Publications

Title : Convergence results of the fictitious domain method for a mixed formulation of the wave equation with a Neumann boundary condition
Year : 2009
Type : paper in peer-reviewed journal
Authors : É. Bécache, J. Rodríguez, C. Tsogka
Abstract : The problem of modeling acoustic waves scattered by an object with Neumann boundary condition is considered. The boundary condition is taken into account by means of the fictitious domain method, yielding a first order in time mixed variational formulation for the problem. The resulting system is discretized with two families of mixed finite elements that are compatible with mass lumping. We present numerical results illustrating that the Neumann boundary condition on the object is not always correctly taken into account when the first family of mixed finite elements is used. We, therefore, introduce the second family of mixed finite elements for which a theoretical convergence analysis is presented and error estimates are obtained. A numerical study of the convergence is also considered for a particular object geometry which shows that our theoretical error estimates are optimal.
Themes : Transient waves
Reference : Mathematical Modelling and Numerical Analysis - vol. 43 (2) (pp 377--398 ) images/icons/doctype_link.gif