Non-reflecting boundary conditions applicable to general purpose CFD simulators

✍ Scribed by Hans-Christen Salvesen; Rune Teigland

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 259 KB
• Volume: 28
• Category: Article
• ISSN: 0271-2091
• DOI: 10.1002/(sici)1097-0363(19980915)28:3<523::aid-fld735>3.0.co;2-5

✦ Synopsis

In simulations of propagating blast waves the effects of artificial reflections at open boundaries can seriously degrade the accuracy of the computations. In this paper, a boundary condition based on a local approximation by a plane traveling wave is presented. The method yields small artificial reflections at open boundaries. The derivation and the theory behind these so-called plane-wave boundary conditions are presented. The method is conceptually simple and is easy to implement in two and three dimensions. These non-reflecting boundary conditions are employed in the three-dimensional computational fluid dynamics (CFD) solver FLACS, capable of simulating gas explosions and blast-wave propagation in complex geometries. Several examples involving propagating waves in one and two dimensions, shock tube and an example of a simulation of a propagating blast wave generated by an explosion in a compressor module are shown. The numerical simulations show that artificial reflections due to the boundary conditions employed are negligible.