b. Air flows in a converging-diverging nozzle Throat from stagnation conditions at P, - 500 kPa To ME Po and T. = 400 K as shown in Fig.2. The exit static pressure is 450 kPa, and the throat and exit areas are 0.01 m? and 0.015 m? Supersonie nozzle Ag Po respectively. Assuming isentropic flow, determine the Mach number, ME at exit PE and the mass flow rate h when the flow is supersonic in the divergence section of the (Ma, = 1) duct. Fig.2 (Take for air, K=1.4, and R= 287 m?/s?.K)

4. It is important to remember that the isentropic relations and normal shock relationsare monotonic with Mach number and can be inverted. To illustrate this, consider thefollowing problems, (c) If the temperature jumps from 0 Celsius ahead of a shock to 200 Celsius behinda shock, what is the shock Mach number?(d) If the velocity behind a Mach 5 shock wave is 200 m/s, what is the upstreamvelocity?

Example 3 Helium expands in a nozzle at from 1.2 MPa, 600 K and negligible velocity to 0.1 MPa. Khelium = 1.6 and Cp Calculate the throat and exit areas for a mass flow rate of 0.1 kg/s, assuming the nozzle (a) is isentropic and Why must this nozzle be converging-diverging nozzle?

Gas dynamics