Journal
JOURNAL OF COMPUTATIONAL SCIENCE
Volume 51, Issue -, Pages -Publisher
ELSEVIER
DOI: 10.1016/j.jocs.2021.101363
Keywords
Lattice-Boltzmann; OpenLB; Advection-diffusion; Finite-difference
Funding
- UKRI Engineering and Physical Sciences Research Council via EPSRC Grant [EP/R01485X/1]
- German Research Foundation [DFG 436212129]
Ask authors/readers for more resources
The research proposes two 3D models to overcome numerical instability issues in high-Peclet flows, coupling a Lattice-Boltzmann Navier-Stokes solver with an advection-diffusion model or a finite-difference algorithm. Through improving numerical diffusivity and validation tests, it is shown that the coupled finite-difference/Lattice-Boltzmann model provides stable solutions in the case of infinite Pe and Pe(g).
Traditional Lattice-Boltzmann modelling of advection-diffusion flow is affected by numerical instability if the advective term becomes dominant over the diffusive (i.e., high-Peclet flow). To overcome the problem, two 3D one-way coupled models are proposed. In a traditional model, a Lattice-Boltzmann Navier-Stokes solver is coupled to a Lattice-Boltzmann advection-diffusion model. In a novel model, the Lattice-Boltzmann Navier-Stokes solver is coupled to an explicit finite-difference algorithm for advection-diffusion. The finite-difference algorithm also includes a novel approach to mitigate the numerical diffusivity connected with the upwind differentiation scheme. The models are validated using two non-trivial benchmarks, which includes discontinuous initial conditions and the case Pe(g) -> infinity for the first time, where Pe(g) is the grid Peclet number. The evaluation of Pe(g) alongside Pe is discussed. Accuracy, stability and the order of convergence are assessed for a wide range of Peclet numbers. Recommendations are then given as to which model to select depending on the value Pe(g)-in particular, it is shown that the coupled finite-difference/Lattice-Boltzmann provide stable solutions in the case Pe -> infinity, Pe(g) -> infinity.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available