Print Email Facebook Twitter Hydraulic jumps with low inflow Froude numbers Title Hydraulic jumps with low inflow Froude numbers: air–water surface patterns and transverse distributions of two-phase flow properties Author Wüthrich, D. (TU Delft Hydraulic Structures and Flood Risk; University of Queensland) Shi, Rui (University of Queensland) Chanson, Hubert (University of Queensland) Date 2022 Abstract Abstract: Hydraulic jumps are commonly employed as energy dissipators to guarantee long-term operation of hydraulic structures. A comprehensive and in-depth understanding of their main features is therefore fundamental. In this context, the current study focused on hydraulic jumps with low Froude numbers, i.e. Fr1 = 2.1 and 2.4, at relatively high Reynolds number: Re ~2 × 105. Experimental tests employed a combination of dual-tip phase-detection probes and ultra-high-speed video camera to provide a comprehensive characterisation of the main air-water flow properties of the hydraulic jump, including surface flow features, void fraction, bubble count rate and interfacial velocities. The current research also focused on the transverse distributions of air-water flow properties, i.e. across the channel width, with the results revealing lower values of void fraction and bubble count rate next to the sidewalls compared to the channel centreline data. Such a spatial variability in the transverse direction questions whether data near the side walls may be truly representative of the behaviour in the bulk of the flow, raising the issue of sidewall effects in image-based techniques. Overall, these findings provide new information to both researchers and practitioners for a better understanding of the physical processes inside the hydraulic jump with low Froude numbers, leading to an optimised design of hydraulic structures. Article Highlights: Experimental investigation of air-water flow properties in hydraulic jumps with low Froude numbersDetailed description of the main air-water surface features on the breaking rollerTransversal distribution of the air-water flow properties across the channel width and comparison between centreline and sidewall. Subject Air–water flow propertiesEnergy dissipationHydraulic jumpHydraulic structuresLow inflow Froude numbersPhase-detection probePhysical modellingSidewall effectsSidewall optical techniques To reference this document use: http://resolver.tudelft.nl/uuid:17b3d061-3eab-430e-8a5b-b01995b42f67 DOI https://doi.org/10.1007/s10652-022-09854-5 ISSN 1567-7419 Source Environmental Fluid Mechanics, 22 (4), 789-818 Part of collection Institutional Repository Document type journal article Rights © 2022 D. Wüthrich, Rui Shi, Hubert Chanson Files PDF W_thrich2022_Article_Hydr ... lowFro.pdf 5.09 MB Close viewer /islandora/object/uuid:17b3d061-3eab-430e-8a5b-b01995b42f67/datastream/OBJ/view