Assume the same tank and conditions as in Problem 15.59. After some flow out, the nozzle flow becomes subsonic. Find the mass in the tank and the mass flow rate out at that instant.
Problem 15.59
A 1-m3 uninsulated tank contains air at 1 MPa, 560 K. The air in the tank is now discharged through a small convergent nozzle to the atmosphere at 100 kPa, while heat transfer from some source keeps the air temperature in the tank at 560 K. The nozzle has an exit area of 2 × 10-5 m2.
a. Find the initial mass flow rate out of the tank.
b. Find the mass flow rate when half of the mass has been discharged.