Numerical investigation of cooling characteristics for fine mist cooling of high temperature material

Mist cooling is a technology to cool high temperature surfaces using an evaporative latent heat associated with the vaporization of atomized droplets. It has higher cooling capacity than the conventional cooling techniques such as forced convection, as it takes advantage of relatively large values of evaporative latent heat. In this paper, fine mist cooling as a high heat removal technology has been applied to the cooling of a high temperature work material. A threedimensional numerical simulation has been developed in order to investigate the behavior of fine mist particles, flow of gas phase and temperature of work material. Model predictions show that water droplets hardly evaporate in the gas phase of the analytical domain; approximately 45% of fine mist particles flow out of the analytical domain and approximately 55% of fine mist particles collide on the work material. 10%-20% of collided water droplets evaporate on the work material and 80%-90% of collided water droplets stay on the work material under steadystate condition. Collision of fine mist particles on the work material has a high frequency in the central part of the device and the collision frequency of fine mist particles decreases with an increasing distance from the center of the work material. As a result, the surface temperature of the work material is comparatively low in the central part of the work material due to the evaporative latent heat of fine mist particles and becomes higher toward the outside of the work material.