Research On The Techniques Of Precise Recovery System For The Controllable Parafoil Of Launch Vehicle Separate Bodies

This thesis presents a technical scheme for the accurate and nondestructive recovery of the launch vehicle separation system with a large controllable parafoil system.Parafoil and booster combination dynamic performance,parafoil aerodynamic characteristics,precise homing and landing methods,nondestructive landing technology,district planning control,explosive ejection process and large parachute friction mechanism were studied,some results have been achieved.1)The rocket booster recovery system and the large parafoil system are analyzed,and the scheme of using the large parafoil to accurately recover the booster is developed.The booster dispersion beyond parafoil homing capabilities,established the calculation model of point target and line target homing mode,the homing method adaptability are analyzed,put forward to reduce down multi target homing project area scattered,effectively solve the control problem of the landing area of booster.2)The six degree of freedom dynamics model is established,and the dynamic simulation of the parafoil booster assembly is carried out.Calculation method of dynamic performance of CFD improved the parafoil gas,the introduction of multi block structured grid and grid perturbation method to improve the efficiency of grid generation,making the grid and the airfoil leading edge cutting angle corresponding to the change cutting angle corresponding to the change of inlet distortion strategy,the development of the numerical solution of N-S equation is suitable for low-speed viscous flow calculation optimization method to achieve optimum design the parafoil aerodynamic performance.3)The precise homing,improved undamaged landing control method is proposed.Analysis of constraints of homing problem,proved the control and wind field change is the main factor influencing the landing precision.Put forward with terminal correction method and homing runway landing,landing and linear accurate pipeline control method.In this paper,the influence of wind field is analyzed,and the velocity decomposition method is proposed.The simulation results show that the method can effectively improve the landing accuracy.4)The first ejecting model is established considering the compressibility of parachute and extensibility of the flexible material,found that due to the compressibility of the parachute ejection process of thrust peak lag effect,flexible material to pack the elastic stress is obviously reduced.This paper studies the effect of explosive parameters,ejector geometry,material properties and pack packing density of ejection force,speed and force of ejection parachute,etc.This paper also analyzes the out-bag process of large parachute,first mathematical model of canopy friction is established,put forward the additional effect of high-speed movement is mainly caused by friction damage.The effects of packing density,friction velocity and material properties were analyzed,and the measures to control the friction effect are put forward.The research work of this paper has certain reference value for engineering development.