This video emphasises the fundamental importance of the Reynolds number on the hydraulic modelling of lare hydraulic structures during major floods. In a study of large hydraulic structure, the requirement for model-prototype compliance implies that both model and prototype fluid flows follow the same rules, i.e. geometric,
kinematic and dynamic similarities, as well as the fundamental principles of conservation of mass, momentum and energy. A true similarity would require for all non-dimensional parameters to be identical in the hydraulic
model and prototype hydraulic structure, including the Froude, Reynolds and Morton numbers. And this is impossible using the same fluids in model and prototype. Instead, basic dimensional analysis emphasises the role of the Reynolds number. Differences in Reynolds numbers between model and prototype would account for potential scale effects in terms of both viscous and capillary processes.
Acknowledgements
Marie COLE (USA)
Ms Ya-Hui CHOU (Brisbane, Australia)
Prof Colin J. APELT (Brisbane, Australia)
References
CHANSON, H. (1997). "Air Bubble Entrainment in Free-Surface Turbulent Shear Flows.“ Academic Press, London, UK, 401 pages (ISBN 0-12-168110-6).
CHANSON, H. (1999). "Physical Modelling of Hydraulics." in "The Hydraulics of Open Channel
Flow: An Introduction." Edward Arnold, London, UK, pp. 261-283.
CHANSON, H. (2004). "The Hydraulics of Open Channel Flow: An Introduction." Butterworth-
Heinemann, 2nd edition, Oxford, UK, 630 pages (ISBN 978 0 7506 5978 9).
CHANSON, H. (2022). "Stepped Spillway Prototype Operation and Air Entrainment: Toward a Better Understanding of the Mechanisms Leading to Air Entrainment in Skimming Flows." Journal of Hydraulic Engineering, ASCE, Vol. 148, No. 11, Paper 05022004, 17 pages (DOI: 10.1061/(ASCE)HY.1943-7900.0002015).
CHANSON, H., and APELT, C.J. (2023). "Environmental Fluid Mechanics of Minimum Energy Loss Weirs: Hydrodynamics and Self-aeration at Chinchilla MEL Weir during the November-December 2021 Flood Event." Environmental Fluid Mechanics, Vol. 23, No. 3, pp. 633-659 (DOI: 10.1007/s10652-023-09926-0).
CHANSON, H. (2024). "Self-aeration on large dam spillways during major floods." Journal of Hydro-environment Research, IAHR, Vol. 54, pp. 26-36 (DOI: 10.1016/j.jher.2024.03.002).
UA-cam video clips by Hubert Chanson
{youtube.com/@Hubert_Chanson}
Froude number {ua-cam.com/video/k1lJDZZ5sUA/v-deo.html}
Reynolds number {ua-cam.com/video/jFXjOnCM0mg/v-deo.html}
Weber number {ua-cam.com/video/T7_Ry3Vq9RQ/v-deo.html}
Morton number {ua-cam.com/video/v64m7oG4iGI/v-deo.html}
Physical modelling in hydraulic engineering (4) Froude similitude {ua-cam.com/video/68oa8noNMTY/v-deo.html}
On the relevance of the Morton number on the hydraulic modelling of free-surface flows {ua-cam.com/video/eo92MBWBAXc/v-deo.html}