Premium
Computations of a laminar backward‐facing step flow at Re =800 with a spectral domain decomposition method
Author(s) -
Keskar Jayant,
Lyn D.A.
Publication year - 1999
Publication title -
international journal for numerical methods in fluids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 112
eISSN - 1097-0363
pISSN - 0271-2091
DOI - 10.1002/(sici)1097-0363(19990228)29:4<411::aid-fld794>3.0.co;2-6
Subject(s) - laminar flow , domain decomposition methods , mathematics , computation , flow (mathematics) , reynolds number , spectral method , chebyshev filter , incompressible flow , boundary value problem , boundary (topology) , domain (mathematical analysis) , benchmark (surveying) , mechanics , mathematical analysis , geometry , algorithm , physics , finite element method , turbulence , geology , thermodynamics , geodesy
The two‐dimensional laminar incompressible flow over a backward‐facing step is computed using a spectral domain decomposition approach. A minimum number of subdomains (two) is used; high resolution being achieved by increasing the order of the basis Chebyshev polynomial. Results for the case of a Reynolds number of 800 are presented and compared in detail with benchmark computations. Stable accurate steady flow solutions were obtained using substantially fewer nodes than in previously reported simulations. In addition, the problem of outflow boundary conditions was examined on a shortened domain. Because of their more global nature, spectral methods are particularly sensitive to imposed boundary conditions, which may be exploited in examining the effect of artificial (non‐physical) outflow boundary conditions. Two widely used set of conditions were tested: pseudo stress‐free conditions and zero normal gradient conditions. Contrary to previous results using the finite volume approach, the latter is found to yield a qualitatively erroneous yet stable flow‐field. Copyright © 1999 John Wiley & Sons, Ltd.