Question

Nozzles and diffusers are used in applications as sma micro-thrusters (millimeters in diameter) to full-scale wind tunnels. One example of the latter is the NASA Icing Research Tunnel (https: //ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940018618.pdf) shown below. The tunnel test section is a 6 × 8 ft (2.75 × 3.65 m) rectangle that serves as the inlet of a diffuser. The diffuser exit is 13.6 × 16.6 ft (4.14 × 5.05 rn). Test section air flow velocities (at the diffuser inlet) range from 50 to 300 mph (22.4 to 134 m/s) with the pressure being fixed at 1 bar. Assume the inlet air temperature is 68 °F (20°C), that the air density does not change significantly through the diffuser and the diffuser is adiabatic (a) Calculate the air mass flow rates for the 50 and 300 mph cases. Report your answer in kg/s (b) Determie the diffuser exit velocities for those same two cases. (c) Compute the exit temperature and pressure for both the cases. d) The NASA Icing Research Tunnel of HW-14 has a heat exchanger used to cool air to temperatures as low as -35°C. The heat exchanger refrigerating capacity is 2100 ton (7.39 MW). Assume a test section target temperature of -35°C and test section velocities of 50 and 300 mph, along with a fixed test section pressure of 1 bar. Compute the maximum air temperature at the heat exchanger inlet. Report your answers in °C. (Molecular weight of air is 28.97 kg/kmol) Tuming 5000-hp fan 2100-ton 300 mph test varichron drive Baiance chamber cing prays Survey Come Model ocess door Spray bar room Air lock FOre 1 view of long Research Tunnel, sho·ard control non, showing mner e survey

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