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Highly parallelisable simulations of time-dependent viscoplastic fluid flow simulations with structured adaptive mesh refinement


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Authors

Nikiforakis, Nikolaos  ORCID logo  https://orcid.org/0000-0002-6694-2362
Almgren, Ann 

Abstract

We present the extension of an efficient and highly parallelisable framework for incompressible fluid flow simulations to viscoplastic fluids. The system is governed by incompressible conservation of mass, the Cauchy momentum equation and a generalised Newtonian constitutive law. In order to simulate a wide range of viscoplastic fluids, we employ the Herschel-Bulkley model for yield-stress fluids with nonlinear stress-strain dependency above the yield limit. We utilise Papanastasiou regularisation in our algorithm to deal with the singularity in apparent viscosity. The resulting system of partial differential equations is solved using the IAMR code (Incompressible Adaptive Mesh Refinement), which uses second-order Godunov methodology for the advective terms and semi-implicit diffusion in the context of an approximate projection method to solve on adaptively refined meshes. By augmenting the IAMR code with the ability to simulate regularised Herschel-Bulkley fluids, we obtain efficient numerical software for time-dependent viscoplastic flow in three dimensions, which can be used to investigate systems not considered previously due to computational expense. We validate results from simulations using this new capability against previously published data for Bingham plastics and power-law fluids in the two-dimensional lid-driven cavity. In doing so, we expand the range of Bingham and Reynolds numbers which have been considered in the benchmark tests. Moreover, extensions to time-dependent flow of Herschel-Bulkley fluids and three spatial dimensions offer new insights into the flow of viscoplastic fluids in this test case, and we provide missing benchmark results for these extensions.

Description

Keywords

physics.flu-dyn, physics.flu-dyn, physics.comp-ph

Journal Title

Physics of Fluids

Conference Name

Journal ISSN

1070-6631
1089-7666

Volume Title

30

Publisher

American Institute of Physics
Sponsorship
EPSRC (1645917)
Engineering and Physical Sciences Research Council (EP/L015552/1)
Funding and technical support from BP through the BP International Centre for Advanced Materials (BP-ICAM) which made this research possible.