A GENERAL EXPRESSION OF BOUNDARY-CONDITIONS IN TLM DIFFUSION MODELING

Citation
X. Gui et al., A GENERAL EXPRESSION OF BOUNDARY-CONDITIONS IN TLM DIFFUSION MODELING, International journal of numerical modelling, 9(6), 1996, pp. 459-461
Citations number
4
Categorie Soggetti
Computer Application, Chemistry & Engineering","Mathematical Method, Physical Science","Engineering, Eletrical & Electronic
ISSN journal
08943370
Volume
9
Issue
6
Year of publication
1996
Pages
459 - 461
Database
ISI
SICI code
0894-3370(1996)9:6<459:AGEOBI>2.0.ZU;2-8
Abstract
We show that the general boundary condition D partial derivative Phi/p artial derivative x + alpha Phi = 0 (D is the diffusion coefficient an d alpha is a constant) in TLM diffusion modelling can be expressed acc urately in terms of a voltage reflection coefficient rho = (Delta x - alpha Delta t)/(Delta x + alpha Delta t), where Delta x is the spatial resolution and Delta t is the time step. Based on this general expres sion, the special cases of short-circuit (rho = -1), open-circuit (rho = 1) and matched-load (rho = 0) boundaries can be described succinctl y by alpha --> infinity, alpha --> 0 and alpha = Delta x/Delta t, resp ectively. This formulation allows for straightforward treatment of mix ed boundary conditions found, for example, in diffusion-drift systems.