Research Of Numerical Calculation Methods Based On Multi-vibrational Temperature Model In High-temperature Conditions

In order to study thermo-chemical nonequilibrium phenomena of high-temperature gas flow around hypersonic vehicles,this thesis summarizes the previous theoretical research results about two-temperature model.Based on the control equations,various related models and numerical simulation methods,the numerical calculation of multi-vibrational temperature model for high-temperature gas flow is established.In addition,the multi-vibrational temperature model was validated by example verification.And the effect of different temperature models on the numerical simulation of high-temperature gas effects was studied.First of all,the two-temperature model calculation verification of high temperature gas flow was carried out.The Japanese reentry vehicle OREX is selected as the research object,and the convergence analysis of the mesh in numerical simulation of high temperature gas effect is carried out.It is found that using the Reynolds number of wall mesh as the criterion of grid selection is more regular.Furthermore,by applying the grid selection criteria,the headspace of the Space Shuttle configuration is designed.The thermodynamic non-equilibrium two-temperature model and the ideal gas model are used to simulate the head flow field.And the influence of flow field structure and surface heat flux of Aircraft was studied.Secondly,the multi-vibrational temperature model of hypersonic vehicle is established,and numerical simulation methods are studied.Based on the two-dimensional axisymmetric NS equations,the multi-vibration temperature model was constructed by combining the thermodynamic model,transport model,chemical reaction model,the relevant equations derived and relaxation models of energy.In order to reduce the difficulty of the study,the simplification of the model is carried out on the basis of the existing literatures.Whether this hypothesis is reasonable or not needs further study.The main numerical calculation methods include: the second-order central difference scheme of viscous term,the AUSMPW scheme for convective term,and the implicit method of LUSGS.In the MUSCL interpolation calculation,the different limiters for comparative is studied in order to suppress the numerical oscillation.Thirdly,the multi-vibrational temperature model is used to calculate the standard test results.The results are in good agreement with the results of the literature,and the correctness of the multi-vibration temperature model is verified.In the numerical simulation results,most of the physical quantities are calculated correctly,but the temperature of micro-component vibration is inconsistent with the general law.It can be concluded that numerical dissipation causes of the phenomenon.At last,the effect on the numerical simulation results of high-temperature gas effect is analyzed by comparing the results of multi-vibration temperature model and two-temperature model.The results show that there is no significant difference between the two temperature models in the calculation of the flow field structure,but there are significant differences in the mass fraction distribution,the component vibration temperature and the electron number density of each component,indicating that the multi-vibrational temperature model can describe the high temperature Gas effect elaborately.