The purpose of this paper is to test the applicability of a fast boundary element method in the context of geoid computations of the gravity. The fast multipole method is the method of choice due to the its advantageous property of a fast evaluation in the post-processing. Several sets of trianglar meshes for the approximation of the unit sphere and several modifications of the prediscribed dat...

The aim of medical image registration is to bring different images into the best possible spatial correspondence in order to obtain complementary information for clinical applications. When using physically-based techniques for image registration the transformation of images is typically obtained as the solution of partial differential equations of continuum mechanics. Because of the complexity...

A boundary element method is applied for the numerical solution of a boundary value problem for a two-dimensional steady-state bioheat transfer model of the human eye. The human eye is modeled as comprising four distinct homogeneous regions. The boundary condition on the outer surface of the cornea is non-linear due to heat radiation. An iterative approach is used to treat the non-linear heat r...

this paper presents the bending analysis of annular plates by the indirect trefftz boundary approach. the formulation for thin and thick plates is based on the kirchhoff plate theory and the reissner plate theory. the governing equations are therefore a fourth-order boundary value problem and a sixth-order boundary value problem, respectively. the trefftz method employs the complete set of solu...

This paper establishes a foundation of non-conforming boundary elements. We present a discrete weak formulation of hypersingular integral operator equations that uses Crouzeix–Raviart elements for the approximation. The cases of closed and open polyhedral surfaces are dealt with. We prove that, for shape regular elements, this non-conforming boundary element method converges and that, up to log...

A boundary element formulation for the solution of multiple moving boundary problems is presented and tested herein. A heat transfer problem involving heating of solid, melting of solid and vaporisation of liquid is considered. Numerical results show that the boundary element method is more suitable and more accurate than both finite difference and finite element methods for this kind of problems

At present, the main numerical modelling techniques for acoustic and (coupled) vibro-acoustic analysis are based on element based techniques, such as the finite element and boundary element method. Due to the huge computational efforts, the use of these deterministic techniques is practically restricted to lowfrequency applications. For high-frequency modelling, some alternative, probabilistic ...

Green’s functions are important mathematical tools in mechanics and in other parts of physics. For instance, the boundary element method needs to know the Green’s function of the problem to compute its numerical solution. However, Green’s functions are only known in a limited number of cases, often under the form of complex analytical expressions. In this article, a new method is proposed to ca...

We calculate elastic moduli and viscosities for media containing strongly interacting in-plane shear cracks. The cracks are randomly oriented or aligned, with equal length or a logarithmic size distribution. Our results from both a boundary element and a finite-element method suggest that the average moduli are best approximated by a differential, self-consistent model (DEM). Thus crack-tocrack...

This paper deals with a general framework for a posteriori error estimates in boundary element methods which is specified for three examples, namely Symm's integral equation, an integral equation with a hypersingular operator, and a boundary integral equation for a transmission problem. Based on these estimates, an analog of Eriksson and Johnson's adaptive finite element method is proposed for ...