Single phase laminar flow and heat transfer characteristics of microgaps with longitudinal vortex generator array

We study the integration of longitudinal vortex generators (LVGs) into microgaps for heat transfer augmentation via three-dimensional steady numerical simulations Firstly, the impacts of geometric parameters, including transverse spacing of LVG pairs, height of microgaps, and number of LVG pairs in the flow direction were considered. Then the heat transfer and flow resistance of LVG enhanced micro-gap were compared with smooth micro-gap. The results show that the flow resistance and heat transfer performance of LVGs enhanced microgaps decrease with increase in transverse spacing of LVGs. Microgaps with larger heights do not demonstrate a significant increase in heat transfer performance, but have much lower pressure drop. The microgap equipped with more LVG pairs has higher pressure drop and heat transfer coefficients. Finally, compared with the smooth microgap, the overall enhancement ratio of all studied LVGs enhanced microgaps increases with Re, and the overall enhancement ratios of specific LVGs enhanced microgap model is larger than one over the full range of Re being studied. The present study is intended to promote the development of new heat transfer enhancement technique in microgaps. (C) 2017 Published by Elsevier Ltd.