The Research On Numerical Simulation Of Radiation Heating Characteristics In The Hypersonic Flow Field

In particular,the accurate prediction of the aerodynamic heat of reentry flow field in the hypersonic flow field has played an extremely important theoretical role in the design of the thermal protection system,the optimization of the shape design,and the optimization of the flight track.When the flight speed of vehicles in the atmosphere reaches hypersonic speed,the flow field near the vehicles side has a strong thermo-chemical nonequilibrium effect,and at the same time,multi-species air in the area between the surface of its head and the shock layer has strong thermal radiation,radiation heating and aerodynamic heating heat the surface of the vehicles jointly.The study on the phenomenon of radiation heating helps to dig out the theoretical mechanism of radiative heat transfer which further guides engineering design effectively.Therefore,this paper uses the numerical simulations to make a research on thermo-chemical nonequilibrium flow,radiative transfer and thermal radiation in the flow field.Firstly,it was the surveys in this paper which include the research status of numerical solutions of thermo-chemical nonequilibrium flow,radiative transfer and radiant characteristics.And the entire theoretical system used in this paper was obtained after comparison,including derived the finite volume method which has been separately adopted for solving governing equations of flow and radiative transfer equation,and the corresponding calculation programs were compiled.And the accuracy verifications of the numerical calculation programs for thermo-chemical nonequilibrium flow and radiative transfer were carried out.The results obtained in this paper were consistent with the literature which effectively proves the theoretical method of this paper and the thermo-chemical nonequilibrium flow field characteristics was emphatically analyzed from multiple dimensions.Secondly,the principle and mechanism of radiant characteristics of gases under the conditions of medium-high temperature and high temperature was expounded and the Line-by-line method adopted for this paper was derived,and the corresponding refined calculation programs for radiant characteristics of gases were compiled which were verified by relevant examples,and the effect of different calculation parameters on the results.The improved engineering calculation method and process for radiant characteristics of gases under the conditions of medium-high temperature and high temperature was gave and derived and the corresponding calculation programs were compiled which were verified.The research results showed both the truncated wave number and wave number resolution have a greater impact,and the results obtained in this paper were consistent with the literature which effectively proves the theoretical calculation method of this paper and lays the foundation for numerical simulation of radiative transfer.Finally,the influence law of different factors on radiative transfer was studied and the accuracy verifications of the numerical calculation programs for thermal radiation were carried out.The results obtained in this paper were consistent with reality and engineering results which effectively proves the theoretical method of this paper and the correlation between thermo-chemical nonequilibrium characteristics and radiation heating characteristics was studied by one of the flight statuses in flow field.The numerical simulations of the thermo-chemical nonequilibrium flow field and thermal radiation of the typical vehicles based on the typical trajectory data were carried out,and the changes of the stagnation-point convective and radiative heat flux and their proportion were studied.The research results showed that there was a peak value in both the radiative heat flux value and its proportion,but radiative heat flux has a significant cooling effect on the convective heat flux.The influence law of different factors on the radiative heat flux in the hypersonic flow field was studied by the case of stagnation-point,and the research results showed that all factors except the catalytic conditions of surface all have a greater impact.