Heat Flux Distribution Research Of Hypersonic Blunt Body Vehicle

With the improvement of Mach number,hypersonic flight vehicle aerodynamic heating is more and more serious,requirements for materials and equipment become increasingly higher.Stagnation point is the most severe aerodynamic heating position,Only to accurate calculation of heat flux,it can provide reliable basis for the design of hypersonic flight vehicle thermal protection.Mainly aimed at Mach number 4.5hypersonic blunt body aircraft,In this paper,we comprehensively research on the calculation of hypersonic blunt body aircraft heat,by solving the Navier-Stokes equations.we investigate the wall heat distribution in the different wall boundary conditions.According to the characteristics of the flow,We analyzed the lack of the results only considering the thermal conditions,And proposed the calculation of heat flux with the convective heat transfer formula it is more reasonable and conform to the actual flight conditions.And also compares the calculation result of numerical calculation and engineering.The detail conclusions are as follow:(1)Through the Fourier solution,to calculate hypersonic blunt body aircraft stagnation of heat flux with Mach number 4.5,the peak of wall heat flux is near stagnation point,which betray the laws of physics.This shows that the Fourier heat conduction is not suitable,the reason is we ignore the gas flow near the stagnation point.(2)At zero angle of attack and the small angle of attack hypersonic blunt body aircraft,through the convection heat transfer formula,we found that the stagnation point heat flux is the largest when the angle of attack is zero,At angle of attack,the windward side of the heat flux is significantly higher than that of other sides' heat flux.On the windward side and the leeward side's surface,profiles with different peak heat flux move to the front of the center of sphere.The maxmium of heat flow appears near the stagnation point position,Heat flux maximum peak appeared in the windward surface corresponding stagnation point position.With the current increase of the Mach number and angle of attack,the stagnation point heat flux peak appears more obvious.At angle of attack,stagnation temperature is at the maximum lift,at the same time,windward surface temperature rise is larger than the leeward side's.(3)With the result of the engineering calculation,we found that the use of convective heat transfer formula to calculate the stationary point heat flux and the stagnation point heat flux,and the qualitatively consistent with the result of engineering calculation formula,but the quantitative has bigger difference than engineering calculation formula.This also put forward the demand for a further study.