Print Email Facebook Twitter Air–water properties of unsteady breaking bore part 2 Title Air–water properties of unsteady breaking bore part 2: Void fraction and bubble statistics Author Shi, Rui (University of Queensland) Wüthrich, D. (TU Delft Hydraulic Structures and Flood Risk; University of Queensland) Chanson, Hubert (University of Queensland) Date 2023 Abstract Continuing from the part 1 (Shi et al., 2022) this paper presents an experimental investigation of transient void fraction and bubble statistics in a highly turbulent breaking bore with Fr1=2.4. The measurements were conducted using a combination of dual-tip phase-detection probes and an ultra-high-speed video camera. The enclosed bubble detection technique (EBDT) used the synchronised probe and camera signals to provide the contour of instantaneous void fraction in the bore roller. The ensemble-averaged void fraction was derived, and compared to analytical solutions of air diffusion models. The bubble statistics were characterised by the bubble clustering properties, pseudo bubble count rate and bubble size spectrum. The clustering data showed the non-random bubble grouping in the shear layer, and the bubble size distributions N(r) followed a commonly adopted bubble break-up model: N(r)∝r−m, where r was the equivalent bubble radius in the present study. The comparison indicated that, in the breaking bore, its air diffusion process was similar to that in a stationary hydraulic jump, and the bubble break-up process was comparable to that in breaking waves. Subject Breaking boreBubble clusteringBubble size spectrumDual-tip phase detection probeImage processingUnsteady gas–liquid flowVoid fraction To reference this document use: http://resolver.tudelft.nl/uuid:0f5bab7b-557c-4cb6-9028-e8d9b68aeee8 DOI https://doi.org/10.1016/j.ijmultiphaseflow.2022.104337 Embargo date 2023-06-11 ISSN 0301-9322 Source International Journal of Multiphase Flow, 159 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 © 2023 Rui Shi, D. Wüthrich, Hubert Chanson Files PDF 1_s2.0_S0301932222002968_main.pdf 5.34 MB Close viewer /islandora/object/uuid:0f5bab7b-557c-4cb6-9028-e8d9b68aeee8/datastream/OBJ/view