Helium flows steadily through a long insulated duct with a constant cross-sectional area of 100 cm2. At the inlet, the conditions are 300 kPa, 300 K and 10 m/s. A 5 kW internal electrical heater is used to raise the temperature of the gas. At the exit, the pressure drops to 100 kPa due to frictional losses in the duct. Determine
(a) The exit velocity (V2).
(b) The rate of entropy generation (S⋅gen) in the system's universe. Use the PG model.
(c) What-if Scenario: How would the answer in part (b) change if the heater were turned off? (assume the exit pressure to be 100 kPa).