Abstract: Heat transfer performance of nanofluid is superior to that of original pure fluid because the suspended nanoparticles remarkably increase the thermal conductivity of the mixture and improve its capability of energy exchange.The evaporation of nanofluid droplet will be widely applied in the field of vehicle,spaceflight,voyage,shipping and electron.The hydrokinetics,theories on heat and mass transfer and material science,and the behavior dynamics of free interface are involved in the evaporation process of nanofluid droplets.In this study,lattice Boltzmann method is applied to simulate the deformation of nanofluid droplet when it evaporates on a heated horizontal surface.A double distribution model is adopted,in which D2Q9 is used to calculate the velocity distribution while D2Q5 is used for calculation of temperature distribution.The results show that the nanofluid droplet experiences pinning and depinning stages.Because of the strong pinning action of nanoparticles,the ring sediment is specially investigated at the end of evaporation,which shows the characteristics of nanofluid as the result of strong pinning action with the Brownian motion and the interaction between the particles considered.The simulation results are in good agreements with the experimental results in literature.

Key words: lattice Boltzmann method, nanofluid, droplet, evaporation

摘要： 采用格子Boltzmann力矩模型模拟了纳米流体液滴在水平加热面上的变形过程,结果表明纳米流体液滴的变形经历了销联、解销阶段,并且由于纳米颗粒的强销联作用,在蒸发的后期可以明显看出环形沉积,这是在考虑布朗运动、粒子间相互作用等作用力后由于纳米颗粒的强销栓作用而表现出的纳米流体的独有性质。模拟结果与文献中的实验结果作了对比,表现出良好的一致性,表明格子Boltzmann方法可以成功模拟纳米流体液滴在水平加热表面蒸发过程中的变形特点。

关键词: 格子Boltzmann方法, 纳米流体, 液滴, 蒸发