English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

In this paper, the performance of two lattice Boltzmann method formulationsfor yield-stress (i.e. viscoplastic) fluids has been investigated. The firstapproach is based on the popular Papanastasiou regularisation of the fluidrheology in conjunction with explicit modification of the lattice Boltzmannrelaxation rate. The second approach uses a locally-implicit formulation tosimultaneously solve for the fluid stress and the underlying particledistribution functions. After investigating issues related to the latticesymmetry and non-hydrodynamic Burnett stresses, the two models were compared interms of spatial convergence and their behaviour in transient and inertialflows. The choice of lattice and the presence of Burnett stresses was found toinfluence the results of both models, however the latter did not significantlydegrade the velocity field. Using Bingham flows in ducts and synthetic porousmedia, it was found that the implicitly-regularised model was superior incapturing transient and inertial fluid behaviour. This result presentspotential implications for the application of the Papanastasiou-regularisedmodel in such scenarios. In creeping flows the performance of both models wasfound to be both similar and satisfactory.

On the spatial convergence and transient behaviour of lattice Boltzmann methods for modelling fluids with yield stress