Parametric charge-conservative mixed finite element method for 3D incompressible inductionless MHD equations on curved domains
Xue Jiang, Lei Li, Lingxiao Li
TL;DR
This work tackles the discretization of the stationary incompressible inductionless MHD equations on curved 3D domains with a focus on charge conservation. It develops a parametric mixed finite element method that combines isoparametric Taylor-Hood elements with grad-div stabilization for $(\boldsymbol u,p)$ and parametric Brezzi-Douglas-Marini elements for the current density, using the Piola transform to enforce $\operatorname{div}\boldsymbol J=0$ exactly on the curved mesh. A rigorous a priori error analysis accounts for geometric approximation via a hold-all domain and proves optimal convergence in the energy norm and in the $L^2$-norm for the velocity, supported by a Stokes projection argument. Numerical experiments on curved meshes verify the theoretical rates and demonstrate discrete charge conservation, highlighting the method’s accuracy and robustness on curved geometries.
Abstract
This paper develops a charge-conservative mixed finite element method with optimal convergence rates for the stationary incompressible inductionless MHD equations on three-dimensional curved domains. The discretization employs the isoparametric Taylor-Hood elements with grad-div stabilization for the velocity-pressure pair, and parametric Brezzi-Douglas-Marini elements for the current density. Utilizing the Piola's transformation, the discrete current density is exactly divergence-free. By employing suitable extensions and projections, optimal a priori error estimates are derived in both the energy norm and the $L^2$-norm. Numerical experiments are presented to confirm the theoretical results.
