Study on the effect of angle of elliptical dimple on the flow and heat transfer performance of pillow-plate heat exchangers

With an excellent pressure resistance, compactness and excellent flow heat transfer characteristics, pillow-plate heat exchangers (PPHEs) have a good development prospect in the field of heat exchangers. In this paper, the PPHE with different dimple angles is numerically simulated, and the influence of dimple angle on the flow heat transfer is revealed by analysing the relevant contours and data. The conclusions are as follows: when the dimple angle is 90°, the magnitude of heat transfer enhancement is the largest, with an enhancement of 5.14%~8.06%. When the angle of the dimple is 0°, the heat transfer enhancement is the smallest, and the enhancement is 3.81%~5.97%. The dimples improve the heat transfer performance in the recirculation zone by disturbing and guiding the fluid.