A CFD study of wind patterns over a desert dune and the effect on seed dispersion

dc.contributor.authorJoubert, Eugene C.
dc.contributor.authorHarms, Thomas M.
dc.contributor.authorMuller, Annethea A.
dc.contributor.authorHipondoka, Martin
dc.contributor.authorHenschel, Joe R.
dc.date.accessioned2014-06-24T09:55:22Z
dc.date.available2014-06-24T09:55:22Z
dc.date.issued2012
dc.description.abstractIn the Namib Desert seed distribution is greatly influenced by wind patterns. Existing literature regarding wind patterns over dunes focuses on two-dimensional simulations of flow over simplified dune structures. The three-dimensional geometries of the sand dunes suggests far more complex flow features exist, which are not captured by two-dimensional simulations. Computational fluid dynamics (CFD) was used to reproduce the three-dimensional near surface wind patterns around a dune with the aim to learn more about seed distribution. Field work included terrain mapping, wind speed, direction and temperature metering. The CFD results show the expected two-dimensional flow features of high pressure at the dune toe, low pressure at the crest and flow acceleration up windward slope. Also observed are some three-dimensional flow features such as a spiral vortex near the crest and transverse flow due to crest-line curvature of the dune. It was also observed how the wall shear stress differs due to the three-dimensional shape of the dune. The wall shear stress suggests that seed accumulation is more likely to occur behind trailing (down-wind) crest edges. Particle tracking showed how seeds tend to move over the dune crest and recirculate towards the crest on the lee-side. The study showed that adding the third dimension makes the simulations more complex, adds to computational requirements and increases simulation time but also provides vital flow information which is not possible with two-dimensional simulations.en_US
dc.identifier.citationJoubert, E.C., Harms, T.M., Muller, A., Hipondoka, M., Henschel, J.R., (2012). A CFD study of wind patterns over a desert dune and the effect on seed dispersion. Journal of environmental fluid mechanics, 12, 23-44.en_US
dc.identifier.urihttp://hdl.handle.net/11070/959
dc.language.isoenen_US
dc.publisherSpringer Netherlandsen_US
dc.source.urihttp://link.springer.com/article/10.1007%2Fs10652-011-9230-3en_US
dc.subjectComputational fluid dynamicsen_US
dc.subjectAtmospheric flowen_US
dc.subjectDuneen_US
dc.subjectParticle trackingen_US
dc.titleA CFD study of wind patterns over a desert dune and the effect on seed dispersionen_US
dc.typeArticleen_US
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