LETTER TO THE EDITOR. A GENERAL EXPRESSION OF BOUNDARY CONDITIONS IN TLM DIFFUSION MODELLING

✍ Scribed by X. GUI; S. K. DEW; M. J. BRETT; D. DE COGAN

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 162 KB
• Volume: 9
• Category: Article
• ISSN: 0894-3370
• DOI: 10.1002/(sici)1099-1204(199611)9:6<459::aid-jnm262>3.0.co;2-y

✦ Synopsis

We show that the general boundary condition DaWax + a@ = 0 (D is the diffusion coefficient and a is a

constant) in TLM diffusion modelling can be expressed accurately in terms of a voltage reflection coefficient p = ( A x -a A t ) / ( A x + aAt),

where Ax is the spatial resolution and At is the time step. Based on this general expression, the special cases of short-circuit ( p = -I), open-circuit ( p = 1) and matched-load ( p = 0) boundaries can be described succinctly by a -a , a-0 and a = Ax/At, respectively. This formulation allows for straightforward treatment of mixed boundary conditions found, for example, in diffusion-drift systems.