地面试验模拟高空等离子体流动控制效果

提出了一种利用地面试验研究不同海拔高度等离子体流动控制性能的方法,该方法基于等离子体诱导射流雷诺相似原则,首先通过测量不同气压下静止空气中等离子体诱导射流的雷诺数,确定地面模拟等离子体激励器的结构和激励参数,然后将该激励器用于风洞试验,最后根据风洞试验结果评估等离子体在不同海拔高度处的流动控制效果。利用该方法研究了等离子体控制临近空间S1223翼型,结果表明相同工作条件下等离子体诱导射流最大速度随着海拔高度增加而增大,但射流雷诺数逐渐降低;高海拔低气压下除了切向壁面射流,等离子体在激励器上方诱导出一个高速向下的法向射流;采用雷诺相似等离子体激励器控制雷诺数为7.1×104的S1223翼型表面流动,攻角为6°~20°时升力系数增大27%~43%,表明采用等离子体流动控制技术后临近空间飞行器的升力特性可得到显著提升。

High altitude plasma flow control simulation through ground experiment

The method which is used to study the plasma flow control performance at different altitudes by ground experiments is presented. The induced jet Reynolds number is measured in static air under different pressures at first, then the geometrical and electrical parameters of ground plasma model actuator will be obtained according to Reynolds similarity of the plasma induced jet. Secondly, the model actuator is applied to the wind tunnel experiments and the results can be used to estimate the plasma flow control performance at different altitudes. That plasma modifies the flowfield of S1223 airfoil is studied by this method. It is found that when the altitude increases, the maximal velocity of plasma induced jet increases but Reynolds number decreases under the same working conditions. The plasma can induce one high-speed normal jet towards wall above the actuator except the wall tangential jet under low pressure. The S1223 airfoil with Reynolds number 7.1×10⁴ controlled by the Reynolds similarity plasma model actuator is studied. It is found that when the angle of attack is 6°-20°, the lift coefficient increases about 27% to 43% which indicates that the lift performance of near space vehicle can be improved markedly by plasma.