Effects of flow characteristics on the heat transfer mechanism in Taylor flow

Abstract

The capability of Taylor slugs to enhance heat transfer rate compared to that obtained from single-phase flow is well-documented. This study numerically investigated the hydrodynamics characteristics and heat transfer mechanism in liquid-liquid Taylor flow. A novel analysis method was introduced by comparing fluid flow and heat transfer parameters distributed at the axial and radial planes of the channel. In order to investigate transport phenomena, the unit cell length and frequency of slug generation over a wide range of phase superficial velocity ratio were examined. The simulations showed that the viscosity difference between the phases is a critical parameter of the slug frequency; a higher amount increases the frequency much greater. Conversely, a lower viscosity difference between the phases allows water slugs to expand axially more. The higher temperature gradient and a stronger recirculation in the shorter liquid plug region enhance the heat transfer rate leading to the highest cooling performance over the channel wall within a unit cell. The results also showed the significant importance of establishing shorter slugs, which improves the cooling performance in the slugs and enhances the heat transfer rate in the liquid slug region due to the greater radial flow mixing. The developed numerical model was verified by the results found in the literature showing good agreement.