Numerical study of unsteady pipe flow of an elastoviscoplastic fluid

Overview & Synopsis

In this paper we investigate, numerically, unsteady Poiseuille flow of an elastoviscoplastic fluid. The material is described by the rheological model by Putz and Burghelea [1]. The model can describe an elastic solid regime for low stresses, a solid-fluid phase of stresses in the vicinity of the yield stress and a fully fluid regime for large stresses. We impose a time dependent pressure ramp with the form of a triangular function to drive the flow. We compare average velocity across the pipe as a function of pressure drop for different slip laws. We find that the solid-fluid transition is correlated to the slip-law used in the computations but the boundary conditions do not affect neither the deformation-rates nor stress at the bulk and the wall.