Scale effects in high-velocity air-water flows on a stepped spillway

Felder, Stefan and Chanson, Hubert (2015). Scale effects in high-velocity air-water flows on a stepped spillway. In: Arthur Mynett, Proceedings of the 36th IAHR World Congress: Deltas of the Future and What Happens Upstream. 36th IAHR World Congress, The Hague, Netherlands, (2762-2770). 28 June-3 July 2015.

Attached Files (Some files may be inaccessible until you login with your UQ eSpace credentials)
Name Description MIMEType Size Downloads
Author Felder, Stefan
Chanson, Hubert
Title of paper Scale effects in high-velocity air-water flows on a stepped spillway
Conference name 36th IAHR World Congress
Conference location The Hague, Netherlands
Conference dates 28 June-3 July 2015
Convener IAHR
Proceedings title Proceedings of the 36th IAHR World Congress: Deltas of the Future and What Happens Upstream
Place of Publication The Hague, Netherlands
Publisher IAHR
Publication Year 2015
Sub-type Fully published paper
Open Access Status Not Open Access
ISBN 9789082484601
Editor Arthur Mynett
Start page 2762
End page 2770
Total pages 9
Collection year 2016
Language eng
Abstract/Summary A comparative analysis of air-water flow properties was performed between two geometrically scaled stepped spillway models with step height of 5 and 10 cm respectively. The experiments were conducted in the same large size facility with chute slope of 26.6° and with the same phase-detection intrusive measurement devices. A full range of macro- and microscopic air-water flow properties was tested for Froude and Reynolds similitudes. Significant scale effects were found in transition and skimming flows. The present finding stressed that the notion of scale effects must be defined in terms of explicit set of air-water flow property(ies). Some air-water flow parameter are more affected by scale effects than others, even in large-size facilities. On one hand, the void fraction and flow bulking are not much sensitive to scale effects. On another hand, the data analyses confirmed scale effects in terms of bubble count rate, turbulence properties and air bubble and water droplet chord sizes, while the present investigation highlighted also scale effects in terms of further airwater flow properties including particle clustering, inter-particle arrival times as well as auto- and cross-correlation functions and time scales respectively. For all air-water flow properties, a close agreement was found between transition and skimming flow outcomes. The findings highlighted that a scaling of the air-water flow properties is rarely possible and measurements at a prototype scale are needed to identify the limitations of scaled air-water flow experiments.
Keyword Stepped spillway
Air-water flows
Physical modelling
Scale effects
Air-water flow properties
Q-Index Code E1
Q-Index Status Provisional Code
Institutional Status UQ
Additional Notes http://app.iahr2015.info/programma_details/2904

Document type: Conference Paper
Collections: School of Civil Engineering Publications
Official 2016 Collection
 
Versions
Version Filter Type
Citation counts: Google Scholar Search Google Scholar
Created: Sat, 21 Nov 2015, 23:23:42 EST by Hubert Chanson on behalf of School of Civil Engineering