IV. PERFORMANCE DATA FOR STATOR SETTING ANGLE OPTIMIZATION

摘要

Stator setting angle optimization tests were conducted on a two-stage fan to improve efficiency at overspend, stall margin at design speed, and both efficiency and stall margin at part speed. The fan has a design pressure ratio of 2.8, a flow rate of 184.2 lb/sec (83.55 kg/sec) and a lst-stage rotor tip speed of 1450 ft/sec (441.96 in/sec). Performance was obtained at 70, 100, and 105 percent of design speed with different combinations of lst-stage and 2nd-stage stator settings. One combination of settings, other than design, was common to all three speeds. At design speed, a 2.0 percentage point increase in stall margin was obtained at the expense of a 1.3 percentage point efficiency decrease. At 105 percent speed, efficiency was improved by 1.8 percentage points but stall margin decreased 4.7 percentage points. At 70 percent speed, no change in stall margin or operating line efficiency was obtained with stator resets although considerable speed-flow regulation occurred.