DBD涡流发生器及其在角区流动控制中的数值研究

为明确介质阻挡放电(DBD)涡流发生器对马蹄涡的影响,在采用唯象模型的基础上,通过数值方法研究了DBD涡流发生器诱导产生流向涡的结构特性及其对马蹄涡的控制特性。研究结果表明,流动在激励器上游边缘处形成羊角涡,自由剪切层卷入流向涡的涡核并为其提供持续涡量;在柱体根部角区流动中,当对称面两侧激励器诱导流动指向对称面,诱导涡与马蹄涡环绕方向相反时,马蹄涡可以得到有效抑制,反之,则控制效果不佳。最后得出,诱导涡对下游马蹄涡的控制机制体现在其黏性扩散作用、掺混作用以及低压效应3个方面。

Numerical study of DBD vortex generator and application in junction flow control

In order to explore the effects of dielectric barrier discharges (DBD) vortex generator on the horseshoe vortex, the phenomenological model is applied in the paper to the numerical simulation. The characteristics of the streamwise vortex structure and its control on the horseshoe vortex are analyzed. The results indicate that the tornado-like vortex is formed at the edge of the upstream electrode, and streamwise vortex engulfs the free shear layer and gains continuous vortices. When the induced flows on the two sides of symmetry plane point to the symmetry and the direction of the induced vortex is opposite to the horseshoe vortex, the strength of horseshoe vortex can be suppressed effectively in junction flow at the root of the cylinder. Otherwise the control effect is poor. Three factors, the viscous diffusion of the induced vortex on horseshoe vortex, and the mixing and low pressure of the induced vortex, related to the control mechanism are pointed out.