# 1 problem on Otto and Diesel cycle as a function of compression ratio

1)

A simplified analysis of the processes occurring in a spark-ignition internal

combustion engine is described by the cold air-standard Otto cycle. The

processes in the compression ignition engine are described by the Diesel cycle.

The purpose of this problem is to compare the Otto and Diesel cycle as a function

of compression ratio.

a.) Calculate and plot the thermal efficiency and mean effective pressure for a

cold air standard Otto cycle for compression ratios between 5 and 35 with a

maximum cycle temperature of 2,500 K. Assume that the state of the air

before compression is 300 K, 1 bar.

b.) Calculate and plot the thermal efficiency and mean effective pressure for a

cold air standard Diesel cycle for compression ratios between 5 and 35 with a

maximum cycle temperature of 2,500 K. Assume that the state of the air

before compression is 300 K, 1 bar.

c.) What conclusions can you draw from your plots?