1920 Phase-average Behavior of Backward Facing Step Flow in Low Reynolds Number by Synthetic Jets

The objective of this study is to control the reattachment process of the separating and reattaching flow over a backward facing step in a low Reynolds number range by the synthetic jet. The Reynolds number based on the step height ranges from 300 to 900. The synthetic jet has a frequency of 10, 36, 70, and 150Hz. In order to investigate the effect of the periodic disturbance on the reattachment process, Micro Flow Sensor was used for measurement of phase-averaged forward flow fraction. The results show effectiveness of the synthetic jet for flow control. The reattachment process strongly depends on Reynolds number and a vortex motion which is generated at the separating shear layer.