Numerical simulation of plastic fluids

A finite element numerical procedure is outlined for the solution of flow problems involving fluids with a yield stress. Such materials, termed plastic or viscoplastic fluids, complicate the usual numerical procedures through the introduction of a material nonlinearity. In the present work a specific form for the viscoplastic fluids, complicate the usual numerical procedures through the introduction of a material nonlinearity. In the present work a specific form for the viscoplastic constitutive relation is described that is amenable to numerical solution. A hypermatrix technique is outlined for incorporating the deformation dependent fluid viscosity into the finite element formulation. Two example problems are presented that illustrate the numerical method and the behavior of viscoplastic fluids in complex flows.