Effects of combination modes of different cavities and ribs on performance in mini-channels - A comprehensive study

Abstract

To raise the efficiencies of the micro/mini-channel heat sink and promote its application in more heat dissipation field. The channel modification technology had been widely explored and studied. In this investigation, several mini-channels with different ribs and cavities are put forward. Besides, their hydraulic characteristics, heat transfer characteristics, overall thermal performance, temperature uniformity and compressive temperature uniformity are investigated by adopting the numerical simulation. The results suggest that the introduction of rib into the mini-channel can enhance heat transfer but also can bring about increasing in the flow resistance. Although the presence of cavity structure can ameliorate the flow performance, the heat transfer performance is unsatisfactory. However, when the rib and cavity structures are adopted together, these mini-channels present better performance than that of applying only one kind of the micro-structure (rib or cavity) and smooth mini-channel. The mini-channel with the combination of the rectangular rib and trapezoidal cavity exhibits the best overall thermal performance around all studied cases, and the maximum overall thermal performance of 1.33 at Reynolds number of 496 is achieved. Furthermore, the mini-channel with the combination of forward triangular rib and forward triangular cavity yields the best temperature uniformity. Which is improved by 62.3% than smooth mini-channel.