Computational modeling of magnetoconvection: Effects of discretization method, grid refinement and grid stretching

•Buoyancy convection under effect of a strong magnetic field is studied.•Two independent computations are performed.•Convergence is studied.•Converged benchmark-quality solutions are reported.•Flow patterns are depicted and discussed. The problem of natural convection in a laterally heated three-dim...

Full description

Saved in:
Bibliographic Details
Published in:Computers & fluids 2018-10, Vol.175, p.66-82
Main Authors: Gelfgat, A.Yu, Zikanov, O.
Format: Article
Language:English
Subjects:
Convergence
Discretization
Fluid mechanics
Free convection
Grid refinement (mathematics)
Hartmann number
Heat transfer
Kinetic energy
Kinetics
Magnetic fields
Mathematical models
Numerical methods
Rayleigh number
Stretching
Temperature gradients
Two dimensional models
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•Buoyancy convection under effect of a strong magnetic field is studied.•Two independent computations are performed.•Convergence is studied.•Converged benchmark-quality solutions are reported.•Flow patterns are depicted and discussed. The problem of natural convection in a laterally heated three-dimensional cubic cavity under the action of an externally imposed magnetic field is revisited. Flows at the Rayleigh number Ra=106 and the Hartmann number Ha=100, and three different orientations of the magnetic field are considered. The problem is solved using two independent numerical methods based on the second order finite-volume discretization schemes on structured Cartesian grids. Convergence toward grid-independent results is examined versus the grid refinement and near-wall grid stretching. Converged benchmark-quality results are obtained. It is shown that for convection flows with a strong magnetic field a steep, sometimes extremely steep, stretching near some of the boundaries is needed. Three-dimensional patterns and integral properties of the converged flow fields are reported and discussed. It is shown that the strongest magnetic suppression is yielded by the field directed along the imposed temperature gradient. The horizontal magnetic field perpendicular to the imposed temperature gradient stabilizes the main convection roll and leads to a flow with higher kinetic energy and heat transfer rate than in the non-magnetic case. Applicability of the quasi-two-dimensional model to natural convection flows in a box is discussed.
ISSN:0045-7930
1879-0747
DOI:10.1016/j.compfluid.2018.08.020