Calculate mean effective pressure of engine:

A 4 stroke diesel engine is having length of 20 cm and diameter of 16 cm. The engine is generating indicated power of 25 KW when it is running at 2500 RPM. Find mean effective pressure of engine.              

Sol.: Length or stroke = 20 cm = 0.2 m

Diameter or Bore = 16 cm = 0.16 m

Indicating power = 25 KW

Speed = 2500 RPM

Mean effective pressure = ?

K = 1

Indicated power = P_ip  = (P_mef.L.A.N.K)/60

Where N = N/2  = 1250 RPM (for four stroke engine)

25 × 103 = {P_mef  × 0.2 × (  /4)(0.16)2  × 1250 × 1}/60

P_mef = 298.415KN/m²                                                                                                .......ANS