Research On Environment Detect And Safety Control Technology Of Underwater Conventional Ammunition Fuze

The complexity of modern warfare requires corresponding arms and weaponry. Our vast territorial waters, constantly maritime disputes with neighboring countries, the risk of armed conflict at sea, made vigorously develop the Navy and naval weaponry significant and very urgent. Small and medium calibre ammunition and weapons system using in water is one of current navy Special Forces equipment development direction. Compared with onshore ammunition fuze, underwater ammunition fuze research is weak, and the existing research has been focused on underwater target detection and recognition technology. Because of low recoil force and non-rotation characteristics of such ammunition as underwater rockets, there are many technical problems of fuze design especially environment sensitive and safety control. Solve the key technologies of the fuze system design and safety control of underwater conventional ammunition, has important practical significance for improving the weak status of the domestic underwater ammunition fuze safety control, expanding the fuze technology applications space, promoting the development of underwater conventional ammunition fuzes and improving our underwater weapons and equipment level.In this thesis, taking an underwater rocket fuze as the research object, according to the work course and the general requirements of fuze system, analysed available environmental information and determined using ballistic pressure and fluid power as the environmental incentive, achieve fuze environment sensitive and safety control with the pressure sensor and turbine mechanism. Difficult issues and key technology in the design of the fuze system was analysed.To obtain the function relationship of the fuze turbine rotational speed with the projectile velocity, and lay a foundation for optimal design of fuze turbine parameters, the turbine rotation mathematical model of underwater ammunition fuzes was established. The model takes into account the fluid viscosity, and established a quantitative relationship between the turbine structure parameters and dynamic performance, which does not depend on empirical coefficients obtained by tests. Since the flat-head projectile has good flight stability, analyzed the flow losses, when there’s no deflector in the head face of the turbine hub. Blade inlet velocity correction method was proposed, considering the boundary layer and the boundary layer separation. In addition, the turbine rotation speed approximate calculation theory method was studied in the case of a small angle of attack, by analyzing correspondence relationship of the incident angle of the fluid, boundary layer thickness and the inlet velocity distribution in a round of turbine blades.Pressure sensor type, parameters, the way of power supply and other issues have been compared and analysed. The projectile body pressure data at42cases of different angle of attack, different water depths and different speeds, was calculated by numerical methods, the optimal choice of strategy for selecting sensor installation location was present, and the sensor installation position was optimized. The key parameters of the rotation speed measurement system were designed and the error of different speed measurement methods was analysed. Based on the optimization theory, proposed fuze turbine parameter nonlinear optimization design processes and methods to solve experiential design and experimental design defects of the fuze turbine parameters, improve design efficiency and quality. Target aims to that projectile velocity-turbine speed has the best linearity, the fuze turbine parameters were optimized designed.The underlying theory and the model of the two-phase flow of underwater ammunition CFD technology were introduced. Considering the high-speed flow, rotating flow field and cavitation, fuze turbine three-dimensional flow field numerical simulation method was proposed. The applicability of Schnerr-sauer cavitation model and the Zwart-gerber-belamri cavitation model of underwater ammunition fuze turbine flow field numerical simulation was compared. Using the viscous fluid CFD technology, calculated the fuze turbine rotational speed in the case of the zero angle of attack and a small angle of attack, analysed the the pressure distribution of fuze head, the force of turbine in the axial direction and deformation of the turbine blade.Cavitation inception and its influencing factors were discussed. Cavitation influences on the hydrodynamic characteristics, as well as the general guidelines of the cavitation test were studied. The turbine institutions influences on the consistency of underwater ammunition ballistics and projectile stability were analyzed theoretically. Based on calculated results by numerical methods, turbine institutions influences on projectile head drag coefficient, center of pressure, pitching moment and pitching moment coefficient were studied. The range and stability differences of projectile with turbine and without turbine were quantitatively analyzed.Turbine mechanism and fuze control circuit were designed according to the system requirements, developed the fuze system principle prototype and conducted static tests and the water tunnel simulation tests. The test results show that the fuze design is feasible. The correctness of the turbine rotation mathematical models and parameter optimization design method of underwater ammunition fuze was verified. The fuze system design methods, theoretical models and numerical simulation technology, have a high reference value for the fuze system design and safety control of underwater conventional ammunition.