Flow Near a Rotating Disc with Stagnation Flow

Abstract

An experimental investigation of flow near a rotating disc with stagnation flow has been carried out. Flow visualization indicates that a circulating flow appears on the disc and fluctuates with a frequency of half to one sixth of that of the rotating disc. Measurements of circumferential velocity have been made by a laser Doppler velocimeter. The result shows that the transition to turbulent flow occurs at a local rotational Reynolds number of 1.5 × 10⁵, and the velocity fluctuates with a frequency 28-times as large as that of the rotating disc in the transitional region. The time smoothed circumferential velocity in the laminar region is in good agreement with the theoretical value of the free disc, irrespective of the Reynolds number of the approaching flow.