eprintid: 10116515
rev_number: 19
eprint_status: archive
userid: 608
dir: disk0/10/11/65/15
datestamp: 2020-12-08 10:04:01
lastmod: 2021-11-19 23:30:15
status_changed: 2020-12-08 10:04:01
type: proceedings_section
metadata_visibility: show
creators_name: Nassrullah, S
creators_name: Stubbs, A
creators_name: Stoesser, T
creators_name: Wilson, CAME
title: The Validation of the Logarithmic Velocity Profiles Above Rough-Bed Flows
ispublished: pub
divisions: UCL
divisions: B04
divisions: C05
divisions: F44
keywords: Rough gravel riverbed, Acoustic Doppler Velocimeter (ADV), Rough surface turbulence, Logarithmic velocity
profile, Hydraulically rough flow.
note: This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions.
abstract: Knowledge of rough-bed flows is important for river engineers and environmental scientists alike asmost natural surface water flows are considered within the hydraulically rough flow regime. This study helps our understanding of flow characteristics above a rough gravel riverbed, which in-turn, affect fine sediment and nutrient transport which can have a large impact on aquatic organisms and the ecosystem at large. High velocity flows over rough beds result in increased turbulence intensity and contribute to the suspension of fine sediment. Therefore, the main aim of this study is to validate first-order turbulence statistics in the form of spatially-averaged streamwise velocity profiles of the flow over a highly-porous rough bed at intermediate relative submergence. The experiments were conducted under uniform flow conditions in Cardiff University’s Hydraulics Laboratory using a narrow flume, 10 m long, 0.3 m wide, and 0.3 m deep, equipped with a bed of natural gravel with an average diameter of 20 mm. A side looking Acoustic Doppler Velocimeter (ADV) was used to measure velocity profiles at 40 random locations within the sampling area. The results show that a logarithmic velocity profile is valid for rough-bed flows with a von Karman’s constant of 0.41 and a Nikuradse equivalent sand roughness of between 1.5d and 2d.
date: 2019-09-01
date_type: published
publisher: The International Association for Hydro-Environment Engineering and Research (IAHR)
official_url: http://dx.doi.org/10.3850/38wc092019-0421
oa_status: green
full_text_type: pub
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 1833654
doi: 10.3850/38wc092019-0421
lyricists_name: Stubbs, Alexander
lyricists_id: ASTUB89
actors_name: Dewerpe, Marie
actors_id: MDDEW97
actors_role: owner
full_text_status: public
publication: 38th IAHR World Congress - "Water: Connecting the World"
place_of_pub: Panama City, Panama
event_title: 38th IAHR World Congress
institution: 38th IAHR World Congress
book_title: Proceedings of the 38th IAHR World Congress (Panama)
citation:        Nassrullah, S;    Stubbs, A;    Stoesser, T;    Wilson, CAME;      (2019)    The Validation of the Logarithmic Velocity Profiles Above Rough-Bed Flows.                     In:  Proceedings of the 38th IAHR World Congress (Panama).    The International Association for Hydro-Environment Engineering and Research (IAHR): Panama City, Panama.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10116515/1/THEVALIDATIONOFTHELOGARITHMICVELOCITYPROFILESABOVEROUGH-BEDFLOWS.pdf