*Article* **A New Flow Control Method of Slat-Grid Channel-Coupled Configuration on High-Lift Device**

**Jingyi Yu and Baigang Mi \***

School of Aeronautics, Northwestern Polytechnical University, Xi'an 710072, China

**\*** Correspondence: mibaigang@163.com

**Abstract:** A slot formed between the slat and the main wing of the 2D high-lift device is used to accelerate the convergence of the flow to the upper surface of the main wing to improve the flow field quality. In order to further enhance flow characteristics, this paper proposes a design method for multi-channel leading-edge slats based on grid flow channels. On the one hand, a specific shape of a shrinking expansion tube is formed to improve the lift characteristics of the leading slat. On the other hand, the newly formed slot plays a similar role to that of the jet stream, delaying the separation on the upper surface of the main wing, making the separation point move back and helping to improve the lift characteristics of the main wing. The optimization of coupled slat-grid channel configuration is developed by using the DOE algorithm. The geometric parameters, such as coordinates and curve slope, are considered as design variables, and the maximum lift–drag ratio is taken as the optimization objective required to obtain the optimal configuration. The simulation and optimization results show that the lift coefficient increases by 3.3%, the drag coefficient decreases by 12.7%, and the lift–drag ratio increases by 18.4% of the optimal configuration compared with the original airfoil at an angle of attack of 16.3◦ .

**Keywords:** grid-fin; multi-element configuration; flow control; aerodynamic optimization; DOE optimization algorithm
