turbocharger

The gaseous combustion products in an internal combustion engine are at a pressure of 8 bar and a temperature of 820°C (1093.15K). Without a turbocharger, the gases are exhausted at this state into the environment. With a turbocharger, the gases are reduced to a temperature of 187°C (460.15K) at the exhaust. Assume that the heat loss ratio Q? 1/Q? s is 25% without a turbocharger and only 20% with a turbocharger, and that Ts = 900°C (1173.15K). Calculate the value of rII for the two cases. The environmental temperature and pressure are T0 = 15°C (288.15K) and P0 = 1atm.