Airfoil Optimization Design, The Genetic Algorithm And Cfd Technology

Airfoil performance has a decisive impact on the aerodynamic characteristic of an aircraft. High-performance aircraft is a basic research in modern aircraft development. High-lift, lower-draft airfoil is the goal pursued in procedure of airfoil design. The mathematical model of the optimum design is given. Firstly airfoil pressure surface and the suction surface are built by B-Spine curves method. The optimization model is established by modifing the weight coefficient of control point. The lift coefficient, the draft coefficient and other aerodynamic parameters are obtained by means of the numerical simulation of Navier-Stokes equations. Objective function is defined as the lift-to-drag ratio. Optimizing design starts from a basic airfoil and finally builds a new airfoil shape through modifying the airfoil design parameters. A good aerodynamic performances airfoil is built under genetic algorithm.The finite volume method of two-dimensional steady Navier-Stokes equations is studied by O grid generated by means of TTM. In calculation , explicit five-step Runge-Kutta is applied to time stepping scheme; Ooscillating near the shock wave is eliminated by introducing artificial dissipation; Iterative calculation is accelerated by local time step and anisotropic implicit residual smoothing etc; The Baldwin - Lomax algebraic model is used for turbulence simulation.The genetic algorithm is studied and improved on the coding method and genetic operator etc. Genetic algorithm and CFD is combined together to optimize airfoil. The efficiencies of optimum design are greatly improved by employed response surface methods. Some valuable conclusions are obtained, by which the feasibility and efficiency of the model is proved good.In addition, flight simulation is studied in this paper. Aerodynamic characteristic curves are fitted by the least-squares fitting method. Flight equations are solved by Runge-Kutta method, and the visualized program is designed. An effective method for the design of flight simulator is provided.