Coupled Analysis Of Thermal Protection And Thermal Control Of Hypersonic Vehicles

The hypersonic aircraft has the high military value and potential economic value,which can hit targets at great distances with precision and reduce the hit time to tens of minutes.Hypersonic aircrafts are facing severe thermal environment,which hinders their development.It is a developing trend in hypersonic field to seek a fast and effective method for the integrated analysis of thermal protection and thermal control of cabin system.Based on thermal environment in instrument compartment cabin of hypersonic aircraft as a benchmark,taking the heat insulation layer and the instrument cabin system as the research object,an integrated simulation method for thermal protection and thermal control of the hypersonic aircraft was carried out,the thermal network model of the hypersonic aircraft was established,and the simulation analysis of thermal environment in instrument cabin of the hypersonic aircraft under different working conditions was carried out.The main research contents are as follows:First,the formation mechanism of thermal environment in instrument cabin of the hypersonic aircraft was explored for heat generation and transmission.The basic principles of thermal analysis,the mathematical expressions involved and the basic control equations,as well as the calculation principles and control equations of the thermal network method are explored.Second,under the different heat transfer modes,based on SINDA/FLUINT software and FLUENT software,the integrated simulation of the heat insulation layer and thermal environment of cabin system was carried out,the calculation difference of four different working conditions was analyzed,and the proportion of convection heat transfer and radiation heat transfer in coupled heat transfer was investigated.an integrated simulation method for thermal protection and thermal control of the hypersonic aircraft was carried outAgain,the calculation method of aerodynamic thermal boundary was explored,the grid rationality verification of heat insulation layer was carried out.According to the structural characteristics of the hypersonic aircraft,the 3D geometric model was established and simplified,the grid division and grid independence verification were carried out,and the thermal network model of the hypersonic aircraft was established.Finally,the 3D dynamic simulation of thermal environment in the cabin was carried,the temperature distribution of key parts was obtained,the temperature environment in the cabin was evaluated,and various factors affecting the thermal environment were analyzed.The characteristics of pressure were studied,the influenceof pressure change in the cabin on the temperature distribution was analyzed,an the characteristics of emissivity were studied,the influence of the change of emissivity on the temperature distribution in the cabin was analyzed,and the infrared radiation simulation was carried out,and the infrared radiation intensity distribution was calculation.