Study On The Preprocessing Of Rapid Computation Of Aerodynamic Heating For Hypersonic Aircrafts

As CAD is applied widely in engineering, the method that converts the data, which define geometric configuration outputted by CAD software, to the data, which are required by CFD, is a problem that needs to be solved urgently. Combined with the team program"study on rapid computation of aerodynamic heating for hypersonic aircrafts based on IGES", this thesis studies several significant questions of the preprocessing which is one of the crucial techniques in the program.Firstly, the development and actuality about the preprocessing technique for complex configuration are analyzed systematically. On this basis, the research subject is confirmed. This paper presents a method how to get the useful data from an IGES file and do preconditioning with the data.The whole organizational structure of IGES files, the function of each segment and their relations are studied. The data rule of geometrical information in IGES is analyzed. Then the appropriate data memory structure is established, and the method how to get the useful data from an IGES file is given. On this basis, the IGES data interface is designed. The data in IGES file could be extracted and transformed.On the basis of analyzing the mathematics theory and geometry definition about NURBS surface, the discrete reconstruction of common surface models is realized, and the algorithms for the intersection between surface and plane are given. Based on the geometric operation of the data information, this paper makes a pilot study about the methods of the grid generation for an aircraft according to the characteristic of the flow field for hypersonic aircrafts and the request of the numerical simulation.On the whole, a method that extracts and deals with useful data from an IGES file is given in this paper. Based on the data of certain aircraft model, surface reconstruction, geometry section and grid generation are accomplished. The result indicates that the method solves the problem that converts the data, which define geometric configuration outputted by CAD software, to the data, which are required by CFD. For the aircraft configuration design, this method is viable and has wide engineering application domain. The work in this paper is a significant part of"rapid computation system for hypersonic aerodynamic heating".