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ADVANCES IN IC ENGINES SANKAR RAM T. , MIDHUN ANTONY JOSEPH Jyothi engineering college, Cheruthuruthy, Thrissur.
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Advances in ic engines

Aug 11, 2014

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Sankar Ram

 
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Page 1: Advances in ic engines

ADVANCES IN IC ENGINESSANKAR RAM T. , MIDHUN ANTONY JOSEPHJyothi engineering college, Cheruthuruthy, Thrissur.

Page 2: Advances in ic engines

Introduction to IC engines Invented in early 1680 First attempt by Christian Huygens Converts heat energy produced by

burning of fuel to mechanical output. Basically consists of a piston-cylinder

arrangement. The expansion of air due to the heat

produced moves the piston inside the cylinder.

Page 3: Advances in ic engines

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

Page 4: Advances in ic engines

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

The advances moves almost parallel and most companies have their own versions of the advances discussed here.

Page 5: Advances in ic engines

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

Page 6: Advances in ic engines

Engine Design

Inline Engine

V Type Engine

Flat Engine

Radial Engine

Page 7: Advances in ic engines

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

The main metals used in engine manufacture are

Grey Cast Iron Aluminium Magnesium

Page 8: Advances in ic engines

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

Page 9: Advances in ic engines

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.

Page 10: Advances in ic engines

Variable Valve Timing (VVT) At low rpm, the timing is adjusted for

maximum efficiency. At high rpm, time the valve remains

opened is reduced while increasing the opening size.

This helps to pump more charge to cylinder without creating backpressure or scavenching.

An electronic system uses a microcontroller to adjust the solenoid valve.

Page 11: Advances in ic engines

Variable Valve Timing (VVT) 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 namesBMW Valvetronic, VANOSFiat Twin Cam VISGeneral Motors VVT, DCVCPHonda VTEC, i-VTECPorsche VarioCam

Page 12: Advances in ic engines

Variable Valve Timing (VVT)

Page 13: Advances in ic engines

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.

Page 14: Advances in ic engines

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 is successful because of following Lesser fuel consumption Less heat generation Less power lost in managing other cylinders

This is mostly employed in V Type Engines.

Page 15: Advances in ic engines

Cylinder Deactivation 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)

Page 16: Advances in ic engines

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.

Page 17: Advances in ic engines

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.

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.

Page 18: Advances in ic engines

Direct Injection 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.

Page 19: Advances in ic engines

Direct Injection

Page 20: Advances in ic engines

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.

Page 21: Advances in ic engines

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.

Page 22: Advances in ic engines

Six Stroke Engines The invention of six stroke engines was

for the following reasons:Less weight to power ratioLess scavenchingLess moving partsMore power and fuel economyObtain freedom in designingBetter cooling

Six stroke engines are developed in two different ways

Page 23: Advances in ic engines

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)

Page 24: Advances in ic engines

Opposed Piston Engines This model uses two pistons working in

and 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

Page 25: Advances in ic engines

References en.wikipedia.org www.greencar.com www.mitsubishi-motors.com www.bmw.com/com/en/insights Elements of IC Engines, Rogowsky,

Tata McGraw hill Internal Combustion Engines,

Mathur & Metha, Vol I&II Pergamon Press

Page 26: Advances in ic engines

Thank You For Your Time !

Questions ?