Zixing Wang, Hao Ding, Le Lei, Nan Li, Wen-Quan Tao
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引用次数: 0
Abstract
Air handling unit (AHU) is the heat exchanger used for data center cooling. This article developed a detailed dimple/protrusion enhanced AHU modeling process and studied the flow and thermal performance of AHU in the Reynold number range from 5 × 103 to 3.53 × 104. Elliptic cylindrical dimples (ECD) and spherical crown dimples (SCD) are applied to enhance heat transfer. The entire channel (EC) and typical unit (TU) simulation domains are compared. The EC simulation domain is more reliable as the TU causes the Nu and f prediction relative deviations as large as 20.53% and 24.03%, respectively. The flow patterns in the channels are analyzed. The results show that the bigger SCD depth and smaller ECD depth make the mainstream bends closer to the “S” shape and the v velocity near the dimple/protrusion wall larger. Also, the second flow vortex distribution pattern becomes more complicated, and the velocity gradient near the wall is increased. These flow patterns enhance heat transfer. The dimpled surface has smaller local convective heat transfer coefficient compared with the protrusion surface in the same channel. With the decrease of ECD depth and the increase of SCD depth, the area-average convective heat transfer coefficient is increased.
期刊介绍:
International Communications in Heat and Mass Transfer serves as a world forum for the rapid dissemination of new ideas, new measurement techniques, preliminary findings of ongoing investigations, discussions, and criticisms in the field of heat and mass transfer. Two types of manuscript will be considered for publication: communications (short reports of new work or discussions of work which has already been published) and summaries (abstracts of reports, theses or manuscripts which are too long for publication in full). Together with its companion publication, International Journal of Heat and Mass Transfer, with which it shares the same Board of Editors, this journal is read by research workers and engineers throughout the world.