Print Email Facebook Twitter Two-phase air-water flows in hydraulic jumps at low Froude number Title Two-phase air-water flows in hydraulic jumps at low Froude number: Similarity, scale effects and the need for field observations Author Estrella, Jorge (University of Queensland) Wüthrich, D. (TU Delft Hydraulic Structures and Flood Risk; University of Queensland) Chanson, Hubert (University of Queensland) Date 2022 Abstract A hydraulic jump is a region of rapidly-varied flow that is extremely turbulent. While the one-dimensional continuity and momentum principles have been successfully applied to express the relationships between upstream and downstream conditions, the three-dimensional equations cannot be resolved without some complicated turbulence closure, often involving two phases, i.e. air and water. Based upon a new dataset, the current investigation has the double objective of presenting a novel experimental investigation of the air-water flow characteristics in hydraulic jumps with a small Froude number (Fr1 = 2.1) and discussing the potential scale effects involving several Reynolds numbers (0.078 × 105 < Re < 3.05 × 105). Four unique features are the low inflow Froude number Fr1 = 2.1, the wide range of Reynolds numbers tested systematically, the broad amount of air-water flow properties investigated, and the relatively high Reynolds number (Re = 3.05 × 105) achieved in the largest experiment. More than two dozen of parameters were tested systematically under Froude similar conditions. All the data demonstrated that the selection of relevant (air-water) flow property(ies) used to assess similarity and scale effects is most essential. Further the concept of similarity and scale effects must be linked to specific flow conditions. At low Froude number (Fr1 = 2.1), the present results showed that many hydraulic jump properties could not be extrapolated from laboratory study to full scale hydraulic structures without substantial scale effects. These findings have profound implications for engineering design applications, often operating with Reynolds numbers in excess of 105. Subject Froude similarityHydraulic jumpPhysical modellingReynolds numberScale effectsSimilitudeTurbulenceTwo-phase gas-liquid flow To reference this document use: http://resolver.tudelft.nl/uuid:08e355b4-befb-42fd-962d-48e2426321ba DOI https://doi.org/10.1016/j.expthermflusci.2021.110486 Embargo date 2022-03-03 ISSN 0894-1777 Source Experimental Thermal and Fluid Science, 130 Bibliographical note Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Part of collection Institutional Repository Document type journal article Rights © 2022 Jorge Estrella, D. Wüthrich, Hubert Chanson Files PDF 1_s2.0_S0894177721001321_main.pdf 18.18 MB Close viewer /islandora/object/uuid:08e355b4-befb-42fd-962d-48e2426321ba/datastream/OBJ/view