Heat Transfer from a Flat Plate in Two-Component Mist Flow

Abstract

An experimental study concerning the characteristics of heat transfer from a dry isothermal flat plate in two-component (water-air) mist flow has been performed for lower water-air mass flow ratios up to 2.3 percent. Heat transfer coefficients in mist flow increase several times corresponding to single phase coefficients with increasing mass flow ratio and free stream velocity, and with decreasing wall temperature. The measurements of droplet velocity employing laser Doppler anemometry indicate the similarity of velocity distributions in boundary layer of mist flow, which approximately fit the laminar single phase one. It is confirmed that an augmentation of heat transfer is attributable to a latent heat due to evaporation of water droplets within the boundary layer, and that, at a constant Reynolds number and wall temperature, the enhanced rates of heat transfer coefficients are linearly correlated to water mass flow rates for unit cross-sectional area.