Drag on a plate perpendicular to the flow of an elasto-viscoplastic fluid

Abstract

AbstractThe flow with no inertia of an elasto-viscoplastic fluid around a plate perpendicular to the flow direction was considered. Firstly, experiments were performed with a model yield stress fluid, an aqueous Carbopol gel. The viscoelastic behavior of the fluid is identified by steady and transient rheological measurements. The drag force on the plate has been measured as a function of the plate velocity in steady state and in relaxation after stopping the movement. The role of the initial stress state in the fluid was highlighted. Secondly, numerical simulations were carried out using the finite element method with Lagrangian integration points. As a first approach, the elasto-viscoplastic behaviour of the gel has been simplified by a constitutive equation based on the Maxwell and Herschel-Bulkley models. The solid–liquid transition is defined by the von Mises criterion. The comparison between experimental and numerical data are quite satisfactory.