微射流作动器出囗流场数值分析

Numerical Analysis of Micro Jet Actuator Flow Field

本文简要介绍了微射流作动器的工作原理及结构形状 ,应用涡量 流函数法对二维、粘性、非定常、不可压微射流流场进行了数值分析。针对微射流形成的特点 ,构造了一种微射流作动器出囗处周期性变化的吸 /排气速度边界条件。计算结果与已有的实验和理论分析结果进行了比较 ,证明了该方法的可行性。数值分析结果表明虽然微射流的净质量流率为零 ,但其动量流率却不为零 ;由于微射流作动器出口处速度的交替变化 。

This article introduced the operation principle and configuration of the micro jet actuator briefly, then the two dimensional, time dependent, incompressible as well as viscous ejection flow field was numerical analyzed applying the vorticity stream function method. In accordance with the peculiarily of the formation of the micro jet, one blow/suction boundary condition at the exit orifice of the micro jet actuator was formed. This method is feasible in handling the ejection flow field after the computational results are compared with the laboratory and theory results thus existed. It shows that although the net mass flux out of the actuator's cavity is zero, the momentum flux is nonzero, and due to the variations of the velocity at the actuator's exit orifice periodically, vortex pairs are formed and move away from the orifice.