Aerodynamic Design for an Inflatable Reentry and Descent Decelerator

Aerodynamic deceleration is one of the key technologies for aerospace vehicles.Inflatable airbag deceleration concept uses high-strength flexible fabric,thermal protection coating and gas generator to form its speed breaking system,the functions of teat protection,deceleration and landing shock absorption are integrated.Because of light-weighted,low cost,high reliability and wide applicability,inflatable airbag technique is beneficial to vehicle aerodynamic deceleration and aerothermal protection distinctively.Based on a deceleration requirement hypothesis of a hitchhiking device,forward and backward airbag are designed to satisfy the drag demand,the aerodynamic characteristics are predicted and analyzed using NS equation solver and engineering method,consequently the backward one is confirmed because of its better stability.The deceleration effect is simulated coupling 6-D trajectory with aerodynamics prediction method,the heat flux,the temperature of the inner and outer coating surfaces,the stress,the heat stress and corresponding strain are investigated,and finally the flight behavior deduced by the uncertainty of separation release condition is discussed.The investigation of introductory wind tunnel tests and theoretical analyses indicates that the inflatable airbag concept is one of the feasible choices for vehicle deceleration,and worth to be investigated further in the future.