Thermophoretically driven capillary transport of nanofluid in a microchannel

Abstract

We investigate the interplay of thermophoretic force and interfacial tension on the capillary filling dynamics of a Newtonian nanofluid in a microchannel. In our model, we also consider an intricate thermofluidic coupling by taking the temperature dependence of viscosity aptly into account. This, in turn, determines the evolution of the viscous resistive force as the capillary front progresses, and presents an involved inter-connection between the driving thermophoretic force and the viscous resistive force. The two distinct regimes of particle transport in a fluid medium, delineated by particle size, are expounded to peruse the impact of imposed thermal gradients and particle size on particle retaining propensity of the nanofluid. Additionally, we witness a significant reduction in particle bearing proclivity of the nanofluid with enhancement in a thermal gradient. The results demonstrate the efficacy of the thermophoretic actuation towards the filling of narrow capillaries under the influence of a thermal gradient.