*Article* **Experimental Study on Plasma Flow Control of Symmetric Flying Wing Based on Two Kinds ofScaling Models**

**Like Xie 1, Hua Liang 1,\*, Menghu Han 2, Zhongguo Niu 3, Biao Wei 1, Zhi Su 1 and Bingliang Tang 1**


Received: 8 September 2019; Accepted: 6 October 2019; Published: 9 October 2019

**Abstract:** The symmetric flying wing has a simple structure and a high lift-to-drag ratio. Due to its complicated surface design, the flow field flowing through its surface is also complex and variable, and the three-dimensional effect is obvious. In order to verify the effect of microsecond pulse plasma flow control on the symmetric flying wing, two different sizes of scaling models were selected. The discharge energy was analyzed, and the force and moment characteristics of the two flying wings and the particle image velocimetry (PIV) results on their surface flow field were compared to obtain the following conclusions. The microsecond pulse surface dielectric barrier discharge energy density is independent of the actuator length but increases with the actuation voltage. After actuation, the stall angle of attack of the small flying wing is delayed by 4◦, the maximum lift coefficient is increased by 30.9%, and the drag coefficient can be reduced by 17.3%. After the large flying wing is actuated, the stall angle of attack is delayed by 4◦, the maximum lift coefficient is increased by 15.1%, but the drag coefficient is increased. The test results of PIV in the flow field of different sections indicate that the stall separation on the surface of the symmetric flying wing starts first from the outer side, and then the separation area begins to appear on the inner side as the angle of attack increases.

**Keywords:** symmetric flying wing; plasma flow control; energy; stall; dimensionless frequency; particle image velocimetry
