Question

An ideal Otto cycle has a compression ratio of 9. Using constant specific heats at room  temperature, determine the thermal efficiency of this cycle and the rate of heat input if the  cycle is to produce 60 kW of power

Answer 1

Solution;

Thermal efficiency is;

$\eta_{thermal}=1-(\frac{V_2}{V_1})^{k-1}$

Given;

Compression ratio;

$\frac{V_1}{V_2}=8$

$k=1.4$

We calculate the thermal efficiency as;

$\eta_{thermal}=1-(\frac18)^{1.4-1}=0.5647$