Computing weakly singular and near-singular integrals in high-order boundary elements

11/25/2021
by   Hadrien Montanelli, et al.
0

We present algorithms for computing weakly singular and near-singular integrals arising when solving the 3D Helmholtz equation with high-order boundary elements. These are based on the computation of the preimage of the singularity on the reference element using Newton's method, singularity subtraction with high-order Taylor-like asymptotic expansions, the continuation approach, and transplanted Gauss quadrature. We demonstrate the accuracy of our method with several numerical experiments, including the scattering by two nearby half-spheres.

READ FULL TEXT
research
05/05/2023

High-order BDF convolution quadrature for subdiffusion models with a singular source term

Anomalous diffusion is often modelled in terms of the subdiffusion equat...
research
08/30/2019

Solution of Stokes flow in complex nonsmooth 2D geometries via a linear-scaling high-order adaptive integral equation scheme

We present a fast, high-order accurate and adaptive boundary integral sc...
research
08/18/2021

Hybrid high-order method for singularly perturbed fourth-order problems on curved domains

We propose a novel hybrid high-order method (HHO) to approximate singula...
research
09/16/2019

Efficient high-order singular quadrature schemes in magnetic fusion

Several problems in magnetically confined fusion, such as the computatio...
research
08/24/2020

Computing singular elements modulo squares

The group of singular elements was first introduced by Helmut Hasse and ...
research
11/26/2020

Accurate Spectral Collocation Computation of High Order Eigenvalues for Singular Schrödinger Equations

We are concerned with the study of some classical spectral collocation m...
research
10/12/2020

Efficient high-order accurate Fresnel diffraction via areal quadrature and the nonuniform FFT

We present a fast algorithm for computing the diffracted field from arbi...

Please sign up or login with your details

Forgot password? Click here to reset