1) Air in a piston-cylinder assembly and modeled as an ideal gas undergoes two internally reversible processes in series from state 1, where T1 5 290 K, p1 5 1 bar.
Process 1-2: Compression to p2 5 5 bar during which pV1.19 5 constant.
Process 2-3: Isentropic expansion to p3 5 1 bar.
(a) Sketch the two processes in series on T-s coordinates.
(b) Determine the temperature at state 2, in K.
(c) Determine the net work, in kJ/kg.
2) Air enters an insulated turbine operating at steady state at 8 bar, 11278C and exits at 1.5 bar, 3478C. Neglecting kinetic and potential energy changes and assuming the ideal gas model for the air, determine
(a) the work developed, in kJ per kg of air flowing through the turbine.
(b) whether the expansion is internally reversible, irreversible, or impossible.