激励强度对等离子体合成射流的影响

The effect of actuation strength on the plasma synthetic jet

通过在Navier-Stokes方程组中添加体积力源项的方法,模拟了不同激励强度下等离子体合成射流,并研究了激励强度对流场特性的影响。计算结果表明,随着激励强度的增大,激励器附近壁面处的涡量增大,对应的涡对中心诱导的流向速度增大,从而导致涡核更加远离壁面,并被拉伸变长。对于等离子体合成射流的时均流场,其中轴线上的流向速度随着激励强度增大整体变大。在较小的激励强度下,射流半宽度随着激励强度的增大而增大;而激励强度很大时(>6 Dc0),激励强度对半宽度基本没有影响。沿流向的动量通量也随激励强度的增大单调增加。

The flow structures induced by plasma synthetic jet actuator were simulated based on a phenomenological model, which was realized by adding the body force source term to the tions. The simulation results indicate that, with the actuation strength increased, the v adjacent to the actuator becomes larger, which yields the streamwise velocity induced b come larger. At the same time, the vortex core goes further away from the wall, and Navier-Stokes equa orticity near the wall y the vortex pair bethe vortex would be more stretched. The actuation strength has a significant influence on the streamwise velocity in the time-av-eraged flow field, which can be indicated by the fact that the time averaged streamwise velocity on the center- line rises from 0.4m/s to 1.4m/s along with the actuation strength increase from Dco to 8Dco. When the actuation strength is relatively low, the half jet width increases with the actuation strength increase. However, at the situation of high actuation strength （〉6Dc0）, it remains nearly constant and has no apparentrelation with the actuation strength. The streamwise momentum flux also increases with actuation strength increase monotonically.