Study On The Influence Of Fire On The Safety Of Ammunition In Ship’s Ammunition Compartment

After a long time of modernization development,military ships have reached a certain level of self-protection ability,but the ship’s ammunition cabin has always been the weak link of the ship.The practice has proved that the ammunition cabin fire in the naval battle leads to the internal ammunition explosion and the probability of sinking the ship is very high.This paper mainly studies the impact of fire on the safety of the projectile inside the ammunition cabin,which plays a certain reference role in the fire protection of the ammunition cabin of naval ships.The research status of ship fire and ammunition thermal vulnerability at home and abroad is analyzed.The finite element simulation software FDS(Fire Dynamic Simulator)was used to simulate and calculate the fire in ammunition compartment under different working conditions.Firstly,the principle of explosive caused by heat is determined,and the critical parameters of thermal explosion of the selected projectile are calculated by the formula.Secondly,the layout of the ammunition compartment is verified and determined,and the optimum mesh size of the finite element model of the ammunition compartment is obtained by using the formula.The development process of the fire in the ammunition compartment and the change of its internal temperature field were studied by setting the temperature slice.The measuring points were set up to analyze the influence of the fire on the charge in different positions of the projectile in different space positions.By setting different fire locations,fire heat release rate and whether there is a spray system three typical working conditions to simulate the impact of different fires on the safety of the projectile.The following research results are obtained:(1)The actual fire power variation curves of four typical initial fire development conditions in the ventilated ammunition compartment are obtained,and the temperature field variation at every moment in the ammunition compartment is obtained;(2)Under slow fire condition,the charging temperature of the launching plane projectile is basically the same except above the fire point.The temperature of the projectile on the vertical plane presents the situation that the temperature of the projectile near the fire point is low and high,while the temperature of the projectile far away from the fire point is low and high,and the temperature variation inside each projectile at each time is obtained.(3)The influence of different working conditions on the projectile,the temperature change in the ammunition chamber before and after the spray system is opened,and the temperature change of the projectile charge.The results show that the fire point has a great influence on the projectile near it,and the change of its position can affect the time when the projectile reaches the critical temperature.The fire heat release rate mainly affects the temperature rise of the projectile.The spray system can reduce the overall temperature in the cabin and delay the temperature rise of the projectile.