Luo, Q;
Stoesser, T;
Cameron, S;
Nikora, V;
Zampiron, A;
Patella, W;
(2023)
Meandering of instantaneous large-scale structures in open-channel flow over longitudinal ridges.
Environmental Fluid Mechanics
10.1007/s10652-023-09934-0.
(In press).
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Abstract
The results of large-eddy simulations of open-channel flows over spanwise heterogeneous surface ridges at two representative spanwise spacings are presented. Flows at moderate Froude and Reynolds numbers over smooth channel beds with streamwise-orientated rectangular ridges are considered. The ridge spacing has a profound effect on the flow: at small spacing relatively small secondary cells occur, whilst at large ridge spacing secondary cells occupy the entire flow depth. The instantaneous flow features secondary flow instabilities and the meandering of alternating low- and high-momentum regions. The quasi-periodical nature of the meandering of the instantaneous large-scale motion is visualised and quantified for both ridge spacings. Although time-averaged clockwise and counter-clockwise secondary current cells are symmetrical about the ridge-axis, they exhibit quasi-periodical increase and decrease in size as well as lateral and vertical movement in space over the meandering period.
| Type: | Article |
|---|---|
| Title: | Meandering of instantaneous large-scale structures in open-channel flow over longitudinal ridges |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1007/s10652-023-09934-0 |
| Publisher version: | https://doi.org/10.1007/s10652-023-09934-0 |
| Language: | English |
| Additional information: | © 2023 Springer Nature. This article is licensed under a Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/). |
| Keywords: | Open channel flow, Secondary currents, Spanwise heterogeneity, Meandering |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Civil, Environ and Geomatic Eng |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10175375 |
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