Performance optimization of SG6043 airfoil using the combination of Gurney flap and boundary layer trip in low Reynolds number flow
摘要
High-Altitude Long-Endurance Unmanned Aerial Vehicles (HALE UAV) operate in low Reynolds number flow because of the low density in the high altitude environment. It is needed to improve the aerodynamic performance of the airfoil in low Reynolds number flow for high loads capacity and long endurance. Passive flow controls are simple and efficient method to improve the performance of airfoil and is of interest to researchers. Therefore, the objective of this paper is to increase the lift coefficient and endurance ratio of SG6043 airfoil using the combination of passive flow controls-Gurney flap and boundary layer trip. First, computational fluid dynamics (CFD) simulations were used to investigate the effect of Gurney flap and trip on the performance of the airfoil. Second, an iterative algorithm was constructed to optimize the performance of the SG6043 airfoil by the height of Gurney flap, the location and height of the trip. The optimal space-filling method (OSF) was used to generate an initial database for the response surface configuration. During each iteration, the optimum point is searched on Kriging response surface using genetic algorithm (GA) to maximize the endurance ratio of the airfoil. CFD validation is carried out on the obtained optimum point and the response surface was reconstructed by adding new CFD results to the database. The optimization results showed that the proper combination of Gurney flap and trip can increase endurance ratio and lift coefficient of SG6043 airfoil simultaneously without drag penalty. Compared with the original airfoil, this combination increased the endurance ratio and lift coefficient of airfoil by 12.9% and 8.5% respectively at an angle of attack of