Aerodynamic And Transient Temperature Analysis Of Mechanically-deployed Entry Decelerator

Semi-rigid mechanically-deployed entry decelerator has broad application prospect for its advantages of less dimension restriction by rocket fairing envelope,higher efficiency in payload carrying,and better effect in aerodynamic deceleration.Compared with the traditional entry deceleration technology,the mechanically-deployed entry decelerator has the notable characteristics of light weight,small volume and large payload.It has wide application prospects in the future deep space exploration field.In this paper,the aerodynamic characteristics,structural stress characteristics and transient temperature field of TPS thermal protective layer are analyzed by numerical analysis.The flow field of different Mach numbers and attack angles are simulated and aerodynamic forces are analyzed by using computational fluid dynamics method in this paper.First,the flow field analysis model of the decelerator is established,and the correctness of the numerical analysis model is verified by comparing with the experimental data.Then the model is used to analyze the subsonic velocity and the aerodynamic characteristics of the supersonic flow field in the reentry of the reducer.The effects of different Mach number,different angle of attack and other factors on the aerodynamic parameters such as re-entry and deceleration effect,aerodynamic drag,and temperature distribution were investigated.Ansys finite element software was used to analyze the structural static and dynamics of the mechanically-expanded pneumatic reducer.First,the three-dimensional model of the expansion type pneumatic decelerator is established by using the three-dimensional CAD.Then the unidirectional flow-solid coupling method is used to analyze the structural deformation and stress characteristics of the reducer under the initial pretightening force and aerodynamic load.Subsequently,the analysis method of the natural vibration characteristics of the structure considering aerodynamic load is studied,and the influence of aerodynamic load on the inherent characteristics of the reducer structure is emphatically studied.Subsequently,the analysis methods for the natural vibration characteristics of the structure considering the aerodynamic loads were studied.The influence of the aerodynamic load on the inherent characteristics of the reducer is emphatically studied.In view of the heat protection problem of the aerodynamic drag surface of the expansion reducer.In this paper,the composition scheme of the thermal protection system of the expansion reducer is first studied.Then the transient temperature response of the thermal protection system of the reducer under the action of aerodynamic thermal load is analyzed by the flow-thermal coupling method.The influence of the material density,thermal conductivity coefficient and specific heat capacity of the heat shield layer on the thermal protection performance of the thermal protection system is emphatically analyzed.The above research can help the material selection and structure design of the heat protection system of the reducer.