Author(s): Shao Xuejun; Chen Zhicong; Hu Huiwu; Ma Yongjun
Linked Author(s):
Keywords: Boundary layer control; Circulation; Suction and blowing
Abstract: This paper presents an experimental investigation into the use of boundary layer control method to reduce the size of a horizontal circulation behind a boundary protrusion, simulated by a spike dam. Experimental results show a more than 90% reduction of the circulation length when the “suction” and “blowing” method is used in flow about the spike dam. The circulation size is quite sensitive even for small increases in Q_S, when Q_S <0.01~0.02Q_F. After suction discharge Q_S exceeds a certain level, e.g., Q-S =0.02 Q_F, circulation size remains stable and does not show sensitivity to further increases in Q_S. Large Q_S can then produce a new circulation at the boundary opposite to the spike dam. From experimental results it can be seen that an optimal suction discharge exists which is large enough to reduce the circulation length to the required range (25~50cm in this study), and small enough compared with the flume discharge. For each of the four runs an optimal discharge is found out. Based on theoretical results and dimensional analysis, the following non-dimensional parameter, Λ, is found to adequately represent the related hydraulic factors
Year: 2001