Research On Key Technology Of Streamline Curve And Surface Construting

The idea of streamline design comes from the appreciation of the shape of fish and high-speed gliding birds and the research on natural life science. The technology is widely used in shape design of transportation vehicles, such as airplane and car. Also, as a visual style noun, "streamline" is extensively used in the industrial design. This paper carries on research on key technical problems of the methods for constructing streamline curve and surface. The methods include the integral ones based on subdivision and non-uniform subdivision and the ones of aerodynamic optimization design. Under the condition of modern scientific research, the study intends to further improve the technology and play potential roles of streamline curve and surface. The main research contents and creative achievements are as follows:Streamline curve can be expressed as the integral curve of unit quaternion curve. Through analyzing the integral expression, the formula of streamline curve with an arc-length parameter is deduced. Thus, the paper proposes the subdivision algorithm of endpoint interpolation B-spline unit quaternion curve on the Gaussian sphere and the one of integral interval based on non-uniform subdivision. And the construction method of streamline curve and surface in integral form is designed. Also the effect on the shape of surface is discussed by changing arc-length parameters and integral interval. Further, the technique is applied to constructing the streamline rotation surface, and the shape of the surface is appropriately adjusted by altering parameters.According to the knowledge of geodesics, linear interpolation on Gaussian sphere is devised. And the paper presents the subdivision algorithm of endpoint interpolation non-uniform B-spline unit quaternion curve on the Gaussian sphere. In view of the above subdivision method of integral interval, so the constructing technology of streamline curve and surface is contrived on the basis of non-uniform subdivision. Then, the smooth blending of the streamline surface is studied with non-uniform bicubic B-spline surface and with Catmull-Clark subdivision surface. And the sufficient condition of the two G1 blending is induced. Moreover, the blending method of two bicubic B-spline surface is designed. Meanwhile, the shape of the streamline surface is properly adjusted by altering parameters.With airfoil inverse design as representation, the paper researches the construction method of streamline curve on basis of aerodynamic characteristic. In the approach, Laplace equation is used for flow equation, and the data are achieved quickly with flow problem solved by panel method. Then the airfoil curve can be expressed as quintic non-uniform B-spline curve. And also a hybrid genetic algorithm is contrived for the optimal problem. Furthermore, the special operators, which include crossover, mutation and local searching, are designed to improve the searching capability of the optimization algorithm.On the basis of airfoil inverse design, The method of construction surface is contrived according to aerodynamic characteristic. And the method is used for the construction of streamline surface. After this, the construction method of wing ruled surface is investigated by use of Catmull-Clark subdivision. Then, the wing shape expressed by the way is optimized by using a special hybrid genetic algorithm. The aerodynamic optimization process includes inverse design and optimal design.