An engine works on dual combustion cycle, the compression ratio being 11 . The pressure at the commencement of combustion is 1 bar and the temperature is 90C. The maximum pressure in the cycle is 50 bar and the constant pressure heat addition continues for 1/20 of the stroke. Calculate the work done per \(\mathrm{kg}\). of air and the ideal thermal efficiency. Assume \(c_{v}=0.718 \mathrm{~kJ} / \mathrm{kg}\) \(K, c_{p}=1.005 \mathrm{~kJ} / \mathrm{kgK}\).

50- 3 bar 1 as 5 04 24 Fig. 7.19