Introduction of I.C.Engine

 Definition of Engine :

An engine is a device which transforms one form of energy into another form .

Normally ,most of the engines convert thermal energy into mechanical work and therefore they are called heat engines

Definition of Heat Engine:

Heat engine is a device which transforms chemical energy of fuel into thermal energy and utilizes this thermal energy to perform useful work. Thus thermal energy is converted to mechanical energy in a heat engine.

Heat engines can be classified into two categories :

1. I.C.Engines

2. E.C.Engines

I.C. - Internal combustion

E.C. - External combustion

I.C. or E.C. are of two types : 

1. Rotary engines

2. Reciprocating engines

External combustion engines are those in which combustion takes place out- side the engine whereas in internal combustion engines combustion take  place within the engine.

There are two types of engines : 

1. Spark ignition (SI)

2. Compression ignition (CI)

Engine Components :

1. Cylinder Block

2. Cylinder

3. Piston 

4. Combustion chamber

5. Inlet Manifold

6. Exhaust Manifold

7. Inlet and Exhaust valves

8. Spark plug

9. Connecting Rod

10. Crankshaft

11. Piston Rings

12. Gudgeon pin 

13. Camshaft

14. Cams

15. Fly Wheel 

Nomenclature:

1. Cylinder Bore (d)

2. Piston Area (A)

3. Stroke (L)

4. Stroke to Bore Ratio (L/d)

5. Dead Centre

6. Displacement or swept volume (Vs)

7. Cubic capacity or engine capacity (cc)

8. Clearence volume (Vc)

9. Compression Ratio (r)

There are two dead centres in engine .

1. Top Dead Centre (TDC)

2. Bottom Dead Centre ( BDC)