The Engineering Method Of Aerodynamic Heating Over Projectiles' Head At Hypersonic Flow And Numerical Heat Transfer

The steady state conduction equation is discretized by using the finite volume method (FVM) in the unstructured grid. For the diffusion terms, the normal direction scalar and the tangent direction scalar were coupled iterated to meet the high precision demand. The programs have been complied by visual Fortran95.The mesh generation that come from Tecplot and GAMBIT are searched and ranged again by the code complied by C++.The engineering methods have been applied to calculate the heat flux of the spherically blunted cone on the condition of the standard atmosphere and the coming flow is on 5-8 Mach number. The basic formulas are Fay-Riddell balance boundary layer stagnation point heat flux formula and Lees' formula. There are two states to be considered here. One is the complete laminar boundary layer and the other is the boundary layer transition. The transition point is confirmed by Batt boundary layer transition criteria. The turbulent heating-rate expression is applied in the area of turbulence boundary layer. The transition region's heat flux is calculated with weighed average of laminar and turbulence heat transfer.Integrated with equivalence conical method, the influence of the angle of attack is considered in calculating the heat flux of the projectile's head in 3D situation. And another simplified method is applied for calculating laminar heat transfer over bodies at the same angle of attack as being mentioned. The result is compared with experiment and the equivalence conical method.The heat flux was linearizated as the third kind of boundary conditions and coupled with the numerical thermal conduction in the projectile's head. The temperature of the projectile's head is simulated. The result indicate that:turbulence boundary layer will enhance the heat conduction and the temperature of the surface will go up. The larger the angles of attack the bigger the heat flux over the surface on the windward, and the higher the temperature on the windward. But on the surface of the leeward, the trend is the opposite.