Numerical Analysis Of Aerodynamic And Structural Mechanical Characteristics Of Inflatable Aerodynamic Decelerator

The simulation object is the Inflatable Aerodynamic Decelerator(IAD)matching to the entry capsule of Mars Science Laboratory(MSL)in this paper.The aerodynamic characteristics and the structure mechanical characteristics of the IAD are simulated and analyzed.First of all,the experiment made by LaRC is taken as a reference to verify the accuracy of the numerical method used in this paper.Based on this,the process of IAD entrying the atmosphere at supersonic is simulated and the aerodynamic characteristics of the IAD in supersonic flow field is analyzed.It’s found that,when the angle of attack is zero,the flow field around IAD is symmetrically distributed.With the increase of the velocity,the stagnation pressure and stagnation temperature in front of IAD increase gradually.The drag coefficient of IAD also increases gradually.When the angle of attack isn’t zero,the flow field around IAD is asymmetrically distributed.With the increase of the angle of attack,the stagnation point in front of IAD gradually moves from center to upwind direction gradually.The drag coefficient of IAD decreases gradually,while the lift coefficient and negative pitching moment of IAD increase obviously.Secondly,structural analysis and modal analysis of IAD are simulated based on Finite Element Method(FEM).The influence of the material thickness,material elasticity modulus and aerodynamic pressure made on the structural mechanical characteristics of IAD is studied.It’s found that,the material thickness,material elasticity modulus and aerodynamic pressure has no effect on the deformation and stress distribution on the surface of IAD.Increase of the aerodynamic pressure can lead to the deformation on the surface of IAD increase,while increase of the material thickness and material elastic modulus can lead to the deformation on the surface of IAD decrease.The vibration mode of the IAD is mainly manifested as the swing,distortion and local deformation of the inflatable ring.The natural frequency of modal vibration increases with the increase of order,and the increase of material thickness,material elastic modulus and aerodynamic pressure will lead to the natural frequency of modal vibration increase.