HEAT TRANSFER OF LAMINAR MIST FLOW IN CONCENTRIC ANNULI

Abstract

Heat transfer of single-phase flow or mist flow in confined spaces has important application in industrial heat exchangers and nuclear reactors. Extensive research has been conducted for single-phase flow in concentric tubes and eccentric annuli, and an excellent review can be found. However, very few analyses have been devoted to the heat transfer of mist flow in confined spaces due to the complexities of the geometries and phenomena. Numerical results are presented for convective heat transfer of a laminar mist flow in the thermal entrance region of a concentric annulus with a heated core and an insulated outer wall. Both constant temperature and constant heat flux on the inner wall are considered. The saturated droplets in the mist flow are considered as equivalent heat sinks distributed in the superheat vapor velocity, droplet number density, and the local Nusselt number in the streamwise direction until the single-phase fully developed condition is reached. The effects of different governing parameters on heat transfer characteristics are studied.