LAUSR

Abstract Emulsions are mixtures of two materials that do not normally mix together and are widely used in many industrial fields. It is thus important to determine the flow and heat transfer characteristics of emulsions. The present study considered the heat transfer characteristics of a silicone-oil-in-water emulsion at room temperature according to the flow characteristics of the emulsion. The silicone-oil-in-water emulsion was prepared varying the volume fraction of the dispersed oil, amount of surfactant and kinematic viscosity of the oil, and the heat transfer coefficient of the emulsion flowing in a horizontal tube was measured. It was found that the heat transfer coefficient of the emulsion can be estimated as that of a single-phase fluid in the case of low viscosity of the dispersed oil. Meanwhile, the heat transfer was enhanced in the case of high viscosity of the dispersed oil. Moreover, approximation equations for the Nusselt number for laminar and turbulent flow conditions were derived from the experimental results.