Air Standard Efficiency of Ideal Otto Cycle

Question

How the modification in the compression ratio affects the air standard efficiency of an Ideal Otto Cycle?

Answer 1

The expression for the air standard efficiency of an Otto cycle is:

η_Otto = 1-(1/R^y-1 )

Where,

R – Compression ratio
γ – Ratio of specific heats

As per the above  expression, the efficiency  rises  with  the  rise  in  the  value  of  R that is compression  ratio,  means that the efficiency could  be enhanced,  simply by increasing the compression ratio. But this increase in the compression ratio also has a significant extent of increase due to various practical difficulties.