Numerical Investigation on the Heat Transfer Characteristics of Liquid-Liquid Plug-Train in Microchannels

Publication date: Available online 9 July 2019Source: Chemical Engineering and Processing - Process IntensificationAuthor(s): Bin Xu, Teck Neng Wong, Desheng Zhang, Xi Shen, Rongjun XuAbstractLiquid-liquid plug-train is of great importance due to its wide applications in the heat transfer enhancement and the richness of underlying physics. This paper presented a theoretical and numerical study of the liquid-liquid plug-train in a microchannel. Based on the analytical model of flow field, the heat transfer process in liquid-liquid plug-train was investigated. The constant surface temperature boundary condition was considered. Nusselt number (Nu) and heat transfer index (η) were employed to evaluate the heat transfer characteristics of liquid-liquid plug-train in the microchannel. Three stages of the heat transfer process in liquid-liquid plug-train were identified: (i) development of thermal boundary layer (TBL); (ii) advection of heated/fresh fluid in the liquid-liquid plug train; and (iii) thermally fully developed flow. The effects of the thermal conductivity ratio and the plug length ratio were investigated. A low plug length ratio was found to be effective in heat transfer enhancement in the microchannel.Graphical abstractThis paper presents a theoretical and numerical study of the liquid-liquid plug-train in a microchannel. Based on the analytical model of flow field, the heat transfer process in liquid-liquid plug-train is investigated.

Source: Chemical Engineering and Processing: Process Intensification - July 10, 2019 Category: Chemistry Source Type: research