Convergence of the method of fundamental solutions for solving the boundary value problem of modified Helmholtz equation

2004 ◽  
Vol 159 (1) ◽  
pp. 113-125 ◽  
Author(s):  
Xin Li
2015 ◽  
Vol 17 (3) ◽  
pp. 867-886 ◽  
Author(s):  
C. S. Chen ◽  
Xinrong Jiang ◽  
Wen Chen ◽  
Guangming Yao

AbstractThe method of fundamentalsolutions (MFS)is known as aneffective boundary meshless method. However, the formulation of the MFS results in a dense and extremely ill-conditioned matrix. In this paper we investigate the MFS for solving large-scale problems for the nonhomogeneous modified Helmholtz equation. The key idea is to exploit the exponential decay of the fundamental solution of the modified Helmholtz equation, and consider a sparse or diagonal matrix instead of the original dense matrix. Hence, the homogeneous solution can be obtained efficiently and accurately. A standard two-step solution process which consists of evaluating the particular solution and the homogeneous solution is applied. Polyharmonic spline radial basis functions are employed to evaluate the particular solution. Five numerical examples in irregular domains and a large number of boundary collocation points are presented to show the simplicity and effectiveness of our approach for solving large-scale problems.


2009 ◽  
Vol 06 (04) ◽  
pp. 557-567 ◽  
Author(s):  
D. LESNIC ◽  
A. ZEB

In this paper, an inverse internal boundary value problem associated to the biharmonic equation is considered. The problem consists of determining unknown boundary conditions from extra interior measurements. The method of fundamental solutions (MFS) is used to discretize the problem and the resulting ill-conditioned system of linear equations is solved using the Tikhonov regularization technique. It is shown that, unlike the least-squares method, the MFS-regularization numerical technique produces stable and accurate numerical solutions for an appropriate choice of the regularization parameter given by the L-curve criterion.


2013 ◽  
Vol 10 (02) ◽  
pp. 1341005 ◽  
Author(s):  
A. USCILOWSKA ◽  
D. BERENDT

The nonlinear plate dynamics is a subject of investigations across many disciplines. Various models have been proposed. In this paper, one of the models derived by von Karman is under consideration. In this case, the initial-boundary value problem of the dynamics of a plate large deflection is described by two nonlinear, coupled partially differential equations of fourth order with two initial conditions and four boundary conditions given at each boundary point. There are various means of simulating the dynamic response of thin nonlinear plate, to various degrees of accuracy. The proposal of this paper is to implement one of the meshfree methods i.e., the method of fundamental solutions (MFS). The problem is solved in discretized time domain. This discretization is done in a conception of the finite difference method. The nonlinearity of the equations, obtained at each time step, is solved by application of Picard iterations. For each iteration step, a boundary value problem is to be solved. Moreover, the equations at each iteration step are inhomogeneous ones. So, the radial basis function approximation is applied and a particular solution of boundary value problems is obtained. The final solution is calculated by implementation of the MFS. The numerical experiment has confirmed that the proposed numerical procedure gives the solutions with demanded accuracy and is a good tool to solve the considered problem.


Mathematics ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 1114 ◽  
Author(s):  
Ku ◽  
Xiao ◽  
Yeih ◽  
Liu

This paper presents a study for solving the modified Helmholtz equation in layered materials using the multiple source meshfree approach (MSMA). The key idea of the MSMA starts with the method of fundamental solutions (MFS) as well as the collocation Trefftz method (CTM). The multiple source collocation scheme in the MSMA stems from the MFS and the basis functions are formulated using the CTM. The solution of the modified Helmholtz equation is therefore approximated by the superposition theorem using particular nonsingular functions by means of multiple sources located within the domain. To deal with the two-dimensional modified Helmholtz equation in layered materials, the domain decomposition method was adopted. Numerical examples were carried out to validate the method. The results illustrate that the MSMA is relatively simple because it avoids a complicated procedure for finding the appropriate position of the sources. Additionally, the MSMA for solving the modified Helmholtz equation is advantageous because the source points can be collocated on or within the domain boundary and the results are not sensitive to the location of source points. Finally, compared with other methods, highly accurate solutions can be obtained using the proposed method.


Sign in / Sign up

Export Citation Format

Share Document