Hydrodynamic and thermal analysis of water slugs in super-hydrophobic T-Junction microchannel

Abstract

Due to the unrealized potential of microfluidic devices and the advancement of computational approaches to examine the design and flow behaviour of these devices, microfluidics has gotten a lot of attention in recent years. The goal of this research was to look at how air-water bubbles passing through a microchannel with a T-junction. To produce different degrees of wettability, the contact angle was changed. The importance of slug flow in micro-channels was highlighted in this study since it was critical for many microfluidic device applications. Micro reactors, microchannel heat sinks, and other similar devices are examples. To explore the production of slugs, a multiphase model was used to follow the air-water interface. First, it was performed a rigorous mesh independence analysis to determine the best ideal mesh for present research without sacrificing accuracy while conserving computational resources. As a result, it was decided on a mesh size of 0.1mm for present research. The 8850 W/m² continuous heat flux utilized on the walls caused the temperature of the wall to vary along its length. The heat transfer enhancement was measured  to cool the wall and increased Nu number due to slug flow. In two-phase settings, slug flow was compared to single phase flow to control the temperature of heated wall and Nusselt number augmentation.  Comparison of single-phase flows, slug flow induced a greater fall in wall temperature and an increase in Nusselt number.