Thesis (MEng)--University of Stellenbosch, 2000.ENGLISH ABSTRACT: This study investigates the implementation of the finite volume numerical
method applicable to non-orthogonal control volumes and the application of
the method to calculate the thermo-flow field within the collector area of a
solar chimney power generating plant. The discretisation of the governing
equations for the transient, Newtonian, incompressible and turbulent fluid
flow, including heat transfer, is presented for a non-orthogonal coordinate
frame. The standard k - E turbulence model, modified to include rough
surfaces, is included and evaluated in the method.
An implicit solution procedure (SIP-semi implicit procedure) as an alternative
to a direct solution procedure for the calculation of the flow field on nonstaggered
grids is investigated, presented and evaluated in this study. The
Rhie and Chow interpolation practice was employed with the pressurecorrection
equation to eliminate the presence of pressure oscillations on nonstaggered
grids.
The computer code for the solution of the three-dimensional thermo-flow
fields is developed in FORTRAN 77. The code is evaluated against simple
test cases for which analytical and experimental results exist. It is also
applied to the analysis of the thermo-flow field of the air flow through a
radial solar collector.
KEYWORDS:
NUMERICAL METHOD, FINITE VOLUME, NON-ORTHOGONAL, k+-e
TURBULENCE MODEL, SIPAFRIKAANSE OPSOMMING: Die studie ondersoek die implementering van 'n eindige volume numeriese
metode van toepassing op nie-ortogonale kontrole volumes asook die
toepassing van die metode om die termo-vloei veld binne die kollekteerder
area van 'n sonskoorsteen krag aanleg te bereken. Die diskretisering van die
behoudsvergelykings vir die tyd-afhanlike, Newtonse, onsamedrukbare en
turbulente vloei, insluitende hitteoordrag, word beskryf vir 'n nie-ortogonale
koordinaatstelsel. Die standaard k - E turbulensiemodel, aangepas om growwe
oppervlakrandvoorwaardes te hanteer, is ingesluit en geevalueer in die studie.
'n Implisiete oplossings metode (SIP-semi implisiete prosedure) as alternatief
vir 'n direkte oplossingsmetode is ondersoek en geimplimenteer vir die
berekening van die vloeiveld met nie-verspringde roosters. 'n Rhie en Chow
interpolasie metode is gebruik tesame met die drukkorreksie-vergelyking ten
einde ossilasies in die drukveld in die nie-verspringde roosters te vermy.
Die rekenaarkode vir die oplossing van die drie dimensionele termo-vloeiveld
is ontwikkel in FORTRAN 77. Die kode is geevalueer teen eenvoudige
toetsprobleme waarvoor analitiese en eksperimentele resultate bestaan. Die
kode IS ook gebruik om die termo-vloeiveld binne 'n radiale son
kollekteerder te analiseer.
SLEUTELWOORDE:
NUMERIESE METODE, EINDIGE VOLUME, NIE-ORTOGONAAL, k - E
TURBULENSIE MODEL, SI