Cut finite element method for divergence-free approximation of incompressible flow: A Lagrange multiplier approach
2024 (English)In: SIAM Journal on Numerical Analysis, ISSN 0036-1429, E-ISSN 1095-7170, Vol. 62, no 2, p. 893-918Article in journal (Refereed) Published
Abstract [en]
In this note, we design a cut finite element method for a low order divergence-free element applied to a boundary value problem subject to Stokes' equations. For the imposition of Dirichlet boundary conditions, we consider either Nitsche's method or a stabilized Lagrange multiplier method. In both cases, the normal component of the velocity is constrained using a multiplier, different from the standard pressure approximation. The divergence of the approximate velocities is pointwise zero over the whole mesh domain, and we derive optimal error estimates for the velocity and pressures, where the error constant is independent of how the physical domain intersects the computational mesh, and of the regularity of the pressure multiplier imposing the divergence-free condition.
Place, publisher, year, edition, pages
Society for Industrial and Applied Mathematics, 2024. Vol. 62, no 2, p. 893-918
Keywords [en]
compatible finite elements, CutFEM, fictitious domain, incompressibility, Lagrange multipliers, Stokes' equations, Boundary conditions, Boundary value problems, Finite element method, Incompressible flow, Mesh generation, Boundary-value problem, Compatible finite element, Divergence free, Divergence-free elements, Fictitious domains, Lagrange multiplier approach, Low order, Stokes equations
National Category
Mathematics
Identifiers
URN: urn:nbn:se:hj:diva-64136DOI: 10.1137/22M1542933ISI: 001197029500001Scopus ID: 2-s2.0-85191583237Local ID: ;intsam;949929OAI: oai:DiVA.org:hj-64136DiVA, id: diva2:1856480
Funder
Swedish Research Council, 2017-03911, 2018-05262, 2021-04925, 2022-039082024-05-072024-05-072025-01-31Bibliographically approved