3D near‐bed flow field measurements at low sediment transport rates
2010 (English)In: / [ed] Dittrich, Koll, Aberle & Geisenhainer, Bundesanstalt für Wasserbau , 2010, 785-792 p.Conference paper (Refereed)
Experimental tests were carried out using a gravel bed in a tilting flume and a three camera 3D Particle Image Velocimetry (PIV) system. Sediment movement at variable transport rates was surveyed at the grain scale under uniform flow conditions. A natural river gravel with a well sorted sediment was used. This was subject to steady, uniform flows that generated a range of shear stresses that mobilized the sediment. 3D flow field measurements were made over a plane located few millimeters above the original sediment bed. Image processing and cross-correlation techniques were used to obtain high resolution spatial and high-frequency temporal information of flow velocities. Sequences of images of the bed surface were taken simultaneously with the flow field measurements using an additional camera. An experimental approach is illustrated which links grain behavior with local velocity patterns. Such patterns of velocity can be either in terms of the three velocity components or in terms of the relevant time averaged Reynolds stresses. The potential is shown to develop statistically significant relationships which could describe the stochastic nature of sediment transport at different flow conditions.
Place, publisher, year, edition, pages
Bundesanstalt für Wasserbau , 2010. 785-792 p.
3D PIV, grain entrainment, sediment transport
Ocean and River Engineering Oceanography, Hydrology, Water Resources
IdentifiersURN: urn:nbn:se:kth:diva-81634ISBN: 78-3-939230-00-7OAI: oai:DiVA.org:kth-81634DiVA: diva2:497710
River Flow 2010, International Conference on Fluvial Hydraulics
Qc 201202132012-02-132012-02-102012-02-13Bibliographically approved