Alqaed Saeed, Mustafa Jawed, Almehmadi Fahad Awjah, Alharthi Mathkar A, Sharifpur Mohsen, Cheraghian Goshtasp
Mechanical Engineering Department, College of Engineering, Najran University, P.O. Box 1988, Najran 61441, Saudi Arabia.
Department of Applied Mechanical Engineering, College of Applied Engineering, Muzahimiyah Branch, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia.
Nanomaterials (Basel). 2022 Oct 30;12(21):3836. doi: 10.3390/nano12213836.
In this paper, two novel micro heat sinks (MHSs) were designed and subjected to thermal analysis using a numerical method. The fluid used was Boehmite alumina-water nanofluid (NFs) with high volume fractions (VOFs). Studies were conducted to determine the influence of a variety of nanoparticle (NP) shapes, such as platelet brick, blade, cylinder, and Os. The heatsink (HS) was made of copper, and the NFs entered it through the middle and exited via four outlets at the side of the HS. The finite element method was used to simulate the NFs flow and heat transfer in the HSs. For this purpose, Multi Physics COMSOL software was used. The maximum and middle values of HS temperature (T-MAX and T-Mid), thermal resistance (TH-R), heat transfer coefficient (h), FOM, etc., were studied for different NP shapes, and with Reynolds numbers (Re) of 300, 1000, and 1700, and VOFs of 0, 3, and 6%. One of the important outcomes of this work was the better thermal efficiency of the HS with rectangular fins. Moreover, it was discovered that a rise in Re increased the heat transfer. In general, adding NPs with high VOFs to MHSs is not appropriate in terms of heat. The Os shape was the best NP shape, and the platelet shape was the worst NP shape for high NPVOF. When NPs were added to an MHS, the temperature of the MHS dropped by an average of 2.8 or 2.19 K, depending on the form of the pin-fins contained inside the MHS (circular or square). The addition of NPs in the MHS with circular and square pin-fins enhanced the pressure drop by 13.5% and 13.3%, respectively, when the Re = 1700.
本文设计了两种新型微热沉（MHS），并采用数值方法对其进行了热分析。所使用的流体是具有高体积分数（VOF）的勃姆石氧化铝 - 水纳米流体（NFs）。开展了研究以确定各种纳米颗粒（NP）形状的影响，如片状砖、叶片状、圆柱状和Os形状。热沉（HS）由铜制成，纳米流体从中间进入热沉，并通过热沉侧面的四个出口流出。采用有限元方法模拟纳米流体在热沉中的流动和传热。为此，使用了多物理场COMSOL软件。针对不同的NP形状，以及雷诺数（Re）为300、1000和1700，体积分数（VOF）为0%、3%和6%的情况，研究了热沉温度的最大值和中间值（T - MAX和T - Mid）、热阻（TH - R）、传热系数（h）、品质因数（FOM）等。这项工作的一个重要成果是带有矩形翅片的热沉具有更好的热效率。此外，发现雷诺数的增加会提高传热。总体而言，就热量而言，向微热沉中添加高体积分数的纳米颗粒并不合适。对于高纳米颗粒体积分数，Os形状是最佳的NP形状，而片状形状是最差的NP形状。当向微热沉中添加纳米颗粒时，根据微热沉内部针翅的形式（圆形或方形），微热沉的温度平均下降2.8K或2.19K。当Re = 1700时，在带有圆形和方形针翅的微热沉中添加纳米颗粒分别使压降增加了13.5%和13.3%。
