A fast singular boundary method for 3D Helmholtz equation

2019 ◽  
Vol 77 (2) ◽  
pp. 525-535 ◽  
Author(s):  
Weiwei Li
Keyword(s):  
Helmholtz Equation ◽  
Singular Boundary ◽  
Boundary Method ◽  
Singular Boundary Method

Singular Boundary Method for Various Exterior Wave Applications

2015 ◽  
Vol 12 (02) ◽  
pp. 1550011 ◽  
Author(s):  
Zhuo-Jia Fu ◽  
Wen Chen ◽  
Ji Lin ◽  
Alexander H.-D. Cheng
Keyword(s):  
Fundamental Solution ◽  
Helmholtz Equation ◽  
Laplace Equation ◽  
International Workshop ◽  
Fundamental Solutions ◽  
Singular Boundary ◽  
Intensity Factors ◽  
Trefftz Method ◽  
Boundary Method ◽  
Singular Boundary Method

This paper presents an improved singular boundary method (ISBM) to various exterior wave applications. The SBM is mathematically simple, easy-to-program, meshless and introduces the concept of source intensity factors to eliminate the singularity of the fundamental solutions. In this study, we first derive the source intensity factors of the exterior Helmholtz equation by means of the source intensity factors of the exterior Laplace equation due to the same order of the singularities on their fundamental solutions. The source intensity factors of the exterior Laplace equation can be determined using the reference technique [Chen, W. and Gu, Y. [2011] "Recent advances on singular boundary method," Joint international workshop on Trefftz method VI and method of fundamental solution II, Taiwan]. Numerical illustrations demonstrate the efficiency and accuracy of the proposed scheme on four benchmark exterior wave examples.

The Local Singular Boundary Method for Solution of Two-Dimensional Advection–Diffusion Equation

2021 ◽  
pp. 2150041
Author(s):  
Karel Kovářík ◽  
Juraj Mužík
Keyword(s):  
Diffusion Equation ◽  
Large Scale ◽  
Sparse Matrix ◽  
Singular Boundary ◽  
Tracer Transport ◽  
Advection Diffusion Equation ◽  
Advection Diffusion ◽  
Boundary Method ◽  
Local Variant ◽  
Singular Boundary Method

This work focuses on the derivation of the local variant of the singular boundary method (SBM) for solving the advection-diffusion equation of tracer transport. Localization is based on the combination of SBM and finite collocation. Unlike the global variant, local SBM leads to a sparse matrix of the resulting system of equations, making it much more efficient to solve large-scale tasks. It also allows solving velocity vector variable tasks, which is a problem with global SBM. This paper compares the results on several examples for the steady and unsteady variant of the advection-diffusion equation and also examines the dependence of the accuracy of the solution on the density of the nodal grid and the size of the subdomain.

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