| Numercial aerodynamic optimization is an interdiscipline automatic design method via computational fluid dynamics and optimization theory. It can implement multi-objective optimization and multi-parameter combinatorial optimization with less dependency on designer's experience. However, numercial aerodynamic optimization design requires considerable flow field calculation accuracy and computing speed, it has not been developing so fast until recent years with the rapid advancement of computer technology.Fan/compressor design using numercial aerodynamic optimization focus on four key technologies: Fan/compressor blade passage flow field numerical method; Numerical optimization method with a good search capability; Parameterization description method of three-dimensional blade shape using Computer Aided Geometric Design Technology; The construction methodology of multi-objective function for aerodynamic performance. Estimated 30K LOC have been coded to implement the aforementioned critical technologies and based on these, the following research is carried out in detail:Firstly, fan/compressor flow field calculation procedure based on the distributed body force proposed by Denton is carried out in this thesis, and this method can shorten flow field computing time effectively compared to that based on Reynolds-averaged NS equations. The law of experience parameter setting is explored by NASA Rotor67 and Rotor37 examples. The accuracy of this procedure is verified by comparing the procedure calculation result to the NUMECA calculation results and experiment data.Secondly, an advanced genetic algorithm using Real-coded, adaptive operators, niching techniquesis at the basis of Simple Genetic Algorithm has improved the search efficiency and global optimization ability. Then this algorithm is paralleled on the LAN and server through winsock, multi-thread and Client-Server architecture to reduce the time-consuming of optimization.Thirdly, a fan/compressor blade parameterization method based on modification is studied including curved/swept stacking line, profile, meridional channel and chord length. In order to improve the optimization convergence rate, a multi-level parameterization algorithm is involved following Multi-Grid Method and Bezier recursive algorithm in this thesis. And corresponding relationships are set up between blade stacking line curved/swept, chord length and translation operation, rotating operation, zoom operation in CAGD. Fourthly, in the process of fan/compressor blade numercial aerodynamic optimization, the initial blade is necessary. Analysis and comparisons of revolving surface cascade and plane cascade give their differences, and then the revolving surface cascade is selected to design blade profile. At last, all profiles are stacked together on the radial to form initial blade.Finally, the software called OTMBPGA (Optimization of Turbomachinery Blades based on Parallel Genetic Algorithm) is integrated with Genetic Algorithm module, blade parameterization module, grid generation and flow field calculation module and objective fuction setting module. The data exchanges among those modules are convenient by using public memery. And every module is also independent, so it's easy to maintain, extend software function and program debugging. OTMBPGA has friendly user interface, the functionality of two-dimensional and three-dimensional blade parallel optimization, the capacity of post-processing and graphical display of optimization result. 2D and 3D blade optimization examples verify that the design of the blade with high aerodynamic performance using OTMBPGA are reliable and high-efficiency, it can save design cost and shorten design period.
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