Study on heat transfer enhancement performance of cooling channel with elliptical dimples in a proton exchange membrane fuel cell

Cooling channel (CC) design is an effective measure to improve the internal thermal management of proton exchange membrane fuel cells (PEMFC). In this paper, a new elliptical dimple (EDC) cooling channel structure is proposed. The heat transfer and flow characteristics of EDC, circular dimpled cooling channel (CDC), and smooth cooling channel (SC) are compared by numerical simulation method, and the influence of elliptical dimple structural parameters on their performance is discussed. The serpentine CC with elliptical dimples is further compared with the traditional serpentine CC. The results indicate that the EDC is more effective than the other two types due to the narrow surface of the elliptical dimple, which enhances fluid flow and creates a region at the trailing edge of the vortex that promotes heat exchange. It is worth noting that lengthening the elliptical dimple leads to reduced performance, while elongating it initially improves but eventually decreases performance. This study found that the EDC with an elliptical dimple of 0.1 mm depth and 0.6 mm length outperformed the SC, resulting in a 10.6% improvement. Furthermore, the elliptical dimple serpentine cooling channel was found to enhance heat transfer and reduce pressure loss.