IMPOSING ‘NO’ BOUNDARY CONDITION AT OUTFLOW: WHY DOES IT WORK?
✍ Scribed by Michael Renardy
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 67 KB
- Volume
- 24
- Category
- Article
- ISSN
- 0271-2091
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✦ Synopsis
In recent work on outflow boundary conditions for Navier-Stokes equations by Papanastasiou et al. (Int. j. numer. methods fluids, 14, 587-608 (1992)) a choice has been proposed which can formally be described as imposing no boundary condition at all. This of course leads to an underdetermined problem at the level of the partial differential equations. However, it yields a well-defined problem at the discrete level and it has been documented that this choice of outflow conditions performs in a way which is superior to more 'standard' artificial boundary conditions. In this paper we analyse a one-dimensional model problem. We shall show that the 'free' boundary condition of Papanastasiou et al. actually imposes an effective boundary condition. This effective boundary condition is identified and its advantages are discussed.