Question

An engine of 250 mm bore and 375 mm stroke works on otto cycle. The clearance volume is 0.00263 m³. The initial pressure and temperature are 1 bar and 50ºC. If the maximum pressure is limited to 25 bar. Find (1) The air standard efficiency of the cycle. (2) The mean effective pressure for the cycle.

Answer 1

Given that: 

Bore diameter d = 250mm 

Stroke length L = 375mm 

Clearance volume VC = 0.00263 m³ 

Initial pressure P₁ = 1bar 

Initial temperature P₃ = 25 bar 

We know that, swept volume

∴ The air standard efficiency for Otto cycle is given by