A compression$-$ignition engine working on the Dual cycle takes in two$-$fifths of its total

heat supply at constant volume and the remaining at constant pressure. Calculate:

The pressure and temperature at the five cardinal points of the cycle.

$(8$ marks$)$

Pressure ratio and cut$-$off ratio.

The ideal thermal effieiency of the cycle.

Given: Compression ratio $=15,$ Maximum pressure in the cycle $=45$ bar, Air intake at

$1\mathrm{.}8$ bar and $25C,C_p=1\mathrm{.}004k\frac{J}{k}gK,C_v=0\mathrm{.}717k\frac{J}{k}gK$

Fill the answers in the following tables: