纳秒脉冲表面介质阻挡放电激励改善飞翼力矩特性的实验研究

Experimental Study on Improving Flying Wing Torque Characteristics by NS-DBD Actuation

关键词:  飞翼  等离子体  流动控制  升阻特性  力矩特性

Key words:  Flying wing  Plasma  Flow control  Lift resistance characteristic  Torque characteristic

摘要:

针对飞翼布局力矩控制问题，采用纳秒脉冲表面介质阻挡放电（NS-DBD）激励，在来流风速30 m/s时，开展飞翼等离子体流动控制风洞试验，研究了不同激励参数和位置对飞翼升阻特性和力矩特性的影响。结果表明，NS-DBD激励能够有效改善飞翼大迎角气动特性。激励频率对飞翼升阻特性影响较大，激励频率为0.2 kHz时，增升效果最好，最大升力系数提高14.5%，失速迎角推迟5°。随着激励频率的增加，增升效果逐渐变差，减阻效果变好。单侧施加激励时，能够实现大迎角下飞翼模型的力矩控制，随着激励频率的增加，滚转力矩的控制效果减小，偏航力矩的控制效果增大，俯仰力矩的控制效果减小。根据PIV流场测量结果可知，在单侧施加等离子体激励，可以抑制机翼表面流动分离，使其升力增大，阻力减小，从而诱导产生滚转力矩和偏航力矩。在中翼段和内翼段施加激励，破坏了飞翼的俯仰力矩特性，在外翼段和机翼右侧施加激励，能够显著改善飞翼的俯仰力矩特性。根据PIV流场测量结果可知，在单侧施加等离子体激励后，会减弱外翼的横向流动，并且增加机翼前缘的速度，同时抑制流动分离，从而减小飞翼的抬头力矩。NS-DBD激励为改善飞翼布局稳定性和操纵性提供一种潜在的技术手段。

Abstract:

Aiming at the problem of moment control of flying wing layout， a wind tunnel test of plasma flow control of flying wing with nanosecond pulse dielectric barrier discharge （NS-DBD） was carried out when the wind speed was 30 m/s. The effects of different actuation parameters and positions on the lift resistance and torque characteristics of flying wing were studied. The results show that NS-DBD actuation can effectively improve the aerodynamic characteristics of flying wing at high angle of attack. The actuation frequency has a great influence on the lift-drag characteristics of flying wing. When the actuation frequency is 0.2kHz， the effect of lift-up is the best， the maximum lift coefficient increases by 14.5%， and the stall angle of attack is delayed by 5°. With the increase of actuation frequency， the effect of lifting becomes worse and the effect of drag reduction becomes better. When unilateral actuation is applied， the torque control of the flying wing model at a high angle of attack can be realized. With the increase of actuation frequency， the control effect of rolling moment decreases， the control effect of yaw moment increases， and the control effect of pitching moment decreases. According to the measurement results of the PIV flow field， applying plasma excitation on one side can suppress the flow separation on the wing surface， increase its lift， and reduce the drag， thereby inducing the roll and yaw moments. The pitching moment characteristics of the flying wing were destroyed by actuation in the middle wing and the inner wing， while the pitching moment characteristics of flying wing could be significantly improved by actuation in the outer wing and the right wing. According to the PIV flow field measurement results， after applying plasma excitation on one side， the lateral flow of the outer wing will be weakened， and the speed of the leading edge of the wing will increase. At the same time， the flow separation will be suppressed， thereby reducing the head-up moment of the flying wing. NS-DBD actuation provides a potential technical means to improve the layout stability and maneuverability of flying wings.