Answer:
[tex]r= \dfrac{V_1}{V_2}[/tex]
[tex]\eta =1-\dfrac{1}{r^{\gamma-1}}[/tex]
Explanation:
Compression ratio:
Compression ratio is the ratio of volume in the cylinder.Generally it is denoted by r.
The compression ratio for Otto cycle is about 8 to 12.But the compression ratio of diesel engine is about 14 to 25.
So from the Otto cycle compression ratio can be define as
[tex]r= \dfrac{V_1}{V_2}[/tex]
As we know that efficiency defines as the ratio of work out to the heat input.In the Otto cycle the efficiency is given as in terms of compression ratio r as
[tex]\eta =1-\dfrac{1}{r^{\gamma-1}}[/tex]
Where γ is the heat capacity ratio.
