合成射流对圆柱绕流流固耦合特性影响分析

利用合成射流对钝体绕流流动特性及流致振动进行了主动控制数值研究。结果表明:随着合成射流动量系数的增加,对圆柱涡激振动的抑制效果越好。随着射流位置从后驻点移向前驻点,圆柱尾流涡脱模态呈现出柱体背流面附着对称涡的定常状态-过渡状态-反对称2S涡脱落模式的演变过程。圆柱双自由度振动轨迹为“8”字形,完全受到抑制时轨迹为“一”字型,部分抑制时其轨迹为“月牙形”,合成射流的引入可有效降低圆柱所受升力,能有效的抑制圆柱横向和流向振动,当合成射流对位于圆柱背风侧的1/4弧边缘时,圆柱的流向振荡和横流振荡均可被抑制,其抑制效果最好。 

Analysis of effect of synthetic jet on fluid-solid coupling characteristics around cylinder

The active control of the characteristics of flow around a bluff body and flow-induced vibration was numerically investigated by using the synthetic jet. Results showed that the vortex-induced vibration of the cylinder was well suppressed with the increase of the momentum coefficient of synthetic jet. As the jet position moved from the rear stagnation point to the front stagnation point, the vortex shedding mode of the cylinder wake showed the evolution of the steady state-transition state-antisymmetric 2S vortex shedding mode attached to the backflow surface of the cylinder. The two-degree-of-freedom vibration trajectory of the cylinder was in the shape of “8”, “one” in the case of complete suppression, and “crescent” in the case of partial suppression. The introduction of synthetic jet can effectively reduce the lift force on the cylinder. When the synthetic jet was located at the edge of 1/4 arc on the leeward side of the cylinder, the in-flow oscillation and cross-flow oscillation of the cylinder can be suppressed with the best suppression effect.