Experimental study and correlation development for the two-phase frictional pressure drop of flow boiling in copper foam fin microchannels  

作　　者：FU Kai XU XiangHua LIANG XinGang 

机构地区：[1]School of Aerospace Engineering,Tsinghua University,Beijing 100084,China

出　　处：《Science China(Technological Sciences)》2024年第9期2758-2776,共19页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.51876102);the Tsinghua University Initiative Scientific Research Program。

摘　　要：Flow boiling in microchannels with porous walls has received extensive attention in recent years. Compared with the emphasis on heat transfer, there is a lack of research on the effect of the porous wall structures on the pressure drop characteristics. In this study, systematic experiments are performed to measure the pressure drop of water-vapor two-phase flow in five microchannels with copper foam fins, which consist of nine or six channels and fins of copper foam. The porosities of the foam fins range from0.78 to 0.82 and ratios of fin width to channel width range from 0.5 to 2. The channels are approximately 0.5 or 1 mm in width and 1 mm in height. Both adiabatic and flow boiling experiments are conducted with water at mass fluxes ranging from 66 to 407 kg/(m^(2)s). In the adiabatic experiments, the average quality in channels is between 0.017 and 0.846. In the flow boiling experiments, the outlet quality of channels is between 0.040 and 0.863. Slug flow, churn flow, annular flow, and wispy-annular flow are observed in adiabatic experiments. A two-phase frictional pressure drop correlation based on the Lockhart-Martinelli model is developed for copper foam fin microchannels by introducing the effects of the mass flux, porosity, ratio of fin width to channel width, and heating condition step by step. The mean absolute percentage errors of the new correlation are 7.53% for 325data points under adiabatic conditions and 5.51% for 268 data points under flow boiling conditions, respectively. This work provides insight into the correlations of frictional pressure drop in microchannels with porous walls.

关 键 词：TWO-PHASE flow boiling pressure drop CORRELATION MICROCHANNEL copper foam porous wall 

分 类 号：TK124[动力工程及工程热物理—工程热物理] TG146.11[动力工程及工程热物理—热能工程]