Experimental analysis about the magnitude of the shaft frequency growth near stall in the axial compressor

Abstract

The experimental study investigates the cause of prestall, which the magnitude increases of the shaft frequency near stall. This prestall phenomenon is related to the geometric non-uniformity of the axial compressor, which can be classified into blade non-uniformity and casing non-uniformity. The instant static pressure was decomposed into several signal components to investigate this phenomenon. To verify the blade non-uniformity, the dimensionless revolution aperiodic component (Ψ) distribution, which was measured at one arbitrary circumferential location, was analyzed, and to verify the casing non-uniformity, the amplitude of Ψ was analyzed at 8 equally spaced circumferential locations of the first stage. The measurements showed that the blade non-uniformity directly caused the increase of the magnitude of the shaft frequency near stall but that the casing non-uniformity induced the increase of the magnitude of the shaft frequency in the Seoul National University compressor.

Experimental Research on Aerodynamic Instabilities in a Multi Stage Transonic Axial Compressor

“…∼ (6) 국내에서도 원심형 압축기의 스톨/서지관련 시험은 체계적으로 수행되어 왔으며 논문으로도 다수 보고되어있다. (7) * 한국항공우주연구원 항공추진기관팀 ** 서울대학교 기계항공공학부 대학원 † 교신저자, E-mail : electra@kari.re.kr 하지만 국내의 축류형 압축기 스톨시험은 서울대학교에서 보유하고 있는 저속 스톨시험이 유일했으며 (8), (9) , 최근에는 스톨 억제 및 제어 연구결과가 보고되고 있다. (10)…”