난류박리기포에 대한 비정상 후류의 영향

Abstract

An experimental study was made of turbulent separated and reattaching flow over a blunt body, where unsteady wake was generated by a spoke wheel-type wake generator with cylindrical rods. The influence of unsteady wake was scrutinized by altering the rotating direction (CW and CCW) and the normalized passing frequency (0 StH/ 0.20). The Reynolds number based on the cylindrical rod was Red/=375. A phase-averaging technique was employed to characterize the unsteady wake. The effect of different rotating directions was examined in detail, which gave a significant reduction of xR/. The wall pressure fluctuations on the blunt body were analysed in terms of the spectrum and the coherence.