多级双极性等离子体激励器加速气流的实验研究

等离子体激励器是一种新型的流动控制手段，通过其产生的等离子体加速气流，从而实现对流动的控制．然而，单一等离子体激励器因其加速气流的效果受到自身流向长度的限制，其应用范围通常被局限在小尺度的物体上．目前采用的解决方法是将多个传统等离子体激励器并联成一组，形成多级激励器，然而前后电极的相互干扰大大降低了这种多级激励器的工作效率．本文提出了一种新型等离子体激励器的串联方案，也就是将多级激励器中前一级的下电极都与后一级的上电极相连，形成一种新型多级双极性等离子体激励器．粒子示踪测速系统（PIV）对该激励器加速气流的实验结果表明，这种新型多级激励器能够消除前后电极之间的相互干扰，大大提高多级等离子体激励器加速气流的效率．

Experimental study of flow acceleration using plasma actuator of multi-bipolar electrodes

Dielectric barrier discharge （DBD） plasma actuators can be used in flow control applications due to the momentum transfer from plasma to fluid. Due to geometry limitation, however, only small trust can be obtained by DBD plasma actuators, which limits its application in large-scale flow problems. Usually, several surface DBDs are combined in series to obtain a single multistage actuation surface. However, the mutual interaction between successive discharges limits the effectiveness of such multi-DBD actuators. In this paper, a new multi-bipolar DBD plasma actuator is proposed for large-scale flow control applications. An innovative method for constructing multiple plasma actuators of bipolar electrodes is introduced to enhance the thrust. Multi-bipolar electrodes are adopted with the electrode of former covered electrode and later exposed electrode connected together. To validate the proposed method, particle image velocimetry （PIV） experiments are performed. The results show that cross-talk phenomenon can be reduced greatly and thus a constantly accelerating electric wind velocity can be obtained above the multi-bipolar actuator. It is concluded that compare to traditional actuators the new configuration can increase the thrust significantly.