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Examination of pressure oscillations arising in the computation of cascade flow using a boundary‐fitted co‐ordinate system
Author(s) -
Lapworth B. L.
Publication year - 1988
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/fld.1650080403
Subject(s) - cascade , flow (mathematics) , computation , boundary (topology) , grid , mathematics , mechanics , compressibility , cartesian coordinate system , regular grid , control theory (sociology) , mathematical analysis , geometry , physics , computer science , algorithm , engineering , control (management) , chemical engineering , artificial intelligence
The incompressible flow through a two‐dimensional cascade is computed using the SIMPLE algorithm in a boundary‐fitted co‐ordinate system. With the standard staggered grid arrangement the numerical solution was found to allow localized pressure oscillations to persist adjacent to the periodic boundaries. These oscillations were found to be a consequence of the extended momentum control volumes which are required in this region of the cascade. Such control volumes may be removed by the use of appropriately non‐staggered velocity storage locations, which are also desirable in the boundary‐fitted system since the Cartesian velocity components are no longer related to the grid line orientations. However, this storage permits the propagation of global pressure oscillations, which were previously suppressed by the staggered grid arrangement. This paper attempts to define a solution procedure which uses non‐staggered velocity locations and is able to eliminate the consequent global pressure oscillations. To achieve this aim, two forms of pressure correction scheme were considered. The first implemented the scheme proposed by Vanka et al. but was found to be inadequate in the open part of the cascade, whereas the second employed a modification of the scheme proposed by Rhie and Chow and was found to be successful in all regions of the flow. The results computed using this scheme were compared with the available experiment results.