The Aerodynamic Optimization Method Based On Configuration Dynamic Evolution Control For N-S Equations

In this dissertation, the aerodynamic optimization method based upon configuration dynamic evolution control, developed by academician ZHANG Hanxin, is applied to optimise the two-dimensional airfoil shape and configuration of three-dimensional lifting body.Via the brief review to the development of computational fluid dynamics (CFD), the feasibility and importance of the aerodynamic configuration design based on CFD are explained. The status of some popular aerodynamic optimization designs is discussed.Four aspects in the process of aerodynamic optimization are introduced, as CFD analysis, configuration parameterization, gravity computation and optimization algorithm. In CFD analysis, the efficiency and robustness are concerned; inheriting the existing non-structural grids and limited volume algorithm, it is taken full advantage of non-structural grids' self-adaptability of generating the new grids when the tiny changes occur, instead of generating new grids again in the whole field, saving the time for grids generation. In configuration parameterization, different methods are applied according to specific configuration and design goal. For two-dimensional airfoil shape, parameterization is coupled with B spline method, while character measurement parameterization is applied to configuration of 3-dimension lifting body. In gravity computation and optimization, the method developed by ZHANG Hanxin is used. By solving non-stationary N-S equations (not by solving convergence solution of stationary N-S function ), the values of flow field object function which vary according to the configuration are obtained, and the object function's gravities to control variable are gained, then the appropriate directions are selected for configuration change according to the gravities, till meeting the requirements. Finally, the optimization examples for two-dimensional and three-dimensional problems are presented to demonstrate the success of the aforementioned methods.The dissertation is divided into five chapters. Chapter 1 is the introduction, discussing CFD, non-structural grid method and development of aerodynamic configuration optimization. Non-structural grids technology, dynamic grid technology and limited volume method is given in chapter 2. In Chapter 3, the parameterization method and aerodynamic optimization method based on configuration dynamic evolution control for two-dimensional airfoil shape and three-dimensional lifting body are introduced. Chapter 4 and Chapter 5 present optimization examples for two-dimension airfoil shape and there-dimension lifting body respectively. Chapter 6 draws a conclusion, pointing the lacks and future potential work.