Lattice Boltzmann Simulation of Nanoparticle Transport and Attachment in a Microchannel Heat Sink

• Published in: Fluid dynamics & materials processing 2021, Vol.17 (2), p.301-317
• Main Authors: Tian, Xiaokang, Yue, Kai, You, Yu, Niu, Yongjian, Zhang, Xinxin
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Attachment; Computational fluid dynamics; Copper; Copper oxides; Diameters; Flow distribution; Heat; Heat sinks; Heat transfer; Microchannels; Nanofluids; Nanoparticles; Polydimethylsiloxane; Silicon dioxide; Temperature distribution; Two phase flow; Wall temperature
• ISSN: 1555-2578; 1555-256X; 1555-2578
• DOI: 10.32604/fdmp.2021.013521

The heat transfer performances of a microchannel heat sink in the presence of a nanofluid can be affected by the attachment of nanoparticle (NP) on the microchannel wall. In this study, the mechanisms underlying NP transport and attachment are comprehensively analyzed by means of a coupled double-distribution-function lattice Boltzmann model combined with lattice-gas automata. Using this approach, the temperature distribution and the two-phase flow pattern are obtained for different values of the influential parameters. The results indicate that the number of attached NPs decrease exponentially as their diameter and the fluid velocity grow. An increase in the wall temperature leads to an increase of the attached NPs, e.g., the Al2O3 NPs attached on the CuO microchannel wall increases by 105.8% in the range between 293 K and 343 K. There are more attached NPs in microchannels with an irregular structure. The tendency of SiO2 NP to attach to the PDMS (polydimethylsiloxane), Fe and Cu walls is less significant than that for Al2O3 and CuO NP; Moreover, NPs detach from the PDMS microchannel wall more easily than from the Cu and Fe microchannel walls. The SiO2 attachment layer has the greatest influence on the heat transfer performance although its thickness is thinner than that for Al2O3 and CuO NPs under the same conditions.