Internal Combustion Engines

SUBMITTED TO: SUBMITTED BY: Mohit Yadav Sir

Deepak Sahu Susheel

Kushwaha Nishant

Kesharwani

Internal Combustion Engines

types of heat engines

external combustion

internal combustion

steam engines

turbines

Stirling engine

Otto engine

Diesel engine

Vankel engine

CLASSIFICATION

TurboshaftAll shaft work to drive propeller,

generator, rotor (helicopter)

TurbofanPart shaft, part jet -"ducted propeller"

TurbojetAll jet except for work needed to

drive compressor

Gas TurbineUses compressor and turbine,

not piston-cylinder

RamjetNo compressor or turbine

Use high Mach no. ram effect for compression

Solid fuelFuel and oxidant are premixed

and put inside combustion chamber

Liquid fuelFuel and oxidant are initially separatedand pumped into combustion chamber

RocketCarries both fuel and oxidantJet power only, no shaft work

Steady

Two-strokeOne complete thermodynamic cycle

per revolution of engine

Four-strokeOne complete thermodynamic cycle

per two revolutions of engine

Premixed-chargeFuel and air are mixed before/during compression

Usually ignited with spark after compression

Two-strokeOne complete thermodynamic cycle

per revolution of engine

Four-strokeOne complete thermodynamic cycle

per two revolutions of engine

Non-premixed chargeOnly air is compressed,

fuel is injected into cylinder after compression

Non-steady

Internal Combustion Engines

Internal Combustion Engines

The internal combustion engine is an engine in which

the combustion of fuel-oxidizer mixture occurs in a

confined spaceapplied in: automotiverail transportationpower generationshipsaviationgarden appliances

Internal Combustion Engines

Internal Combustion Engines – Carnot cycle -

Diesel Cycle

Internal Combustion Engines – two stroke -

1. Power / Exhaust 2. Intake / Compression

a. ignitionb. piston moves downward

compressing fuel-air mixture in the crankcase

c. exhaust port opens

a. inlet port opensb. compressed fuel-air mixture

rushes into the cylinderc. piston upward movement

provides further compression

Internal Combustion Engines – two stroke -

Advantages:• lack of valves, which simplifies

construction and lowers weight• fire once every revolution, which gives a

significant power boost • can work in any orientation• good power to weight ratio

Drawbacks:• lack of a dedicated lubrication system

makes the engine to wear faster. • necessity of oil addition into the fuel • low efficiency • produce a lot of pollution

Internal Combustion Engines – four stroke -

starting position

a. piston starts moving downb. intake valve opensc. air-fuel mixture gets in

1. intake

a. piston moves upb. both valves closedc. air-fuel mixture gets compressed

2. compression

Internal Combustion Engines – four stroke -

ignition

a. air-fuel mixture explodes driving the piston down

3. power

a. piston moves up b. exhaust valve opens c. exhaust leaves the cylinder

4. exhaust

Intake (piston moving down, intake valve open, exhaust valve closed)

Compression (piston moving up, both valves closed)

Expansion (piston moving down, both valves closed)

Exhaust (piston moving up, intake valve closed, exhaust valve open)

Internal Combustion Engines – four stroke -

Advantages:• dedicated lubrication system makes to

engine more wear resistant• better efficiency that 2-stroke engine • no oil in the fuel – less pollution

Drawbacks:• complicated constriction • should work in horizontal position due to

lubrication

Internal Combustion Engines – Diesel -

air intake

compression

fuel injection

combustion

exhaust

exhaust /intake

Internal Combustion Engines – Diesel -

Advantages:• self ignition (without electrical spark plug)• better efficiency• reliability• higher durability• supplied with worse fuels

Drawbacks:• more NOx production • more expensive production• more weight • louder• lower revolutions

Internal Combustion Engines – multi-cylinder -

Cylinder layouts

inline

V

flat