Conjugate Heat Transfer in Two-Phase Flow in Microtube

Abstract

Flow boiling in microchannel is a promising way for removal of high heat flux. This work presents a systematic two- dimensional numerical study of the conjugate effect of heat transfer in two-phase flow in a microtube subjected to constant heat flux. The fluid is assumed to be water which enters in the microtube with a preheated temperature of 373 K. It is intended to obtain the enhancement in heat transfer by taking in account the flow boiling effect. Furthermore, the effect of wall to fluid conductivity ratio (ksf), tube wall thickness to tube inner radius ratio (δsf), and inlet Reynolds number in an unsteady flow boiling of water in a microtube under constant heat flux are studied. The result indicates that the mixing of fluid layer is improved due to presence of vapor bubbles along the length of the microtube that results in improvement in overall heat transfer coefficient. The growth and motion of vapor bubble due to evaporation are observed.