Secondary currents in turbulent flows over rough walls
Lead Research Organisation:
University of Aberdeen
Department Name: Engineering
Abstract
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Publications
Proust S
(2022)
Shallow mixing layers over hydraulically smooth bottom in a tilted open channel
in Journal of Fluid Mechanics
Zampiron A
(2022)
Flow development in rough-bed open channels: mean velocities, turbulence statistics, velocity spectra, and secondary currents
in Journal of Hydraulic Research
Cameron S
(2022)
Theoretical description of PIV measurement errors
in Acta Geophysica
Luo Q
(2023)
Meandering of instantaneous large-scale structures in open-channel flow over longitudinal ridges
in Environmental Fluid Mechanics
| Description | The channel length required for the development of the flow, from the channel entrance to full establishment, is often a prerequisite when designing hydraulic structures or planning research experiments in open channels. However, the information on the flow development length (LD) is scarce, and even its definition remains vague. In hydraulic experiments, this lack of knowledge introduces great uncertainty, often making comparisons of findings from different studies questionable. This paper offers a physics-based definition for LD, and reports results of systematic laboratory studies to provide guidance on its quantitative assessment. Our data for uniform flows suggest that up to 100 flow depths (H) are required for mean velocity field (including sidewall secondary currents), turbulent stresses (except streamwise variance), velocity skewness and kurtosis, and depth-scale largescale- motions to become essentially independent of the streamwise coordinate. However, very large-scale-motions, streamwise velocity variance, and roughness-induced secondary currents are found to require longer LD of around 150H. Published in Journal of Hydraulic Research, 2023.61(1), "Flow development in rough-bed open channels: mean velocities, turbulence statistics, velocity spectra, and secondary currents" |
| Exploitation Route | Not yet |
| Sectors | Aerospace, Defence and Marine,Environment |
| URL | http://tandfonline.com/doi/full/10.1080/00221686.2022.2132311 |
| Description | Melbourne |
| Organisation | University of Melbourne |
| Country | Australia |
| Sector | Academic/University |
| PI Contribution | Our group shares experimental data on fixed and mobile bed granular flows in water channels to support physical interpretation of wind-tunnel experiments conducted by Professor Ivan Marusic and his group. This is ongoing collaboration within EP/K041088/1 "Bed friction in rough-bed free-surface flows: a theoretical framework, roughness regimes and quantification". |
| Collaborator Contribution | Professor Ivan Marusic and his group helped with planning, methodology, and interpretations, contributing at all project stages for EP/K041088/1 "Bed friction in rough-bed free-surface flows: a theoretical framework, roughness regimes, and quantification". The collaboration is ongoing. |
| Impact | Two successful EPSRC research proposals have resulted from discussions with Professor Ivan Marusic (EP/K041088/1 "Bed friction in rough-bed free-surface flows: a theoretical framework, roughness regimes, and quantification"; EP/V002414/1 "Secondary currents in turbulent flows over rough walls"). |
| Start Year | 2014 |
| Description | Shallow turbulent flows and mixing layers |
| Organisation | French National Institute of Agricultural Research |
| Department | INRA Versailles |
| Country | France |
| Sector | Academic/University |
| PI Contribution | Data analysis and interpretation in relation to turbulence structure |
| Collaborator Contribution | Extensive laboratory experiments, data handling, analysis and interpretation |
| Impact | Proust, S., Nikora, V. Compound open-channel flows: effects of transverse currents on the flow structure. Journal of Fluid Mechanics, 2020, 885, A24 3. Proust, S., Berni, C., Nikora, V. Shallow mixing layers over hydraulically smooth bottom in a tilted open channel. Journal of Fluid Mechanics 2022, 951, A17 |
| Start Year | 2016 |
| Description | Public lectures |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Postgraduate students |
| Results and Impact | The talks have focused on career development of emerging researchers and its enhancement through research publications in specialized peer-reviewed journals I received feedback from a number of early stage researchers that after my talks their publication style has sharply improved. |
| Year(s) Of Engagement Activity | 2014,2015,2016,2017,2021,2022 |