高焓湍流边界层直接数值模拟与湍流模型改进研究

With the further increase of hypersonic vehicle velocity, the coupling problem of high temperature chemical reaction and turbulence will become more and more prominent. The direct numerical simulation (DNS) of the turbulent boundary layer under the conditions of high-enthalpy flow and low-enthalpy flow is carried out respectively, and the physical quantities such as turbulent mean quantity, turbulent kinetic energy generation term and turbulent friction resistance coefficient are compared with the SST turbulence model. The preliminary results show that under the condition of low-enthalpy flow, the turbulent kinetic energy, turbulent viscosity coefficient and turbulent friction coefficient predicted by SST turbulence model are all higher than those calculated by DNS due to the influence of chemical reaction under high-enthalpy condition. Therefore, the SST turbulence model under high-enthalpy flow conditions is modified, and a temperature limiter is added to the turbulent kinetic energy generation term of k equation. The improved results are in good agreement with the calculated values of DNS.