The NASA two-stage fan was tested with a low-aspect-ratio first-stage rotor having no misspend dampers. At design speed the fan achieved an adiabatic design efficiency of 0. 846, and peak efficiencies for the first stage and rotor of 0. 870 and 0.906, respectively. Peak efficiency occurred very close to the stall line. In an attempt to improve stall margin, the fan was retested with circumferentially grooved casing treatment and with a series of stator-blade resets. Results showed no improvement in stall margin with casing treatment but increased to 8 percent with stator-blade reset.
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