MODELLING OF COLLISIONAL BED LOAD AT HIGH BED SHEAR
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F18%3A00323772" target="_blank" >RIV/68407700:21110/18:00323772 - isvavai.cz</a>
Result on the web
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DOI - Digital Object Identifier
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Alternative languages
Result language
angličtina
Original language name
MODELLING OF COLLISIONAL BED LOAD AT HIGH BED SHEAR
Original language description
Sediment-laden turbulent flow at high bed shear in an open channel with a mobile bed is discussed. The bed surface is plane, fully mobilized (bed Shields parameter between 0.4 and 2.0 approximately) and interacts with a developed transport layer in which transported sediment grains are supported by mutual collisions. The transport layer occupies a considerable part of the flow depth. The distribution of grains across the transport layer exhibits a steep gradient of local granular volumetric concentration between the top of the layer (the local concentration is virtually zero) and the bottom of the layer (the local concentration approaches the bed concentration). This affects behavior of flow carrying the collisional load. A granular-rheology based modeling approach is presented which enables to predict the collisional bed-load flow rate and other relevant parameters of a layered structure of the sediment-laden flow. The approach employs granular constitutive relations and conditions at layer interfaces to mutually relate the flow slope, depth, the thickness of the layers and flow rates of both the sediment and sediment-water mixture. Model predictions are compared with experimental results obtained for lightweight granular materials in a laboratory tilting flume. The experimental results include detailed profiles of the longitudinal velocity. Corresponding concentration profiles are derived from the measured velocity distribution, sediment flow rate and thickness of the collisional layer.
Czech name
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Czech description
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Classification
Type
O - Miscellaneous
CEP classification
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OECD FORD branch
20101 - Civil engineering
Result continuities
Project
<a href="/en/project/GA16-21421S" target="_blank" >GA16-21421S: Analysis of Granular-Liquid Channel Flows based on Kinetic Theory Approach</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2018
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů