Modeling of Bubble Merging With Localized Adaptive Mesh Refinement in Customized Ansys-Fluent

Abstract In boiling heat transfer, understanding the behavior of bubble dynamics is essential for improving thermal systems. To enhance heat dissipation with boiling flows, it is important to study boiling phenomena from a fundamental perspective as a means of identifying the relation between the fluid and heat transfer behavior near the interface during bubble growth. This involves analyzing the merging dynamics of bubbles on a heated surface. A key aspect of this is calculating the heat transfer coefficient and influence region, which significantly influences bubble effectiveness to dissipate heat. This study aims to analyze and compare the impact of bubble growth, merging, and departing from a heated surface. A model for 3D multiphase boiling flows using the volume of fluid interface tracking method in Ansys-Fluent is developed in the current study. The simulation focuses on the heat transfer and fluid transport mechanisms during bubble merging. The developed approach is able to observe 3D bubble growth and merging on a heated surface under superheated conditions and is able to visualize and quantify the heat transfer mechanisms near the interface. An average heat transfer coefficient of 12,120 W/m^2 K near bubble departure was observed for the three bubble merger. The findings suggest that the simulation provides an accurate representation of boiling heat transfer and bubble dynamics in three nucleate bubble merging cases. This analysis provides insight into the modeling of boiling heat transfer, emphasizing the importance of accurate modeling of the thermal conditions of the bubble.