斜出口合成射流激励器横流输运特性与边界层控制

研制了一种斜出口合成射流(BSJ)激励器,应用粒子图像测速(PIV)技术获得了合成射流的瞬态和时均流动结构,分析比较了斜出口和常规平直出口激励器流场的异同。该斜出口激励器能将周围气体进行有方向的能量和质量输送控制,时均流场呈现沿壁面的横向流动输运特性。解释了横向流动输运的形成机理,并应用该激励器进行了边界层控制实验。研究结果表明:通过改变激励器的工作电压和频率,可方便有效地实现对平板边界层速度型的调控,使受控边界层速度型更"饱满",这对控制推迟边界层分离非常有利。

Cross Flow Transfer Characteristics of a New Beveled Synthetic Jet Actuator and Its Applications to Boundary Layer Control

This article describes a new beveled synthetic jet (BSJ) actuator whose unsteady flow fields are measured by means of the particle image velocimetry(PIV).The instantaneous flow maps and ensemble-averaging flow fields are given.The flow structure of the BSJ is compared with that of a conventional synthetic jet.The results show that the energy and mass fluxes of fluid near the BSJ actuator are transferred horizontally along the wall.Furthermore,the physical mechanism of the formation of the BSJ and mass flux transfer are explained.Experiments of BSJ boundary layer flow control are conducted.It is shown that by changing the forcing frequency and amplitude of the BSJ actuator,the mean velocity profile of a flat plate boundary layer can be easily changed and makes it more"fuller"than if the jet is off.The characteristics of the BSJ actuator eahibit a potential to be applied tO boundary layer separation delay control.