Multi-disciplinary Optimization Design Of Air-breathing Hypersonic Vehicle With Airframe/engine Integration

Hypersonic vehicle has been the hotspot of strategic and tactical competition of the world's major aviation and space powers at present, for its high flight speed, good mobility, long-distance strike capacity and so on. The airframe and engine of hypersonic vehicle are highly integrated, which brings the result that aerodynamic discipline and propulsion discipline have a crucial influence on the overall performance of hypersonic vehicle. Only by taking a full consideration of the strong coupling effect between airframe and engine, global optimal design concept can be obtained. In this thesis, hypersonic vehicle is taken as research subjects, by introducing Multi-disciplinary Design Optimization(MDO), the airframe/engine integration design issues and MDO methodology of hypersonic vehicle are studied comprehensively by means of theoretical analysis and numerical simulation. The main research is carried out in the following aspects:Firstly, by taking a full consideration of the strong coupling effect between airframe and engine, integrated design methodology and parametric modeling method of hypersonic vehicle are proposed and studied systemically. Besides, combining with the characteristics of all the target disciplines involved in this thesis, some reasonable shape parameters of hypersonic vehicle is proposed as the design variables of the optimization problem.Secondly, for each target discipline of hypersonic vehicle involved in this thesis, the creation process of performance analysis model is discussed in more details. Furthermore, a reasonable performance parameter of each target discipline is also put forward to evaluate the target discipline. The proposed performance parameter is regarded as design objective of the optimization problem.Then, based on the foregoing established integrated design methodology and target discipline performance analysis models, four single-objective optimization models and one multi-objectives optimization model are established. The optimal designs obtained by these optimization models are much better than the original design. Multi-level optimization method is introduced in forebody/inlet optimization design, the result shows that multi-level optimization method has a great advantage in optimization design.Lastly, one optimal hypersonic vehicle configuration is chosen from the Pareto solution results of multi-objectives optimization model to do a 3d numerical simulation. Moreover, a detailed analysis of flow field is carried out, and then a performance variation of each target discipline of hypersonic vehicle is obtained. By making a contrast of each target discipline of several hypersonic vehicle cases between 2d and 3d configuration, it proves that the optimal results obtained under 2d configuration have a strong instruction in 3d hypersonic vehicle design.