Study On Aerodynamic Thermal Calculation And Thermal Protection Numerical Simulation Of Hypersonic Vehicle

Hypersonic technology is the third revolutionary technology in the history of aviation after propellers and jet propulsion.The hypersonic vehicle category includes space shuttles,manned spacecraft,rapid strike capability,global strike capability and destructive power.The development of hypersonic weapons is comparable to nonconventional weapons.The hypersonic vehicle is characterized by very high flight speed.One of the criteria for determining hypersonic flow is whether the Mach number of free flow exceeds 5.Its high mobility,rapid strike capability and long range precision strike make it a weapon that countries around the world are competing to develop.However,the intense aerodynamic heating makes the surface and interior of the vehicle extremely hot,especially in the front edge stops and wing edges,as well as the tail of the vehicle.These will have a major impact on whether the vehicle’s internal components work properly.Therefore,the thermal protection design of aircraft becomes very important for the safety performance of aircraft.The main research contents of this paper: Firstly,the effect of different Mach number,flight time and simulation results is explored by numerical simulation.Then,the convection heat transfer coefficient and the mainstream temperature of the outflow field are taken as the third boundary condition,the calculation method of external coupling heat transfer is adopted,and the heat transfer inside the aircraft is studied under the condition of heating protective material on the surface of the aircraft,and the importance of heat protection to the aircraft is explored.The innovation of this paper is to use the internal and external coupling heat transfer calculation method to calculate the internal heat transfer of the aircraft.The aerodynamic convection heat transfer coefficient and adiabatic temperature of the entire vehicle are calculated by the aerodynamic convection heat transfer coefficient and adiabatic temperature on the exterior surface of the vehicle.The main conclusions of this paper are:(1)The faster the flight speed,the more severe the thermal conditions,the most severe the thermal phenomena in the conical part of the nose,the higher the temperature in the aft flow field of the aircraft,the highest the temperature at the stopping point,and the further along the axis from the stopping point,the lower the temperature value.(2)With the increase of flight time,the thermal phenomenon is most serious in the conical part of the nose,and there is a higher temperature in the aft flow field.After six seconds,the outflow field temperature of the craft stabilized.(3)The calculation method of heat transfer in the inner structure of the aircraft is verified by solving the heat transfer problem of three structural solid regions and comparing with the software.The results show that the method can simulate the heat conduction of solid area under three kinds of boundary conditions.(4)After coating the aircraft surface with sic,porous material and metallic aluminum,the thermal protection of the aircraft can be effectively increased,the heat flow rate of aerodynamic heat loading to the aircraft surface can be reduced,and the heat transfer to the interior of the aircraft can be effectively prevented.