Study Of Thermal Response And Protection For Waverider Structure

Hypersonic vehicle technology, for its highly scientific and technological frontier nature and great strategic application value, is favored by all. Currently, major mechanical problems of aviation and aerospace have been listed in the Outline of National Long-and Mid-term Science and Technology Development Plan, which makes some technical problems concerning the development of hypersonic vehicle appear more prominent. Facing with the tendency of integration and fusion of aviation and aerospace technology and generalization of aerospace flying vehicle and spacialization of general flying vehicle in the future, this dissertation conducts the following research relying on the masterstroke of the development of hypersonic air-breathing vehicle, selecting waverider as the research object, centering on the issues such as design and optimization of waverider, prediction of wall heating flux, response of structural aerodynamic heating and thermal protection:Firstly, based on the theory of conical flow field, with shock angle, semi-spanwise angle, expansion angle, length-to-span ratio and function coefficient as design control parameters, cone-derived waverider configuration is generated under conditions of mach number 6 and 30km high atmosphere. On the basis of the analysis of the effect of the design control parameters on the performance of the lift-to-drag ratio of the waverider configuration, volume efficiency and etc., complex method is introduced to optimize and process the matching of lift to weight and top surface isentropic expansion of the generated waverider and the optimized shape of waverider is obtained under the design condition.Secondly, on the basis of the analysis of the thermal protection effect of blunt body structure, taking the generated waverider configuration as the research object, the sharp leading edge, which is the most serious aerodynamic heating area, is blunted. Through numerical simulation characteristics of flow over waverider configuration and the aerodynamic parameters near the wall under the flying state from the designed points are obtained. In combination with the engineering method, the heating flux caused by aerodynamic heating of the waverider configuration wall is predicted.Thirdly, the dissertation analyzes the fluid structure interaction of leading edge of the waverider configuration, the most serious aerodynamic heating area, studies the deformation of the leading edge of the waverider in the function of flow impact and aerodynamic heating and analyzes the interaction effect from the structural deformation to the flow field. The distribution of structural temperature field and thermal stress field is also inspected. A preliminary understanding of the response to flow impact and aerodynamic heating response is achieved, providing certain reference for the design of structural thermal protection.Finally, combined with specific experiment, the dissertation studies the issue of opposing jet thermal protection and its engineering application, analyzes the mechanism of reverse opposing jet thermal protection and the characteristics of the oscillations of the flow field after the interference wave and studies the effect of the stability of reverse opposing jet and the mainstream of flow field on thermal protection. Measures of opposing jet thermal protection are adopted for the sharp leading edge of the waverider, the most serious aerodynamic heating area. The numerical simulation verified the thermal protection effect of opposing jet thermal protection for the sharp leading edge structure.To sum up, taking hypersonic waverider for example, the dissertation conducts a comparatively systematic research on the appearance design, aerodynamic heating prediction, structural response and thermal protection. However, studies on the various researches on the work are still weak and have many shortcomings. It is expected that the dissertation can provide certain reference for project design problem.