Study on a Rapid Aerodynamic Optimization Method of Flying Wing Aircraft for Conceptual Design

Abstract

Searching for a design scheme satisfying the requirements in aircraft conceptual design can be a time-consuming work because of the multipeak and nonlinearity of the design space. This paper proposed a rapid aerodynamic optimization method for flying wing aircraft conceptual design. This method is aimed at reducing the induced drag at the design point by adjusting the camber and twist angle of spanwise airfoil. Firstly, the mean camber surface of the flying wing aircraft was parameterized. Secondly, the surrogate model was constructed based on the points selected by the optimization Latin square method. Thirdly, the surrogate model combined with a multi-island genetic algorithm was used for the preliminary solution of global optimum, and then, the Nonlinear Programming by Quadratic Lagrangian method combined with a vortex lattice method was used for searching the nearest exact best point from the initial best point. Finally, connecting with manual selection, the optimized flying wing layout scheme was obtained. The optimized results show that the induced drag coefficient is reduced by 10%, the pitching moment coefficient is reduced by an order of magnitude, and the lift drag ratio is increased from 26.3 to 27.3. The proposed optimization method decreases the time cost in aircraft conceptual design while achieving sufficient calculation accuracy. By using this method, the design space can be explored rapidly to search for the best design scheme satisfying the constraints.