On the integral constraint of the pressure Poisson equation for incompressible flows
We illustrate, using analytical and numerical proofs, how a conservative discretisation of the pressure Poisson equation arising out of the discretisation of the incompressible Navier-Stokes equations (on a two-dimensional unstructured non-staggered grid) satisfies the integral constraint on the pre...
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Published in | International journal of computational fluid dynamics Vol. 26; no. 9-10; pp. 489 - 498 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Abingdon
Taylor & Francis
01.10.2012
Taylor & Francis Ltd |
Subjects | |
Online Access | Get full text |
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Summary: | We illustrate, using analytical and numerical proofs, how a conservative discretisation of the pressure Poisson equation arising out of the discretisation of the incompressible Navier-Stokes equations (on a two-dimensional unstructured non-staggered grid) satisfies the integral constraint on the pressure boundary condition without any additional treatment. When discretised in a non-conservative manner, it is seen that the integral constraint is not exactly satisfied, but only to an order
, where
is an appropriate velocity scale. When solved using an iterative method, such as the Bi-Conjugate Stabilised method, it is proved that the vanishing sum of residuals on all points inclusive of the boundary is a consequence of this integral constraint. This result can then be used as a tool to identify whether the discrete integral constraint has been satisfied or not, especially when the pressure is solved as a Neumann problem. |
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ISSN: | 1061-8562 1029-0257 |
DOI: | 10.1080/10618562.2012.723127 |