1. A DVANCE I.C. E NGINES TAE-II P OWER P OINT P RESENTATION Prepared By- Adneya S. Deodhar Mech.6 th Semester Sec-A Roll No- 05 Name Of Topic: Comparison Between SI and CI Engines

2. H EAT E NGINE Definition: “Heat engine is a device which transforms the chemical energy of fuel into thermal energy and utilizes this thermal energy to perform useful work. ” Thus using heat engine thermal energy is converted to mechanical energy in a heat engine. Heat engines classification is given below 1. Internal Combustion Engines (IC Engines) A. Rotary IC Engines i. Open Cycle Gas Turbine ii. Wankel Engine B. Reciprocating IC Engines i. Gasoline Engine (SI Engine) ii. Diesel Engine (CI Engine) 2. External Combustion Engines (EC Engines) A. Rotary EC Engines i. Steam Turbine ii. Closed Cycle Gas Turbine B. Reciprocating EC Engines i. Steam Engine ii. Stirling Engine

3. S PARK I GNITION E NGINE (SI E NGINE ) The credit of invention of SI engine goes to Nicolaus A. Otto(1876). Therefore SI engine is also called as Otto Engine Four Stroke SI Engine In a four stroke engine the cycle of operation is completed in four strokes of piston or two revolutions of crank shaft. During four strokes there are five events to be completed viz. suction, compression, combustion, expansion and exhaust. Each stroke consist of 180 degree of crankshaft rotation. The cycle of operation for an ideal four stroke SI engine consist of following strokes 1.Suction or intake stroke 2.Compression stroke 3.Expansion or power stroke 4.Exhaust stroke Cycle of operation is shown in Fig.

4. Working Of Four Stroke SI engine

5. I DEAL & A CTUAL PV D IAGRAM F OR 4 S TROKE SI E NGINE Ideal PV diag. Actual PV diag.

6. S ECTIONAL V IEW O F SI E NGINE

7. A NIMATION S HOWING W ORKING O F SI E NGINE

8. C OMPRESSION I GNITION E NGINE (CI E NGINE ) The credit of invention of CI engine goes to Rudolf Diesel (1892). Four Stroke CI Engine The four stroke CI Engine is similar to the four stroke SI engine but it operates at much higher compression ratio. The compression ratio for SI engine is between 6 to 10 while for CI engine it is between 16 to 20. Working operation of CI engine is shown in fig.

9. W ORKING O F F OUR S TROKE CI E NGINE

10. F OUR S TROKE CI E NGINE

11. PV D IAGRAM F OR F OUR S TROKE CI E NGINE

12. A NIMATION S HOWING W ORKING OF CI E NGINE