Multi-disciplinary Optimization Design Of Hypersonic Vehicle Based On Adaptive Surrogate Model

The surrogate model method has attracted much attention in the field of optimization due to its effective reduction of computing time.But as the dimension of design variables increases,the number of samples needed to construct the surrogate model will increasing exponentially,meanwhile the local precision of the model is difficult to be improved.In order to improve the efficiency of high precision optimization method in high dimensional design space,an adaptive surrogate model method which based on moving search space is proposed in this paper.This method is applied to the optimization design of airfoil/wing and hypersonic vehicle,and a good optimization result is obtained.Firstly,the principle and modeling process of a variety of surrogate models are expounded in this paper and their fitting accuracy are compared.The advantages and disadvantages of the classical surrogate model method are analyzed,and taking a number of test functions as example,the qualitative relationship between the number of samples,the dimension of design variables and the accuracy of fitting is statistically analyzed.Thus,an adaptive method is proposed that the search space moves with the local optimum.By taking the model refinement method of selected points as a breakthrough,the automatic partition and classification approximation of search space can be realized.Secondly,for verifying accuracy and validity of the adaptive method,typical functions and airfoil/wing example are tested in this paper.Test results show that: compared with ordinary surrogate-based optimization method,this method can not only save the total number of samples required,but also improve the search efficiency and accuracy.The good drag reduction effect of airfoil/wing shows that this method is of practical value for aerodynamic optimization design.Lastly,the parameterized modeling method of the X-43 A lift body hypersonic vehicle is studied by considering the multi-disciplinary coupling effect of airframe/engine integration;Four disciplines analysis model,i.e.the performance of engine propulsion system,the aerodynamic performance of the forebody/inlet,aerodynamic force and aerodynamic heating,are established and the appropriate objective parameters are selected;By using the optimization method developed in this paper,the problem of single/multi-disciplinary optimization design for hypersonic vehicle is solved effectively.