Computational study of flow boiling heat transfer enhancement in Grooved Wall channels

Abstract

Using specially structured surfaces such as a grooved surface to enhance the flow boiling heat transfer has many advantages; it enhances the ebullition cycle of the nucleate boiling and improves the two-phase flow on the heated wall, significantly boosting the heat transfer coefficient. The grooves allow surface tension forces to play a role during the boiling process under certain conditions, which also assists in the creation and detachment of the bubbles. This study employed a computational study based on a mechanistic flow-boiling model to simulate the flow for the subcooled boiling phenomenon on grooved surfaces. Bubble creation, growth, and departure were computationally studied for various wall structures: smooth wall, V-shaped grooved wall, and U-shaped grooved wall. The results were validated by comparing them to an experimental study in terms of the bubbles' creation and departure parameters. The results reveal a significant improvement in thermal efficiency following U-shaped grooved wall use.