Abstract
This paper reports preliminary results of a study that examines the detailed kinematic structure of turbulence in three natural rivers. Bed roughness in these rivers differs considerably thus allowing some clarification of the roughness effects on the structure of turbulent flow. Extensive field experiments with arrays of acoustic Doppler velocimeters provided vertical profiles and maps of bulk turbulence statistics and longitudinal cross-correlations. The data analysis is based on a phenomenological theory for high-Reynolds number flows and also involves the double-average methodology for rough-bed flows and associated flow characterisation. The results support a hypothesis that the bursting period in the logarithmic layer can be characterized by a constant Strouhal number equal to 0.166 (1/6). A characteristic turbulence length-scale, required for scaling considerations, appears to be smaller than the local flow depth and can be estimated by subtracting the thickness of the roughness layer from the flow depth.
| Original language | English |
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| Title of host publication | River Flow 2012 - Proceedings of the International Conference on Fluvial Hydraulics |
| Pages | 113-120 |
| Number of pages | 8 |
| Volume | 1 |
| Publication status | Published - 1 Nov 2012 |
| Event | International Conference on Fluvial Hydraulics, River Flow 2012 - San Jose, Costa Rica Duration: 5 Sept 2012 → 7 Sept 2012 http://sdg.iisd.org/events/river-flow-2012-international-conference-on-fluvial-hydraulics/ (Link to conference website) |
Conference
| Conference | International Conference on Fluvial Hydraulics, River Flow 2012 |
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| Country/Territory | Costa Rica |
| City | San Jose |
| Period | 5/09/12 → 7/09/12 |
| Other | This conference is co-organized by the International Association for Hydro-Environment Engineering and Research, and the Association of Civil Ingineers of Costa Rica. It brings together participants to discuss themes including river hydrodynamics, river morphology and sediment transport and river engineering. Sub-topics to be addressed are: transport of sediment; sedimentation in reservoirs; transport and fate of pollutants in rivers; flow management and flood control; river habitat management and river restoration; and navigation waterways and dredging. River Flow 2012 will be held together for the first time with the XXV IAHR Latin-American Congress on Hydraulics, an event that is taking place from 9-12 September 2012, at the same venue. |
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