One kg of air initially at 0.7 MPa, 20°C changes to 0.35 MPa, 60°C by the three reversible non-flow processes, as shown in Figure. Process 1: a-2consists of a constant pressure expansion followed by a constant volume cooling, process 1: b-2 an isothermal expansion followed by a constant pressure expansion, and process 1: c-2 an adiabatic
Expansion followed by a constant volume heating. Determine the change of internal energy, enthalpy, and entropy for each process, and find the work transfer and heat transfer for each process. Take cp= 1.005 and cv= 0.718 kJ/kg K and assume the specific heats to be constant. Also assume for air pv = 0.287 T, where p is the pressure in kPa, v the specific volume in m3/kg, and T the temperature in K.