Question

Compare otto cycle with Diesel cycle?

Answer 1

These two cycles can be compared on the basis of either the same compression ratio or the same maximum pressure and temperature.

1 - 2 - 3 - 5 = Otto Cycle,

for the same heat rejection Q₂ the higher the 1 - 2 -4 - 5 = Diesel Cycles, heat given Q_1, the higher is the cycle efficiency.

So from T-S diagram for cycle 1 - 2 - 3 - 5, Q₁ is more than that for 1 - 2 - 7 - 5 (area under the curve represents Q,).

Hence ηOtto > ηDiesel For the same heat rejection by both otto and diesel cycles. Again both can be compared on the basis of same maximum pressure and temperature.

1 - 2 – 3 – 4 = Otto Cycle; Here area under the curve

1 - 2′ - 3 - 4 = Diesel Cycle

1 - 2′ - 3 - 4 is more than 1 - 2 – 3 – 4

So ηdiese l > ηotto; for the same T_max and P_max