaust
system to reduce HC & CO by
oxidizing catalyst & NO by Reducing
agent
o Rhodium is best Catalyst to control
NOX keeping A/F ration within 14.6:1
to 14.7:1