MAE 112 PROPULSION MIDQUARTER EXAM March 12, 2004 Do all three problems in one-hundred-and-ten minutes. Books, notes and calculators can be used. 1. Consider a turbine stage that has a polytropic efficiency of 0.98 for the stator (nozzle) and for the rotor flow. 100 % of the total static enthalpy drop through the stage occurs in the stator portion. The initial and final velocities for the stage are axial and have no swirl (tangential component). Assume that only the tangential component of velocity changes through the stator (nozzle) portion. The flow has γ = 1.25 and c p = 0.30 Btu/1bm ° R; the incoming flow has a static temperature of 2300 ° R, a static pressure of 25 atmospheres, and a velocity of 200 ft/sec. The flow exiting the stage has a temperature of 1700 ° R. (a) What are the enthalpy drop and pressure drop across the stator? (b) What is the tangential velocity at the position between the stator and the rotor measured in a frame of reference fixed to the stator? (c)
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