Start Date
6-29-2016 1:30 PM
End Date
6-29-2016 3:30 PM
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Zhang, G., Chanson, H. (2016). Turbulence and Energy Dissipation in the Developing Non-Aerated and the Fully-Developed Aerated Flows on a Stepped Spillway. In B. Crookston & B. Tullis (Eds.), Hydraulic Structures and Water System Management. 6th IAHR International Symposium on Hydraulic Structures, Portland, OR, 27-30 June (pp. 12-21). doi:10.15142/T3640628160853 (ISBN 978-1-884575-75-4).
Abstract
Stepped spillways are characterised by highly turbulent air-water flows and a large rate of energy dissipation compared to smooth chutes. Herein detailed measurements were performed in both the developing non-aerated and fully-developed air-water flow regions on a large 1V:1H stepped spillway model. In the developing flow region, large total pressure fluctuations and turbulence intensities were recorded next to the pseudo-bottom. Downstream of the inception point, large total pressure fluctuations were recorded which were mainly induced by density fluctuations. The water turbulence intensities in the air-water flow region did not differ significantly from those in the developing flow region. The steps generated significant form loss, amounting to about 50% of the upstream total energy regardless of discharge. Similar rates of energy dissipation and friction factors were found between the developing non-aerated and fully-developed air-water flow regions. The energy dissipation on stepped chutes was found to be sensitive to the chute slope, and relatively little affected by the air-bubble diffusion.
Included in
Turbulence and Energy Dissipation in the Developing Non-Aerated and the Fully-Developed Aerated Flows on a Stepped Spillway
Portland, OR
Stepped spillways are characterised by highly turbulent air-water flows and a large rate of energy dissipation compared to smooth chutes. Herein detailed measurements were performed in both the developing non-aerated and fully-developed air-water flow regions on a large 1V:1H stepped spillway model. In the developing flow region, large total pressure fluctuations and turbulence intensities were recorded next to the pseudo-bottom. Downstream of the inception point, large total pressure fluctuations were recorded which were mainly induced by density fluctuations. The water turbulence intensities in the air-water flow region did not differ significantly from those in the developing flow region. The steps generated significant form loss, amounting to about 50% of the upstream total energy regardless of discharge. Similar rates of energy dissipation and friction factors were found between the developing non-aerated and fully-developed air-water flow regions. The energy dissipation on stepped chutes was found to be sensitive to the chute slope, and relatively little affected by the air-bubble diffusion.