Progressive review of heat transfer enhancement technologies in 2010-2020

With the rapidly increasing demand for high-flux heat transfer in engineering applications, e.g. 5G microchips, concentrating photovoltaic cells and next-generation nuclear reactor cores, not only existing microchannel heat transfer enhancement technologies are being significantly improved, but also novel technologies have been being proposed in recent years, which raises the necessity of a timely progressive review. Therefore, the present review focuses on the latest works regarding heat transfer enhancement technologies reported in 2010-2020 and strives to give a comprehensive summary of major advancements. Firstly, the various enhancement technologies are systematically divided into 7 main categories with 19 sub-categories based on the implementation method. Secondly, specific reviews and comments over individual technologies are given with tabular key data and information for clear comparison. Thirdly, the most significant performance indices of heat transfer enhancement (in terms of Nusselt number and heat transfer coefficient), flow resistance (in terms of pressure drop and flow resistance coefficient) and the integrated index of the two for all the technologies reviewed in this work are graphically overviewed and comprehensively analyzed. Finally, the existing drawbacks in current research are presented and suggestions are put forward as the fundamental guidance for future studies.