阵列式表面电弧等离子体气动激励控制三角翼流动分离的实验

Experiment on Flow Separation Control of Delta Wing by Array Surface Arc Plasma Pneumatic Actuation

关键词:  流动分离  阵列式  表面脉冲电弧  三角翼  等离子体气动激励

Key words:  Flow separation  Array  Surface pulse arc discharge  Delta wings  Plasma pneumatic actuation

摘要:

为探索多路阵列式微秒脉冲表面电弧放电（μs-SAD，Microsecond pulse surface arc discharge）对尖前缘小后掠三角翼流动分离的控制效果和作用机理，首先通过放电测试和纹影测试对多路阵列式μs-SAD的激励特性进行研究，揭示其对流场的作用原理，进一步将多路阵列式μs-SAD用于三角翼流动控制，开展了小后掠三角翼流动分离控制低速风洞实验，研究了来流速度、激励电压和激励频率等参数对控制效果的影响规律。结果表明：多路阵列式μs-SAD能够快速放热，单路瞬间放电能量可达68mJ，在流场局部可诱导产生冲击波；机翼前缘多路阵列式μs-SAD能有效改善三角翼大迎角气动特性，当来流速度为30m/s时，使最大升力系数提高27.2%，失速迎角推迟4°；来流速度增大到40m/s时，流动控制效果减弱，使最大升力系数提高15.5%；存在最佳激励频率使无量纲频率F⁺=1时，控制效果最好；激励电压存在阈值，其随来流速度的增加而增大，当激励电压超过阈值电压继续增大时，流动控制效果不再增强。

Abstract:

Aiming at exploring the control effect and action principle of multichannel array microsecond pulse surface arc discharge (μs-SAD) on the flow separation of the small swept-back delta wing with sharp leading edge, the discharge test and the schlieren experiment of multichannel array μs-SAD in still air were investigated firstly to study its actuation characteristics and reveal the principle of action to the flow field. Furthermore, multichannel array μs-SAD was used to the delta wing flow control, the low speed wind tunnel experiment on flow separation control of small swept-back delta wing were carried out and an analysis of the influence on it from parameters such as flow velocity, actuation voltage and actuation frequency was made. The results show that the multichannel array μs-SAD can produce rapid exothermic, single channel instantaneous discharge energy can reach 68mJ and the shock wave is induced locally in the flow field. The wing front multichannel array μs-SAD can effectively improve the aerodynamic characteristics of the delta wing. At a flow velocity of 30m/s, the maximum lift coefficient increased by 27.2%, the stall angle of attack delays 4°. With the increase of incoming flow velocity, the flow control effect decreases and the maximum lift coefficient increased by 15.5%. An optimum of the control effect shows that the best actuation frequency makes the dimensionless frequency F⁺=1. Moreover, the actuation voltage has a threshold value which increases with the increase of the incoming flow velocity, and when the actuation voltage exceeds the threshold voltage, the flow control effect does not improve with the increase of voltage.