Study On Fast Calculation Of Complex Shape Rocket Projectile Aerodynamic Heating Considering Transition Effect

Due to the strong compression of the gas in the boundary layer and intense friction between the wall,the hypersonic rockets have severe aerodynamic heating during the flight.In order to evaluate the surface aerodynamic heating of hypersonic rocket projectile effectively and accurately,considering the boundary layer transition and the numerical calculation of heat-protection layer on the surface of projectile.The algorithm is coupled to calculate the aerodynamic thermal parameters of the complex shape rockets and analyze the effects of the boundary layer transition on the object surface and the aerodynamic parameters.The coupling algorithm consists of three steps.Firstly,the numerical solution of non-viscid outflow is calculated by using the pure numerical method.The Euler equation is adopted as the governing equation.The spatial dispersion is based on Roe’s second-order windward dispersion based on finite volume.LU-SGS implicit scheme is used for time discretization.Secondly,in order to more accurately calculate the aerodynamic heating of the rocket surface,it is necessary to accurately calculate the streamline length of the surface of the projectile.In this paper,the streamline tracking algorithm is used to calculate the streamline length of the surface of the projectile.The flow lines of M6 wing,blunt cone and wing-body fuselage and post-processing software under the condition of flow are compared and analyzed,then the flow drawn by streamline and post-processing software is obtained.This paper verifies the correctness of the tracking streamline algorithm.Based on the streamline tracking algorithm,this paper verifies two criteria of smooth wall transition by two-dimensional flat plate,three-dimensional blunt cone and three-dimensional warhead.Wall Transition Criterion 1 fits better with experiment.Finally,the one-dimensional heat conduction hypothesis is used to neglect the contact thermal resistance between the thermal protection layer,and a simplified calculation model of the thermal protection layer is established.The heat flux obtained by the engineering algorithm is used as the boundary condition to solve the heat conduction differential equation,and the unsteady heat transfer process of the thermal protection layer is simulated.Firstly,based on the classic blunt cone TN-D5450 model of aerodynamic heating environment is calculated,then the calculation of the blunt cone surface heat flux and experimental results are compared,finding that the dynamic calculation of heat flux is agreed well with experimental data verifying the accuracy of the aerodynamic heating calculation method.Secondly,in order to accurately calculate the rocket aerodynamic heating,it is necessary to accurately calculate the projectile surface streamline length.This paper adopts Newton’s theory stream tracing algorithm calculation of projectile surface streamline length.In different flow conditions,the streamline of M6 wing,blunt cone and blended wing that postprocessed through software are compared to the streamline obtained by the flow stream tracing algorithm verifying the correctness of the streamline tracking algorithm.Thirdly,based on the streamline tracking algorithm,the two light-wall transition rules are validated by two-dimensional flat plate,three-dimensional blunt cone,and three-dimensional warheads.The result of the smooth wall transition criterion 1 is better than the experimental one.In this paper,the aerodynamic heating environment of hypersonic rockets is calculated.The aerodynamic heating calculation results are compared with two cases considering the boundary layer transition and the complete laminar flow.The effects of the height of the flow,the Mach number and the angle of attack on the rocket rotation are considered to analyze the influence law of aerodynamic heating.The results show that the aerodynamic heating calculation method used in this paper can predict the aerodynamic heating distribution of complex rocket surfaces quickly and accurately,at the same time the method can provide a reference for the hypersonic rocket aerodynamic heating protection.