Question

Need help with Thermodynamics Homework. WILL RATE HIGH! Thank you! Please answer them all for high rate

1. Carbon Oxide (CO) initially occupying 2.9 m³ at 7.4 bar, 246.85°C undergoes an internally reversible expansion during which pV^1.4 = constant to a final state where the temperature is 36.85°C. Assuming the ideal gas model, determine the entropy change, in Joules/K.

2. Water at 10 bar, 240°C enters a turbine operating at steady state and exits at 4 bar. Stray heat transfer and kinetic and potential energy effects are negligible. A hard-to-read data sheet indicates that the quality at the turbine exit is 63%. Determine the entropy production in Joules/kg. K.

3. A mass of 7.6 kg of water contained in a piston–cylinder assembly expand from an initial state where T₁ = 578°C, p₁ = 700 kPa to a final state where T₂ = 218°C, p₂ = 300 kPa, with no significant effects of kinetic and potential energy. It is claimed that the water undergoes an adiabatic process between these states, while developing work. Evaluate entropy production in Joules/k.

4. At steady state, air at 200 kPa, 51.85°C and a mass flow rate of 4.08 kg/s enters an insulated duct having differing inlet and exit cross-sectional areas. At the duct exit, the pressure of the air is 100 kPa, the temperature is 82°C, the velocity is 255 m/s, and the cross-sectional area is 2 x 10^-3 m². Assuming the ideal gas model, determine the rate of entropy production within the duct, in W/K.

Answer 1

It is asked to find the entropy change and generated in all the processes. For a process which is adiabatic ( no heat transfer with surrounding) , the entropy change is same as the entropy generated.