Response of an axial flow compressor tolerant to steady circumferential pressure distortions with casing treatment of circumferential grooves

A model of distortion transfer matrix was presented for predicting the response of an axial flow compressor rotor ,stator and axial clearance to steady circumferential pressure distortion with two casing configurations; solid case and circumferential groove case, based on blade row experimental characteristics . With inlet total pressure distortions ,it is found that the casing treatment of circumferential grooves that improves the stall margin of axial flow compressors under uniform inlet conditions is still superior to the solid case . By using this kind of casing treatment, great attenuation of total pressure distortion, weak incidence angle changes and low total temperature distortion production through the rotor was obtained. It is apparent that the effective improvement in stall margin can be achieved with this casing treatment under conditions of inlet circumferential pressure distortions. Some suggestions were made to design axial compressors high tolerant to inlet steady distortions.