Q$\mathrm{.}5)$ In an adiabatic turbine steam enters steadily at $1\mathrm{.}8$MPa and $550C$ and leaves at $100$kPa. If the isentropic efficiency of the turbine is $61\mathrm{.}2\%$ and mass flow rate is $3k\frac{g}{s},$ draw the process in $P-h$ diagram and determine

a$)$ Enthalpy and entropy of the steam at the inlet

b$)$ Enthalpy of the water at the exit for the case of isentropic expansion $($h$2$s$).$

c$)$ Actual enthalpy, entropy and temperature of the fluid at the exit.

d$)$ Work produced.

e$)$ Plot the effect of the isentropic efficiency on the work output.

f$)$ Solve the problem using organic fluid R$245$fa

Q$\mathrm{.}6)$ In a turbocharger, exhaust gases enter the turbine at $400C$ and $120$kPa at a rate of $0\mathrm{.}02k\frac{g}{s}$ and leave at $350C.$ Air enters the compressor at $50C$ and $100$kPa and leaves at $130$kPa at a rate of $0\mathrm{.}018k\frac{g}{s}.$ The compressor increases the air pressure with a side effect: It also increases the air temperature, which increases the possibility that a gasoline engine will experience an engine knock. To avoid this, an aftercooler is placed after the compressor to cool the warm air with cold ambient air before it enters the engine cylinders. It is estimated that the aftercooler must decrease the air temperature below $80C$ if knock is to be avoided. The cold ambient air enters the aftercooler at $30C$ and leaves at $40C.$ Disregarding any frictional losses in the turbine and the compressor and treating the exhaust gases as air, determine

a$)$ the temperature of the air at the compressor outlet and

b$)$ the minimum volume flow rate of ambient air required to avoid knock.

c$)$ Solve the problem taking the isentropic efficiencies of the compressor and turbine as $0\mathrm{.}85.$