Bubble injection for heat transfer enhancement: From physics to applications

This article presents a comprehensive review of recent advancements in bubble-induced heat transfer enhancement, with a primary focus on understanding the fundamental underlying physics. Accordingly, this review first highlights recent novel concepts and techniques developed to enhance heat transfer through bubble injection, followed by explaining the essential physical aspects of this development. It attempts to clarify the impact of bubble injection on heat transfer by examining key mechanisms in two-phase bubbly flow. The factors that influence heat transfer and fluid flow, including mechanisms of bubble ascent, bubble breakage, and coalescence, as well as the impact of bubble size and shape, are examined. Furthermore, the review explores the use of bubble injection in different types of heat exchangers in addition to other applications, including solar collectors, hydrogen production, internal combustion engines, and energy storage systems. Furthermore, the article identifies current research gaps and existing challenges and suggests potential directions for future research in bubble-induced heat transfer enhancement.