Compare otto cycle with Diesel cycle:
Sol.: These two cycles can be compared on the basis of either the same compression ratio or the same maximum pressure and temperature.
![1413_Compare otto cycle with Diesel cycle.png](https://www.expertsmind.com/CMSImages/1413_Compare otto cycle with Diesel cycle.png)
1 - 2 - 3 - 5 = Otto Cycle,
for the identical heat rejection Q2 the higher the
1 - 2 -4 - 5 = Diesel Cycles, heat given Q1,
the higher is cycle efficiency.
So from T-S figure for cycle 1 - 2 - 3 - 5, Q1 is more than that for 1 - 2 - 7 - 5 (area under curve represents Q,).
Hence ηOtto > ηDiesel
For same heat rejection by otto and diesel cycles both.
Both can be compared on the basis of same maximum pressure and temperature.
1 - 2 - 3 - 4 = Otto Cycle; Here area under curve
1 - 2 - 3 - 4 = Diesel Cycle
1 - 2 - 3 - 4 is more than 1 - 2 - 3 - 4
So diese l > otto; for the same Tmax and Pmax