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 transp...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 Al_(2)O_(3) 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 Al_(2)O_(3) 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 Al_(2)O_(3) and CuO NPs under the same conditions.展开更多
基金the National Natural Science Foundation of China for financial support(No.51890894)Scientific and Technological Innovation Foundation of Shunde Graduate School,USTB(Grant No.BK19AE012).
文摘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 Al_(2)O_(3) 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 Al_(2)O_(3) 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 Al_(2)O_(3) and CuO NPs under the same conditions.
