毫秒脉冲等离子体激励改善飞翼的气动性能实验

在来流速度为30m/s时，进行了毫秒脉冲介质阻挡放电等离子体激励改善飞翼气动性能的风洞实验.等离子体激励器布置在飞翼前缘，峰峰值电压为9.5kV时，放电的脉冲能量在0.1mJ/cm量级.通过六分量测力天平测力研究了脉冲激励频率和占空比对升/阻力系数、升阻比和俯仰力矩系数的作用效果.结果表明:等离子体激励可以有效改善飞翼大攻角气动特性；在最佳无量纲脉冲激励频率F+≈1时，临界失速迎角由14°提高到17°，最大升力系数提高10%；占空比对流动控制效果影响较大，减小占空比可以降低能耗，实验中最佳占空比为5%；俯仰力矩系数的变化表明施加等离子体激励改善了飞翼纵向静稳定性. 

Experiment for improving aerodynamic performances of a flying wing by millisecond pulsed plasma actuation

The experiment for improving aerodynamic performances of a flying wing by millisecond pulsed dielectric barrier discharge (DBD) plasma actuation was performed in a wind tunnel at incoming speed of 30m/s. Plasma actuator was planted along the leading edge of the flying wings; the discharge energy of each pulse was at the order of 0.1mJ/cm when the peak-to-peak voltage was 9.5kV. The effect of actuation frequency and duty cycle on the aerodynamic performances, such as lift/drag coefficient, lift/drag ratio and pitch moment coefficient, was investigated through force measurement by a six-component balance. The results show that the aerodynamic performances of the flying wing at high angles of attack can be improved with plasma actuation. When the optimum non-dimensional actuation frequency F+≈1, the stall angle of attack increases from 14° to 17° and the maximum lift coefficient increases by 10%. The duty cycle plays an important role in flow control efficiency. The best duty cycle is 5% in the current investigation, which can reduce the power consumption tremendously. Meanwhile, the changes of pitch moment coefficient indicate that longitudinal static stability of flying wing is improved by plasma actuation.