Multistage axial flow compressor stability improvement structure based on sawtooth tailing edge blade

Abstract

The invention discloses a multistage axial flow compressor stability improvement structure based on a sawtooth tailing edge blade. The sawtooth tailing edge is arranged on a blade of a multistage axial flow compressor to form a sawtooth tailing edge blade, and the sawtooth tailing edge blades are arranged on one or more blade rows of the multistage axial flow compressor; the tooth height H of onesawtooth tailing edge blade is 8%-16% of the blade chord length, the tooth apex angle theta is 20 degrees-60 degrees, and the tooth number is 1-20; the sawtooth trailing edge blades are provided withsawtooth structures near the blade tips or the blade roots; and the sawtooth tailing edge blades are arranged symmetrically in the circumferential direction of the blade row, or the whole blade row isprovided with the sawtooth tailing edge blades. According to the structure, the sawtooth configuration and the pressure difference on the two sides of the blades are utilized to generate the streamwise vortex, the streamwise vortex sucks the main flow into the vortex and interacts with a tailing trace shearing layer, a large-scale vortex structure in the tailing trace is broken away, the shape ofthe blade tailing trace and the characteristic of the flow field concerned with the downstream blades are improved, the stall of the compressor is delayed, and the stability margin of the compressoris widened. The sawtooth tailing edge blade structure has the advantages of no other equipment, light structure weight and the like.

Description

technical field [0001] The invention belongs to the technical field of aerodynamics, and in particular relates to a multi-stage axial flow compressor stability expansion structure based on sawtooth trailing edge blades, and is a new type of aviation axial flow compressor expansion stability measure. Background technique [0002] Future high thrust-to-weight ratio engines require the fan / compressor to have a higher stage pressure ratio, and the higher the stage load of the fan / compressor, the more stringent the stability requirements. Stability is a measure of the anti-interference and anti-distortion capabilities of the fan / compressor, and is related to the response of the fan / compressor working at a stable operating point to external disturbances. High stability indicates that the fan / compressor can overcome disturbance factors and maintain stable and normal operation . As the fans / compressors have much more available stability margin, their stability is of course higher. ...

AI Technical Summary

Problems solved by technology

[0005] According to the assumption of the critical angle of attack for compressor instability, when the incoming flow angle of attack of some blades in the blade row exceeds its critical angle of attack, a large separation flow will occur, which will cause the compressor to rotate stall or surge.

When the upstream wake sweeps, the transient angle of attack felt by the blades may exceed the critical angle of attack and induce compressor stall

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