平角旋转机构约束的管射无人机二次折叠翼气动优化设计

The twice folding wing can effectively increase the aspect ratio of the wing of tube-launched UAV and improve the cruising efficiency of the UAV. However, the flat-angle rotation deployment mechanism increases the thickness of the profile between the inner and outer wings, reducing the aerodynamic performance and worsening the cruise performance of the twice folding wing. Therefore, it is of great significance to establish the aerodynamic design method for the twice folding wing. In this paper, an aerodynamic optimization design for the twice folding wing is developed considering the geometric constraints of the second deployment mechanism. Firstly, the Free Form Deformation (FFD) technique is used to parameterize the twice folding wing. Then, combined with CFD solver and Genetic Algorithm, an aerodynamic optimization design system is developed. Finally, the absolute thickness constraint is transformed into the constraint of the variation range of the design variables for the FFD control points by solving the influence coefficient. The optimization design system is used to the design optimization of the twice folding wing under design conditions lift coeffiaient 0.68 considering constraints of mechanism. The result shows that the aerodynamic drag coefficient of the twice folding wing decreases by 9.3%, satisfying the constraint of the deployment mechanism. The developed optimization design system can effectively improve the aerodynamic characteristics of the twice folding wing.