基于合成射流的二维后台阶分离流主动控制

发布时间：2018-08-28 09:45

【摘要】：作为一种新的流动控制激励器,合成射流技术在流动分离控制、降低压力脉动和抑制噪声等方面具有广阔的应用前景。实验利用合成射流主动控制技术对二维后台阶湍流分离再附流动控制进行了研究,应用表面测压、粒子图像测速(PIV)和热线等多种实验测试技术对后台阶表面压力分布、流场结构以及剪切层特性进行了测试。结果表明,在台阶前缘施加合成射流可有效减小回流区范围和降低再附长度,当合成射流的动量系数为0.301×10-3时,可使再附点长度减小25%。合成射流控制使得沿台阶下游的湍动能和雷诺应力增强,提高了台阶下游流场的混合效率。热线动态结果表明频率是后台阶分离流动控制的关键参数,当频率为260Hz、激励频率与剪切层涡脱落频率之比为1.32、激励频率等同于旋涡脱落频率时,合成射流控制效果最好,仅需消耗较小的能量即可实现流动控制的目的。
[Abstract]:As a new flow control exciter, synthetic jet technology has broad application prospects in flow separation control, pressure fluctuation reduction and noise suppression. In this paper, the control of two-dimensional turbulent separation and reattachment flow is studied by using synthetic jet active control technique. Surface pressure measurement, particle image velocimetry (PIV) and hot wire are used to measure the pressure distribution on the back step surface. The flow field structure and shear layer characteristics were tested. The results show that the application of synthetic jet at the front edge of the step can effectively reduce the circumfluence zone and the reattachment length. When the momentum coefficient of the synthetic jet is 0.301 脳 10 ~ (-3), the length of the reattachment point can be reduced by 25%. The turbulent kinetic energy and Reynolds stress along the lower step are enhanced by the control of the synthetic jet, and the mixing efficiency of the downstream flow field is improved. The hot wire dynamic results show that the frequency is the key parameter in the control of backward step separation flow. When the frequency is 260 Hz, the ratio of excitation frequency to shear layer vortex shedding frequency is 1.32, and the excitation frequency is equal to the vortex shedding frequency, the synthetic jet control effect is the best. The purpose of flow control can be achieved with less energy consumption.
【作者单位】：西南科技大学土木工程与建筑学院;南京航空航天大学航空宇航学院;
【基金】：空气动力学国家重点实验室基金(JBKY14010201)~~
【分类号】：O358

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