A Study of Instability Phenomenon in a Supercritical Diffuser Flow

点击翻译按钮获取中文摘要

1. The behavior of a shock wave in a supercritical diffuser under a constant overall pressure ratio is classified into a stable oscillation about its mean shock position and an unstable one where a shock wave is generated downstream of its throat and moves upstream and the cycle is repeated.2. An analysis of the stability criterion of a shock wave which interacts with periodic, lowfrequency downstream pressure disturbances has been performed taking the diffuser efficiency of the subsonic flow downstream of a shock wave into consideration.3. The behavior of stable and unstable shock waves in a two-dimensional circular diffuser has been experimentally clarified by a schlieren optical method and by pressure measurements.4. The response and subsequent motion of shock waves by the interaction of small-amplitude pressure disturbances are presended as a function of the Mach number where the shock is initially located and the diffuser efficiency of the subsonic region downstream of the shock.5. The curve of neutral stability which relates the diffuser efficiency to the Mach number of a shock wave is obtained and it is shown that the criterion agrees well with the present experimental results as well as with the previous experimental ones.