Study On Coupled Heat-transfer Process In A Launching Canister

The life of the propellant in the missile is highly affected by temperature in the process of storage. Canister launcher plays the role of heat preservation for the propellant, but in different environment, the temperature is also very different inside canister launcher,especially in hot and cold weather. In order to increase propellant storage life, the air temperature and ventilation quantity of the temperature regulating system can be adjusted to maintain normal storage temperature of the propellant for different environment. So the study of the coupling of temperature in canister launcher can provide technical reference for the missile storage.Computational fluid dynamics software FLUENT was used to simulate the process of coupled heat transfer including heat convection between outside air and canister launcher,heat conduction in each layer, heat radiation and convection between inner wall of the canister-inside air- missile surface and heat conduction in missile body. Firstly, this article analyzed the effect of single boundary for the temperature inside canister. Then, in order to keep the normal missile storage temperature in different environment, this article optimized it from the air temperature, constant temperature device, ventilation quantity, and adapter materials.Based on optimized result, temperature variation was simulated when the canister launcher was moved to different environment so as to determine the time when the temperature regulating system started working. The effects of ventilation quantity and adapter for inside temperature variation ratio were also studied when the temperature regulating system worked.By simulation calculation,it finds that the change of temperature inside canister is less than 1 ? if the boundary temperature is the same when the outer boundary is only constant temperature boundary, convection boundary or radiation boundary. In summer, radiation temperature is much higher than the air temperature. Temperature of every part is increased,when convection and solar radiation is considered at the same time. When the air temperature is 40 ? and the radiation temperature is 70 ?, canister surface temperature will be above 46 ? . So the temperature effect coming from solar radiation cannot be ignored. During missiles storage, air temperature makes a big influence for bulk temperature of three segment propellants. Ventilation quantity mainly affects the temperature of the head propellant.Constant temperature device can limit the maximum or minimum temperature of the bottom propellant. Adapter plays the role of stream guidance which makes surface temperature more uniform. The heat conductivity coefficient of adapter also has effects on the temperature of missile.The temperature decreasing rate in winter is faster than the increasing rate in summer, if indoor temperature is the same after the canister launcher is moved to outdoors. After the ventilation works, the temperature changes fastest within seconds. After 6 hours, all parts of the temperature doesn't change anymore. Adapter plays the role of stream guidance, but it also limits the air flowing. So the temperature changes slowly in the early stage of the ventilation. The increase of ventilation quantity could speed up the heat transfer, but it also affects the average temperature of the missile if the ventilation quantity is too large.