One-dimensional velocity profiles in open-channel flow with intense transport of coarse sediment
The paper deals with laboratory experiments in open-channel flows with intense transport of model sediment (coarse plastic particles) in our new tilting flume. The major objectives of the paper are: 1. to discuss applied measuring methods, 2. to analyze measured velocity profiles. Ad 1. A profile of...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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EDP Sciences
2015-01-01
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| Series: | EPJ Web of Conferences |
| Online Access: | http://dx.doi.org/10.1051/epjconf/20159202120 |
| _version_ | 1818559563100585984 |
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| author | Zrostlík Štěpán Bareš Vojtěch Krupička Jan Picek Tomáš Matoušek Václav |
| author_facet | Zrostlík Štěpán Bareš Vojtěch Krupička Jan Picek Tomáš Matoušek Václav |
| author_sort | Zrostlík Štěpán |
| collection | DOAJ |
| description | The paper deals with laboratory experiments in open-channel flows with intense transport of model sediment (coarse plastic particles) in our new tilting flume. The major objectives of the paper are: 1. to discuss applied measuring methods, 2. to analyze measured velocity profiles. Ad 1. A profile of the longitudinal component of local velocity was measured across the vertical axis of symmetry of a flume cross section using three independent measuring methods (Prandtl tube, Ultrasonic Velocity Profiler, Acoustic Doppler Velocity Profiler). Due to strong stratification of the flow in the flume, parts of the profile are measured in regions of very different local concentrations of sediment (from virtually zero concentration to the maximum concentration of bed packing). This makes measurements complicated, particularly for ultrasonic measuring techniques. Profiles measured using the different techniques are evaluated and mutually compared. Ad 2. The layered character of the flow causes that shapes of velocity profiles tend to be different in the transport layer (rich on transported particles) above the bed and in the solids-free region between the top of the transport layer and the water surface. Shapes of the profiles are analyzed. Particular attention is paid to the logarithmic profile in the solids-free region of the flow cross section. The profile can be handled using the law of the hydraulically-rough wall. In the law, the eroded top of the bed with the transport layer is supposed to be the rough boundary and appropriate values are sought for its variables. |
| first_indexed | 2024-12-14T00:27:10Z |
| format | Article |
| id | doaj.art-ad66035824b349518a650c81205a0777 |
| institution | Directory Open Access Journal |
| issn | 2100-014X |
| language | English |
| last_indexed | 2024-12-14T00:27:10Z |
| publishDate | 2015-01-01 |
| publisher | EDP Sciences |
| record_format | Article |
| series | EPJ Web of Conferences |
| spelling | doaj.art-ad66035824b349518a650c81205a07772022-12-21T23:25:00ZengEDP SciencesEPJ Web of Conferences2100-014X2015-01-01920212010.1051/epjconf/20159202120epjconf_efm2014_02120One-dimensional velocity profiles in open-channel flow with intense transport of coarse sedimentZrostlík Štěpán0Bareš Vojtěch1Krupička Jan2Picek Tomáš3Matoušek Václav4Department of Hydraulics and Hydrology, Czech Technical University in PragueDepartment of Hydraulics and Hydrology, Czech Technical University in PragueDepartment of Hydraulics and Hydrology, Czech Technical University in PragueDepartment of Hydraulics and Hydrology, Czech Technical University in PragueDepartment of Hydraulics and Hydrology, Czech Technical University in PragueThe paper deals with laboratory experiments in open-channel flows with intense transport of model sediment (coarse plastic particles) in our new tilting flume. The major objectives of the paper are: 1. to discuss applied measuring methods, 2. to analyze measured velocity profiles. Ad 1. A profile of the longitudinal component of local velocity was measured across the vertical axis of symmetry of a flume cross section using three independent measuring methods (Prandtl tube, Ultrasonic Velocity Profiler, Acoustic Doppler Velocity Profiler). Due to strong stratification of the flow in the flume, parts of the profile are measured in regions of very different local concentrations of sediment (from virtually zero concentration to the maximum concentration of bed packing). This makes measurements complicated, particularly for ultrasonic measuring techniques. Profiles measured using the different techniques are evaluated and mutually compared. Ad 2. The layered character of the flow causes that shapes of velocity profiles tend to be different in the transport layer (rich on transported particles) above the bed and in the solids-free region between the top of the transport layer and the water surface. Shapes of the profiles are analyzed. Particular attention is paid to the logarithmic profile in the solids-free region of the flow cross section. The profile can be handled using the law of the hydraulically-rough wall. In the law, the eroded top of the bed with the transport layer is supposed to be the rough boundary and appropriate values are sought for its variables.http://dx.doi.org/10.1051/epjconf/20159202120 |
| spellingShingle | Zrostlík Štěpán Bareš Vojtěch Krupička Jan Picek Tomáš Matoušek Václav One-dimensional velocity profiles in open-channel flow with intense transport of coarse sediment EPJ Web of Conferences |
| title | One-dimensional velocity profiles in open-channel flow with intense transport of coarse sediment |
| title_full | One-dimensional velocity profiles in open-channel flow with intense transport of coarse sediment |
| title_fullStr | One-dimensional velocity profiles in open-channel flow with intense transport of coarse sediment |
| title_full_unstemmed | One-dimensional velocity profiles in open-channel flow with intense transport of coarse sediment |
| title_short | One-dimensional velocity profiles in open-channel flow with intense transport of coarse sediment |
| title_sort | one dimensional velocity profiles in open channel flow with intense transport of coarse sediment |
| url | http://dx.doi.org/10.1051/epjconf/20159202120 |
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