Diesel Cycle

The Diesel cycle is an ideal air standard cycle which consists of four processes:

1 to 2: Isentropic compression
2 to 3: Reversible constant pressure heating
3 to 4: Isentropic expansion
4 to 1: Reversible constant volume cooling
By defining the compression ratio, r, as:

and cut-off ratio,

, as:

The thermal efficiency of an Diesel cycle with a perfect gas as working fluid is:

where,
n=

= a constant depending on specific heat capacity