Nitrogen (N₂) enters a well-insulated diffuser operating at steady state at 0.656 bar, 275 K with a velocity of 282 m/s. The inlet area is 4.8 x 103 m². At the diffuser exit, the pressure is 0.9 bar and the velocity is 80 m/s. The nitrogen behaves as an ideal gas with k = 1.4. (a) Determine the exit temperature, K, and the exit area, in m². (b) For a control volume enclosing the diffuser determine the rate of entropy production, in kW/K.

for steam, the specific ideal gas constant = 461.5 J/kg K A closed system is comprised of pure water substance initially at a temperature of 500 oC and a pressure of 20 MPa (state 1). The system undergoes an isochoric process whereby its pressure drops to 0.1 Mpa (state 2). Sketch the process on a Temperature-specific entropy plot, showing the lines of constant pressure which pass through steps 1 and 2.

9. thermodynamics

letter d

Figure shows data for a portion of the ducting in ventilation system operating at steady state. The ducts are well insulated and the pressure is very nearly 1 bar throughout. Assuming the ideal gas model for air with Cp  = 1 kJ/kg · K. and ignoring kinetic and potential energy effects, determine: (a) the temperature of the air at the exit, in °C. (b) the exit diameter, in m. (c) the rate of entropy production within the duct, in kJ/min.