基于等离子体激励的湍流边界层减阻控制

Drag reduction control of turbulent boundary layer based on plasma actuation

为了探究介质阻挡放电(dielectric barrier discharge, DBD)等离子体气动激励对平板湍流边界层的减阻情况,在控制来流速度为10.7 m/s的低速风洞中进行等离子体平板湍流边界层减阻控制实验。本实验重点研究了不同激励频率对湍流边界层的减阻控制效果,使用热线风速仪系统采集流向速度信号,获得边界层平均速度分布和脉动速度分布。对实验结果进行对比分析发现,在施加不同频率的等离子体激励之后,边界层内对数区速度明显减小;随着激励频率的增加,局部减阻率呈现出先增大后减小的趋势,在激励频率为200 Hz时,减阻率达到最大为7.4%。

In order to further explore the drag reduction effect of the turbulent boundary layer by the dielectric barrier discharge(DBD)plasma actuation,an experimental study was performed to reduce the flat plate turbulent boundary layer drag in a low-speed wind tunnel with a freestream velocity of 10.7 m/s.This experiment focused on the drag reduction of different pulsing frequencies on the flat plate turbulent boundary layer.The hot wire anemometer system was used to collect the streamwise velocity signal,and acquire the mean velocity distribution and fluctuation velocity distribution within the turbulent boundary layer.A comparative analysis of the experimental results showed that the plasma significantly reduced the mean velocity in the logarithmic region of the boundary layer,and as the pulsing frequency increased,the local drag reduction showed a trend of first increased and then decreased.When the pulsing frequency of 200 Hz,the maximum local drag reduction rate was 7.4%.