连续吹喷-抽吸控制方法对圆柱尾流的影响

The flow separation behind a bluff body causes adverse effects such as increased resistance and fluctuation of lift force. Therefore, it is of great importance to control the flow separation on the bluff bodies so as to improve their mechanical properties. An active control method, which combines continuous blow and suction, is employed to circular cylinders, and the wake characteristics of cylinders are researched systematically using an IFA300 constant-temperature anemometer in a small low speed wind tunnel. Test results show that the combination of front suction and rear blow can significantly weaken the flow separation of cylinders, reduce the range of wake region, and greatly suppress the turbulence of this region.The increase in blow-suction velocity and angle can both promote the effectiveness of flow control in the test range, especially for cases with angle of 50° or 70° and a velocity which is three times the inflow velocity. In this instance, the low velocity zone behind the cylinder is almost disappeared, and the turbulence decreases greatly, which is even less than 5% of turbulence when the cylinder is not controlled.By comparing the control effects of a circular cylinder with single front continuous suction or single rear continuous blow, it is found that the contribution of rear blow is much greater than that of the front suction in the continuous blow-suction control method, which indicates that the former plays a key role to efficiently control the cylinder wake flow.