Question

What is the formula for compression (rk) ratio of the otto cycle?

Answer 1

Adding 1 point of compression (e.g., 5.0-1 becomes 6.0-1, a change of +20% in ratio, increases efficiency by 7.79%), is more effective than the same percentage increase beginning with a higher ratio (10.0-1 becomes 12.0-1, also +20%, but only increases efficiency by 4.65%). 

Answer 2

THE FORMULA FOR COMRESSION (rk) RATIO PG OTTO CYCLE IS   rk=COMPRESSION RATIO =Vmax/Vmin.

Explanation:

• otto cycle describes us about the thermal efficiency using compression ratio.
• where k= cp/cv.
• This compression ratio is basically in between 6 to 12 of otto cycle and 16 to 25 of Diesel cycle.
• the compression ignition engine working on the ideal dual combustion cycle has a compression ratio of 16:1. The pressure and temperature at the beginning of compression are 98 kN/m2 and 30°C respectively.