Free-shape modeling and optimization for cold plates with tree-like channels

Abstract

The use of cold plates is often considered a preferred cooling strategy to quickly remove detained heat from inside the system, which is widely used in engineering applications such as battery thermal management systems (BTMSs). Structural designs are essential to cold plate designs and serve as the foundation for other subsequent designs. This study introduces a free-shape modeling method for the structural design of cold plates with tree-like channels. The geometric characteristics include tree-like features (branching angles, lengths, numbers, and levels), passage patterns, elliptical cross-section sizes and shapes, and channel twists. They can all be freely revised by adjusting the related control parameters. A case of Cold Plates with Tree-like and Straight Channels (CPTSC), which is frequently found in BTMSs, is designed to verify the universality and effectiveness of the proposed free-shape modeling method. After that, the optimization technology based on the NSGA-II evolutionary algorithm is used to minimize the average temperature (overall thermal performance) and root mean square temperature (temperature uniformity) of top and bottom surfaces. The generalized minimum residual (GMRES) method is utilized for the numerical analyzes, and the numerical results indicate that the resulting designs can reduce the average temperature and root mean square temperature by up to 5.91 K (1.75%) and 2.06 K (23.54%), respectively, for Re=1000 and a total power of 600 W. The numerical and experimental results show that the structure of the best compromised solution reduces both thermal indicators by 5.79 K (1.72%) and 1.88 K (21.49%), respectively. This work provides a guideline for the design of tree-like structures that can be used not only in flat-panel cold plates but also in disk-shaped cold plates, heat sink with fins, and heat sink filled with phase change materials.