Stability Analysis of Supersonic Cascade Flow by Actuator Disk Methods

抄録

This paper presents the results of a two-dimensional stability analysis on supersonic flow relative to a cascade, using actuator disk methods. The results show the possibility of existence of two types of destabilizing mode in the supersonic cascade flow. One mode corresponds to conventional rotating stall in subsonic cascade flows. This mode can be unstable both in subsonic and supersonic regions, and its propagation velocity ratio(absolute propagation velocity / rotor speed)is smaller than unity. The other mode is a newly found mode unique to supersonic cascade flows. This mode can become unstable only in the supersonic region, and its propagation velocity ratio is for the most cases larger than unity. Both modes become unstable due to the positive slope of the characteristic curves caused by flow compressibility as in the case of, for example, a shock wave.