Multifield Coupling Simulation Analysis Of Aerodynamics And Structural Thermal Of Supersonic Long-Range Rocket

Long-range rockets have the characteristics of supersonic flight and strong penetration ability,and are widely used in modern warfare.At the same time,the high-speed flight causes the rocket pressure load and temperature load to increase,resulting in elastic deformation,and ultimately destroys the flight stability of the rocket and deviates from the trajectory.Therefore,it is necessary to study the influence of aerodynamic force and heat on the structure of rocket in the overall design of long-range rocket.In this paper,Computational Fluid Dynamics（CFD）and Computational Structural Dynamics（CSD）are used for coupling analysis.The structural change of a long-range rocket under thermal and mechanical conditions is calculated,and the influence of pressure load and temperature load on the flight attitude of rocket is analyzed.The thermal protection coating is set on the outer surface of the rocket to reduce the deformation caused by the increase of heat in the rocket flight,so that the rocket flight is more stable.Firstly,the model was established according to the structural parameters to separate the fluid and solid parts.The influence of different velocity and attack angle on lift coefficient,drag coefficient and pitching moment of rocket is calculated by CFD numerical simulation method.The results show that the attack angle of the rocket and the three groups of aerodynamic parameters show a positive correlation,and the aerodynamic environment of the rocket is more complex when it flies at large attack angle.Secondly,the boundary data of fluid domain and solid domain are established by using the calculated aerodynamic parameters of rocket,and the fluid-structure one-way and two-way coupling of the model is carried out.After calculation,the deformation and stress of rocket under two coupling modes are obtained,and the pressure center position of rocket with or without attack angle is obtained.Then,the pressure and temperature loads are imported to analyze the influence of pressure and temperature loads on structural deformation and stress.The calculation results show that the deformation and stress of rocket are greatly improved when the temperature load exists,indicating that the influence of temperature load on the flight attitude of rocket is higher than that of pressure load.Finally,PTFE was selected as the thermal coating material.The distribution of rocket deformation,stress and surface temperature after adding 1 mm and 1.5 mm thermal protection coatings was obtained respectively.The results show that the deformation of rocket decreases by 11 %,the stress decreases by 15 %,and the surface temperature decreases by 10 % in the velocity range of 1.5 Ma – 2.5 Ma.At the same time,it is found that the temperature difference between the upper and lower surfaces of the rocket decreases after the thermal coating is added at the attack angle,so that the deformation of the rocket decreases and the flight stability is improved.