Thin film evaporation: New insights with nanofluid inclusion and component of the electrostatic interactions

Abstract

To assess the implications of the evaporating meniscus in microfluidic channels, extensive explorations have been going on to simulate the fluid flow behavior and the transport phenomena. The present work explores new insights into the evaporating meniscus after including the nanofluid (alumina + water) as a working fluid. This work first emphasizes encapsulation of the different components of the disjoining pressure that arises due to the interactions between the nanoparticles (Al2O3) and the nanoconfined polar liquid including the wall slip effect and later delineates the physics of the results obtained. The investigation will provide crucial insights through a comprehensive enumerated theoretical model comprised of the Young–Laplace equation, kinetic-theory-based mass transport, and the lubrication theory in the purview of evaporating nanofluid meniscus. This study also highlights the selection of the thin film thickness and the dispersion constant at the inception of the evaporation, as they cannot be chosen arbitrarily. A nondimensional approach is opted to explicate different facets of the thin film evaporation region. The results revealed that the nanofluid inclusion increases the overall heat transfer and the thickness of the evaporating meniscus. However, nullifying the combined effect of the electrostatic component of the disjoining pressure and wall slip will exaggerate the net increase in the heat transfer process and understate the increase in the thickness of the evaporating thin film, primarily if a polar liquid is used to unveil the characteristics of the evaporating nanofluid meniscus.