| Thermal protection system(TPS) is a key technique of the high speed vehicles’ design and manufacture, which gets a great attention of researchers at home and abroad. On the base of full understanding to the existing TPS and technology, a new platelet nose-tip is proposed. It consists of a lot of platelets, which uses opposing jet TPS in the stationary point zone and transpiration cooling TPS in the other zone. These two methods of TPS are combined in order to realize the cooling of the full nose-tip.The present dissertation is about research of platelet nose-tip TPS for high speed vehicles. The numerical simulation mode of the flow field of hypersonic vehicle nose-tip is established, and which is proved to be effective by the comparison with experimental data. The complex hypersonic flowfield and wall heat flux are simulated and analyzed. The properties of attack angle for opposing jet TPS was discussed, the useful attach angle range of opposing jet TPS was obtained. When the attack angle reaches 9?, the heat flux on the windward generatrix is close to the maximal heat flux on the wall surface of the nose-tip without thermal protection system, thus the thermal protection is failure.Hypersonic aerothermal simulation method for high temperature thermochemical nonequilibrium flow is developed. When high temperature thermochemical nonequili-brium model is used, the temperature of the flow field is reduced. After the wave pressure and density is bigger than the calculation results of calorically perfect gas model. But the shock detached distance is smaller than the calculation results of calorically perfect gas model. In the research range of this paper, effect of high temperature thermochemical nonequilibrium can be ignored when the fligh Mach number is less or equal to six.A numerical study on the flow field of hypersonic vehicle platelet nose-tip and aerodynamic heating is congducted. The influence opposing jet and transpiration to the flow field parameters and heat flux distribution along the outer body surface is studied, and the cooling effect of the platelet nose-tip thermal protection system is also analyzed. The platelet nose-tip thermal protection system can effective to protect it, and reduce the heat flux of the structure. The Mach number of opposing jet is greater, the cooling effect for platelet nose-tip is better. The pressure and velocity of transpiration outlet have a little influence on the flow field of platelet nose-tip, which just change the flow field near the ooutlet. And it can reduce the wall heat flux of the platelet nose-tip.The structure of the platelet nose-tip is introduced in detail. And the heat process in it is simulated. Heat transfer analysis model of the platelet nose-tip solid structure is established. According to this calculation model, a heat transfer calculation Program of he platelet nose-tip solid structure is written. The temperature distribution of the nose-tip structure and the temperature change trend of the transpiration working medium along the radial deraction are obtained. Whether flow change or not change, the temperature of the nose-tip is lower with the increase of Ni or Nk. But temperature drop will increase when the total transpiration flow increases. In the research range of this paper, it can effectively control the temperature of the nose-tip structrure within 1000 K using the platelet nose-tip thermal protection system. So it can be for effective protection nose-tip structure.The thermal performance of platelet nose-tip structure has carried on the qualitative test research. The method of stress fastening molding is used process the platelet nose-tip structure, which is high production efficiency and low cost. The experimental nose-tip structure is made in this way, and it satisfy the requirement of experiment. The experimental results prove that the platelet nose-tip thermal protection system is effective. |
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