Theoretical And Experimental Research On Hot Gas Secondary Injection For Solid Rocket Motor

Focusing on Hot Gas Secondary Injection Thrust Vector Control (HGSITVC) technology for Solid Rocket Motor (SRM), starting from the analysis of flow control mechanism, through a study on the theoretical and experimental research on HGSITVC technology, this dissertation attempts to explore the technical approach to improve the performance of SRM HGSITVC system and thus provide theoretical as well as technical guidance for its research.Based on the analysis of working characteristics of HGSITVC system, experimental system of hot gas secondary injection motor is designed and tested successfully, which accumulates theoretical basis and practical experience for HGSITVC SRM. The experimental results show that the thrust vector control deflected angle is 7 degree, which proves that the efficiency of HGSITVC system is higher than that of liquid secondary injection thrust vector control system, obviously.The mathematical models suited for three-dimensional turbulent flow are constructed for the simulation of the main/secondary interaction flow filed in HGSITVC SRM. Complex shock wave structures and phenomena of flow are revealed from the numerical results. Comparison between the simulation results and the experimental ones approves the applicability of the simulating models and methods established in this dissertation. Besides qualitative analysis of thermal ablation appeared in experiment is carried out by dint of numerical simulation.Start-up and cutoff of SRM HGSITVC system are simulated numerically with three-dimensional unsteady flow model. The influence of hot gas bleeding and secondary injecting in transient process on internal flow filed and interior ballistic performance of SRM is investigated in order to clear about dynamic characteristics of the flow field. The results display that the unsteady characteristics have remarkable influence on flow field structures, flow parameters and system performance. Therefore, conclusions obtained above provide technical guidance for future research on HGSITVC system.The dissertation proposes performance evaluation index of SRM HGSITVC system and investigates systematically the influence law of different parameters on both main/secondary interaction flow field and performance of HGSITVC system through three-dimensional numerical simulation, hence information gained above provides theoretical foundation for active flow control of main/secondary interaction.Moreover, the dissertation gives the integrative numerical simulation model of inside and outside flow field for HGSITVC SRM and explores the main/secondary interactional flow field as well as the varying law of HGSITVC system performance, which provide important foundation for technical application of HGSITVC system.The new method combining three-dimensional numerical simulation of main/secondary interaction flow filed with response surface methodology based on partial orthogonal polynomial is applied successfully to optimize the performance of HGSITVC system. Design method for multi-index orthogonal test is introduced to analyze and optimize both the geometric parameters of HGSITVC system and secondary injection gas properties. All above solve the parameters optimization problem of HGSITVC system performance. And some meaningful result is derived, which shows the effectiveness of this new method.The research in this dissertation provides important guidance to the SRM HGSITVC system. The conclusions will promote the development of thrust vector control technology and expand the range of application to SRM. Therefore it is of great theoretical value as well as engineering practice meaning for active flow control technology and application.