Question

One kg of air at 100 kPa is mixed with one kg air at 200 kPa, both at 300 K, in a rigid insulated tank. Find the final state (P, T) and the entropy generation in the process.

Answer 1

C.V. All the air. Energy

Eq.: U2 – U1 = 0 – 0

Entropy Eq.: S2 – S1 = 0 + 1S2 gen

Process Eqs.: V = C; W = 0, Q = 0

States A1, B1: uA1 = uB1