Title: New approach in boundary conditions for incompressible flows using characteristic relations

Authors: Kamiar Zamzamian

Addresses: Department of Mechanical Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran

Abstract: The present study proposes a new characteristic-based wall boundary condition for incompressible Navier-Stokes equations using artificial compressibility correction. Traditionally, ordinary extrapolation from inner cells of domain is used for estimating the pressure on solid walls. It has been shown in this study that by using characteristic boundary condition on solid walls, the convergence rate is improved in comparison with old extrapolating method for pressure estimation especially at high Reynolds numbers. For this purpose, a computer code using characteristic-based (CB) scheme has been developed for numerical tests which were applied for the wide range of Reynolds numbers and grid combinations. While, the CB scheme exhibits substantial convergence delay as has been reported in the literature, using characteristic-based boundary condition can improve its convergence speed. Also, the presented idea was used for calculation of outer boundary conditions and again showed improvements in convergence speed.

Keywords: incompressible flow; artificial compressibility; characteristics; boundary condition; Navier-Stokes equations; solid walls.

DOI: 10.1504/PCFD.2014.060140

Progress in Computational Fluid Dynamics, An International Journal, 2014 Vol.14 No.2, pp.97 - 106

Received: 08 May 2021
Accepted: 12 May 2021

Published online: 28 Mar 2014 *

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