壁面辐射平衡DSMC方法及其在双锥构型中应用

For high altitude long endurance hypersonic vehicle, the surface temperature is increased significantly due to aerodynamic heating. The pneumatic heating data obtained by ground wind tunnel tests and traditional DSMC simulation is obviously higher than flight observations, leading to conservative design of thermal protection systems. A wall boundary condition based on radiative equilibrium is studied and developed, in which the wall temperature is inversely calculated by the pneumatic heating flux and the temperature is used as the boundary condition of next time step calculation until it converges. Based on the boundary condition, the DSMC solver for axisymmetric configurations is developed and validated through the blunted cone computation. We focus on the double-cone configuration, and the numerical simulation of double-cone is carried out in condition of the shock wave wind tunnel test. Test cases show that the heat flux and pressure in constant temperature cold wall condition are consistent with those in the ground wind tunnel test. In two temperature boundary conditions, the peak pressure has the difference of 15.4%, but the difference of total aerodynamic coefficient is only 0.33%. Compared with the result in cold wall condition, the peak heat flux at the leading edge is reduced by about 50%, and that at the reattachment point is reduced by 66.67%. According to the results in two conditions, the range of surface heat flux can be given.