These slides were presented at the NAFEMS World Congress 2025, held in Salzburg, Austria from May 19–22, 2025.

Abstract

Recent advancements in triply periodic minimal surfaces (TPMS) have prompted a surge in their application as innovative solutions for efficient heat removal in compact systems. TPMS-based heat exchangers exhibit significant promise for cooling applications due to their high surface area, tunable porosity, and optimized fluid flow characteristics. However, there remains a critical gap in the literature concerning optimizing TPMS design variables to enhance thermal performance and manage pressure, particularly in the context of air-cooled heat exchangers. The present study investigates the thermal and fluid dynamic performance of an air-cooled heat exchanger employing a sheet Diamond TPMS structure. A conjugate heat transfer analysis was conducted using computational fluid dynamics (CFD) via ANSYS Fluent to evaluate the heat transfer and fluid flow characteristics across various configurations. A simplified model was developed in nTop, focusing on a designated design space of 30 mm x 30 mm x 30 mm to facilitate streamlined evaluation. The Design of Experiments (DoE) methodology was employed to explore key design variables systematically. Critical factors under investigation included TPMS unit cell size, wall thickness, and material selection (Aluminum and Copper). The impact of these variables on essential performance metrics'”such as heat transfer rate, cold air flow rate, and hot liquid pressure drop'”was analyzed to identify optimal configurations that maximize thermal efficiency while minimizing pressure losses. The findings reveal that increasing the unit cell sizes and decreasing wall thickness'”thereby enhancing porosity'”significantly improve thermal performance, including heat transfer rates and fluid flow characteristics, while effectively reducing pressure drop. Conversely, the choice of material (Aluminum versus Copper) exhibited a relatively minor influence on heat transfer outcomes, indicating that geometric configuration and porosity are more predominant factors in this application. This study establishes the feasibility of incorporating TPMS structures into heat exchanger designs and offers a systematic approach for identifying optimal configurations by integrating DoE and CFD analysis. By elucidating the most influential design parameters, this research advances effective and efficient heat exchangers, thereby facilitating improved cooling performance in compact devices within various industrial applications.