A mechanism study of active plasma actuations over a flow of an asymmetric vortex pair generated at the leeward of a 20°circular-cone-cylinder model at high angle of attack is presented. The tests are carried out at an angle of attack of 45°in a low-turbulence, low-speed wind tunnel of which the test section is 3.0 m × 1.6 m. The Reynolds number based on the cone base diameter is 50 000. A pair of Single-Dielectric-Barrier-Discharge ( SDBD) plasma actuators symmetrically located at starboard and port of the apex of the model respectively, alternately produce perturbations to the flow by duty-cycled control the frequency of which is 10 Hz. The experiment data demonstrate the separation vortex pair varies periodically and smoothly between two opposite states similar to the bi-stable patterns. The side force generated by the original asymmetric vortex pair is eliminated when the starboard and port actuators share the time equivalently in the duty-cycled period.%针对大迎角状态下,流动绕过顶角为20°的圆锥-圆柱组合体模型产生的一对不对称分离涡,通过等离子体激励器对其进行主动控制,并对控制过程机理进行了分析.实验在实验段为3.0 m×1.6 m的低湍流风洞中进行,实验攻角是45°.基于圆锥体底部直径的雷诺数为50 000.等离子激励器为一对,分别位于实验模型顶部左右两侧,通过频率为10 Hz的占空循环调节,交替对流动产生扰动.实验数据表明,当带有占空循环的激励作用时,分离涡的变化成周期性趋势,并在两个相似于双稳态分离涡型态之间过渡.实验结果表明,当左右激励器在一个占空循环周期中交替开启时间相等时,几乎消除了原有不对称分离涡产生的侧力,实现对不对称分离涡稳定性的控制.
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