Numerical Simulation Of Cooling Water Process Of Plasma Spraying Casting

Recently, plasma has been applied widely in production and research. There are a lot of methods to produce plasma, but the method that used thermocompression to product plasma is used most widely. Generally plasma is produced by the thermocompression from the gun-body. The thermocompression effect of the plasma gun is mainly completed by the inside water-cooling system, and the ideal water-cooling system should be able to take away the heat quantity produced by the plasma beam duct as soon as possible. Water-cooling influences straightly the figure of the plasma jet, and finally effects spray efficiency. If the nozzle isn't achieved cooling timely, the nozzle will burn out, and will affect the life of the plasma gun. Therefore, it is important to research on the cooling water flow-field of the plasma gun. Whit the high development of computer and numerical simulation software, it is possible to simulate water-cooling of plasma gun.This paper built the mathematic model of the cooling water flow and heat transfer of the plasma spraying gun and calculated on it through the FLUENT software. Temperature field and velocity field of the nozzle has been obtained and the nozzle's energy distribution has been shown. Asynchronous anode macula is simulated numerically, and influence of nozzle's energy distribution is analyzed. The parameter of water-cooling velocity(1m/s～7m/s), water direction(positive and negative), water pipe position(z=13mm～z=19), water pipe diameter(6mm～10mm)is simulated numerically and temperature field of the nozzle has been obtained. Influence of velocity, direction, position and diameter to cooling effect is analyzed.At the same time, this paper simulates cooling of the tungsten electrode, and energy distribution of the tungsten electrode is achieved. This paper simulates cooling of tungsten electrode only used argon, and the influence of cooling effect is analyzed. It also simulates cooling of tungsten electrode only used water (including positive and negative), and the influence of cooling effect is analyzed. At last it simulates cooling of tungsten electrode used argon and water (including positive and negative), and the influence of cooling effect is analyzed. The conclusions show that numerical simulation results can reflect preferably the cooling water flow and heat transfer of the plasma spraying gun by FLUENT software, which is provides theoretic help to the plasma spraying gun design.