Calculation Of Aerodynamic Heating And Temperature Field For Hypersonic Warhead Under Attack Angle

For the hypersonic field appeared "barrier", to accurately forecast the hypersonic missile aerodynamic heating and temperature field has become the key technology in the design of hypersonic warhead. In this thesis,the method coupled with numerical calculation of external aerodynamic algorithm and warhead thermal engineering internal structure heat transfer are adopted, for the rapid prediction of attack angle for hypersonic missile aerodynamic thermal environment. And research the aerodynamic heat transfer characteristics of the warhead with the basic configuration. The research results can provide technical support for the analysis of aerodynamic thermal characteristics, and provide a reference for the aerodynamic design of hypersonic warhead.On the base of Prandtl theory, the inviscid flow field outside the boundary layer of hypersonic warhead use the modified Newton theory and Prandtl Meyer formula to calculate pressure of warhead surface.Edge conditions for the boundary-layer solution are obtained from gas parameters after shock wave of the warhead with the constant entropy expansion method. Equivalent cone method and axial symmetry method is used to calculate the heat flux distribution which is based on empirical formula of heat flux in view of reference entropy. Consider warhead material properties, the non steady state heat conduction equations are discretized by finite volume method for calculation of internal temperature flied distribution. The heat flux calculation formula coupled engineering algorithm with numerical calculation for internal temperature field can predict surface heat flux distribution and temperature distribution of warhead at any time during hypersonic warhead aerodynamic heating process.First of all, a typical spherical cone warhead model is selected to validate the example and analysis the influence of angle of attack for aerodynamic thermal environment. And then according to the basic shape of the warhead, contrasting pointed cone, small blunt sphere cone and large blunt sphere cone warhead to analysis the effect of warhead front for aerodynamic heat. Comparing cone shape and curve revolving body shape to analysis the effect of warhead shape for aerodynamic heat. Finally, choosing a ball double cone warhead model to verify accuracy.Through comparison with experimental data, linear fitting to the inflection point region, analyzing the effect of inflection point shift for aerodynamic heat by comparing different inflection points of the aerodynamic heating environment of three kinds of spherical double cone warheads.Verification of typical spherical cone projectile illustrates the method can accurately predict the aerodynamic heat environment of ball cone and meet the needs of engineering design. The angle of attack makes the heat flux density of windward side far greater than the leeward and the isotherm of body surface and internal body tilt. Increasing the tip of the leading edge is equivalent to add a section of high temperature of in warhead parts and cause global heat flow and temperature rise. The cone part heat flux and temperature of curve swing type warhead increase faster and overall temperature rise is small. Based on linear fitting to heat flow of inflection point region, modified method can exactly predict the aerodynamic thermal environment of ball cone projectile. The inflection point forward leads the temperature of cone front part rise faster compared to cone rear part. Select the appropriate position of inflection point can reduce the maximum temperature of the warhead stagnation, help to improve the aerodynamic thermal environment.