论文部分内容阅读
为探索纳秒脉冲介质阻挡放电(NS DBD)对小后掠尖前缘三角翼的流动控制效果和作用机理,进行NS DBD用于改善其气动特性的测力试验和流动显示试验。当来流速度分别为30m/s和45m/s时,测力试验结果表明位于机翼前缘的NS DBD能很好地改善三角翼大迎角气动特性,其中来流速度为45m/s时最大升力系数提高了18.3%;研究了脉冲激励频率对流动控制效果的影响规律,最佳的无量纲激励频率F+≈1~2。在来流速度为20m/s时,采用粒子图像测速仪(PIV)研究了不同迎角下激励前后机翼背风面流场,表明NS DBD可改善上翼面旋涡结构,使分离涡附体并得到加强。基于试验结果,认为NS DBD进行三角翼前缘涡控制的机理是激励诱导分离剪切层周期性产生附体的分离涡,从而维持了上翼面大迎角时的涡升力。
In order to explore the flow control effect and mechanism of nanosecond pulse dielectric barrier discharge (NS DBD) on the small tip-leading delta wing, dynamometer test and flow test of NS DBD to improve its aerodynamic characteristics were carried out. When the flow velocities are 30m / s and 45m / s respectively, the results of the force test show that the NS DBD located at the leading edge of the wing can improve the aerodynamic characteristics of the delta wing at a high angle of attack. When the flow velocity is 45m / s The maximum lift coefficient is increased by 18.3%. The influence of pulse excitation frequency on the flow control effect is studied. The optimal dimensionless excitation frequency F + ≈1 ~ 2 is studied. At the flow rate of 20m / s, the particle image velocimeter (PIV) was used to study the leeward flow field before and after excitation at different angles of attack, indicating that the NS DBD can improve the vortex structure of the upper airfoil so that the separation vortex and Be strengthened. Based on the experimental results, it is considered that the mechanism of forward vortex control of the delta wing by NS DBD is to induce the separation vortex generated periodically by the separation shear layer, thus maintaining the vortex force at the high angle of attack of the upper wing.