Research On A Fire-fighting Shell For Towers

Fire fighting for towers was highly regarded as a cosmopolitan problem. Fire-fighting shell is a fire extinguisher aimed at fire fighting for towers, nowadays a series of fire extinguishers have been manufactured all of the world. Aiming at design a new fire-fighting shell, which was launched by pneumatic fire fighting cannon, could measure the temperature of fire scene autonomously after entered into it, and explored intelligently, then extinguisher dispersed above the fire scene, thus, the optimal fire fighting effect could be fulfilled.This thesis discussed the characteristics and developing situation of fire-fighting shell. The system design for the shell was focused on the structure and electronic fuze control system, based on the working characteristic and demand for performance of the fire-fighting shell. This thesis further discussed the extent to endure different load when the shell was launched, meanwhile analyzed the launching security for key parts.This thesis had a research of external trajectory and inner trajectory, because the characteristics of ballistics were related to the flight performance of the shell and the fire control system. The mathematical model of inner trajectory of the shell was established after analyzed the distribute law of inside pressure. The mathematical model of external trajectory in conditions of air resistance was established and the correction methods were provided at the same time. On this basis the external trajectory database was constructed.Whether the shell can penetrate the towers'glasses or not and the shell fluctuate during flight affect the posterior works and the final results. The material origin structure model was chose, the processes of the shell penetrate glasses were simulated under different situations, and combined the simulation result of ANSYS/LS-DYNA software with each unit of external trajectory as the reference for launching control.Finally, the flight performance for the shell was analyzed, the stress and moment of force during the flight was studied, the aerodynamic characteristics parameters were calculated, the flight stability was studied via the shell stability reserves and swing features and the result showed that the shell can fly steadily.