Question

The efficiency of an Otto cycle is 60 % and y = 1.5
, the compression ratio is *​

Answer 1

Given:

efficiency of Otto cycle = 60%

y = 1.5 (specific heat ratio)

To Find:

compression ratio=r =?

Solution:

We know that the relation between the efficiency of otto cycle and compression ratio can be represented as shown below,

efficiency of Otto cycle = $1 - \dfrac{1}{r^{y-1} }$

now we have efficiency, specific heat ratio, on putting vaues in above equation

$\dfrac{60}{100} = 1- \dfrac{1}{r^{1.5 - 1} }$

$0.6 = 1- \dfrac{1}{r^{0.5} }$

$0.4 = \dfrac{1}{r^{0.5} }$

${r^{0.5} } = \dfrac{1}{0.4}$

r = 6.25

Thus, the compression ratio is 6.25