Multi-objective Aerodynamic Optimization for Telescopic Wings Considering Space Constraints

Deformable wing technology enhances aircraft aerodynamic, with telescoping wings being highly effective. This paper proposes a pneumatic optimization technique for small telescopic wing UAVs. First, a genetic algorithm was used to build the optimization framework based on the two working conditions (the inlet air velocity is 15 m/s and 30 m/s, respectively) for telescoping wing aircraft. By using the CST (Class Shape Transformation) method, the airfoil is represented in parameterized form, with several variables controlling its shape. The objective of optimization is to minimize the weighted drag coefficient under the two working conditions. Then, the optimized airfoil is extended to three dimensions. The space constraint model of the inner wing is established to give the range of parameterized variables. The FFD (Free form deformation) method is used for parametric modeling of the outer wing. The genetic algorithm is used to adjust the outer wing design variable to minimize the drag coefficient when the outer wing of the telescopic wing is fully deployed. The optimization results show that the drag coefficient of the optimized airfoil decreases by 6.60% from 0.01939 to 0.01811 when the velocity is 15 m/s (the wing is fully deployed), while it decreases by 5.94% from 0.017 to 0.01599 when the velocity is 30 m/s (the wing is fully contracted). And the drag coefficient of the wing is decreased by 1.69% from the initial 0.026743 to 0.026279. The results show that the proposed optimization strategy can effectively complete the aerodynamic optimization design of the telescopic wing.