关键词: 机翼, 跨声速, 优化设计, 工程使用要求, 计算流体力学

Abstract: In order to get tradeoff between aerodynamic characteristic and aircraft design requirements for the transonic wing, the paper puts forward a two step design strategy which combines the wing planform and wing section optimization based on constraints of wing structure weight and volume, using neural network and genetic algorithm, we set up the corresponding design method. For the transonic wing multi- point optimization problem using the two step design strategy, in the first design step, improvement of wing’s aerodynamic characteristic is mainly depended on the increase of wing aspect ratio which reduces induced drag during the wing planform optimization, however, this improvement is very limited because wing structure weight constraint leads to a little change of wing geometry. In the second design step, improvement of wing’s aerodynamic characteristic is mainly depended on the weakening of shock which reduces wave drag during the wing section optimization. Two points design are studied, the results show that the lift to drag ratio increment can reach to 3.02% for the first design point and 9.96% for the second design point, and drag divergence Mach number can be postponed from 0.854 to 0.8653. The pure aerodynamic optimization, including planform and wing section optimization design, is applied for transonic wing design without structure weight and volume constraints, the results show that the improvement of aerodynamic characteristic is significant but unsatisfying with constrains of structure weight and volume.

Key words: Wings, Transonic speed, Optimization, Engineering application, CFD