Modification of Axial-Flow Compressor Stall Margin by Variation of Stationary Blade Setting Angles.

摘要

The useful operating range of the multistage, axial-flow compressor component of a gas turbine engine limits the extent of operation of that engine. Generally, the compressor stalls or surges at a low flow rate and chokes a a high flow rate. Thus, any improvement in the range between these compressor aerodynamic limits is normally of benefit to the engine also. An idea for delaying the onset of rotating stall in a multistage, axial-flow compressor which involved circumferentially varying the blade setting angles of stationary blades upstream of the compressor rotors was investigated. Tests involving two low-speed, multistage, axial-flow compressors and an intermediate-speed, three-stage, axial-flow compressor were completed. Comparisons between baseline compressor (circumferentially uniform setting angles) and modified compressor (circumferentially varying setting angles) performance data were made. A variety of blade setting angle circumferential variation patterns were tested.