Fluid with internal wettability

Abstract

Our aim is to improve the macroscopic description of wetting. We adopt the framework of the “fluids with internal capillarity” theory, for which the fluid–fluid interfaces are defined as zones (i.e. interfaces with a thickness), where lies a strong density variation. The continuum mechanics equations, considering the fluid–fluid interfacial zone, allow the concept of interfacial tension and Laplace's law to be rediscovered by limit processes. Following this modeling, we propose to characterize the transition zone between a fluid and a solid. We build a fluid model, with a constitutive law valid in the vicinity of a solid wall. Moreover, we estimate internal and external actions of this wall on the considered fluid by using a simplified molecular theory. We write out the system of equations and present some preliminary results for the peculiar case of a static drop.