Numerical Research On The Hypersonic Thermal-Fluid-Structure Multiphysical Field

The aerodynamic heating prediction and thermal protection system design are important issues for researchers. When a hypersonic vehicle is flying at a high speed in the atmosphere, the temperature around the vehicle increases remarkably because of shock wave and viscous effect, causing the aerodynamic heating problem. Meanwhile, the great amount of heat flow resulting from aerodynamic heating transfer into the body structure in the form of heat conduction and radiation. The structure temperature increases and causes thermal stress and strain. So, This paper carries out the research of hypersonic aerodynamic heating numerical simulation and thermal-fluid-structure multi-physics coupling integration calculation technology.Firstly, it was the literature surveys in the paper which included the hypersonic aerodynamic heating calculations, unsteady calculation of multi-physics and a summary of existed research progress and research methods. Then the theory and simulation methods used for this paper were described, including the complete Navier-Stockes equation under the multi-component gas, numerical solution method based on structured grid finite volume method, and the initial conditions for the hypersonic flow, boundary conditions and the flow of initialization.Secondly, numerical simulation of the aero-thermal was carried out for a blunt cone shape double ellipsoid shape and aerospace plane. The numerical results of the performance of hypersonic vehicles showed the influence of different flight heights on the chemical reaction rate,the surface pressure distribution and heat flux distribution on the center line and the upper and lower surface of airfoil. It was revealed that the flight height impacted on the chemical reaction rate significantly as the air was thinner with the higher of altitude, and the thin air slows down the reaction. On the other hand, the flight altitude has no influence on the surface pressure coefficient distribution. Also, the influence of different flight speed and angle of attack on the aerodynamic heating were studied. The simulation results showed that both the flight speed and angle of attack affected the aerodynamic heating distribution.The numerical results were consistent with the literature, which verified the validity of the calculation and simulation method in this paper, and laid the foundation for the analysis of the coupled multi-physics field.Finally, the computing for the coupled multi-physics field and fluid-structure surface data transfer theory were introduced. Based on the hypersonic wind tunnel experiments of flow around a cylinder, the unsteady multi-physics coupling calculation was carried out at the Mach number 6.47. It was compared to the influences of multi-physics coupling in the flow field, structure temperature field, and structure stress field. The results showed that multi-physics coupling had a great impact on wall temperature,the structure temperature field and structure stress field.