Repositori URV

Author, as appears in the article.: Fard, Mojtaba Goraki; Stiriba, Youssef; Gourich, Bouchaib; Vial, Christophe; Grau, Francesc Xavier

Department: Enginyeria Mecànica

URV's Author/s: Grau Vidal, Francesc Xavier / Stiriba, Youssef

Keywords: One-equation sgs model Large eddy simulation Euler-euler model Bubble column

Abstract: © 2020 Elsevier B.V. In this work Euler-Euler Large Eddy Simulations (LES) of dispersed turbulent gas–liquid flows in a cylindrical bubble column are presented. Besides, predictions are compared with experimental data from Vial et al. 2000 using laser Doppler velocimetry (LDV). Two test cases are considered where vortical-spiral and turbulent flow regimes occur. The sub-grid scale (SGS) modelling is based on the Smagorinsky kernel with model constant Cs=0.08 and the one-equation model for SGS kinetic energy. The emphasis of this work is to analyse the performance of the one-equation SGS model for the prediction of bubbly flow in a three-dimensional high aspect ratio bubble column (H/D) of 20 and investigate the influence of the superficial gas velocity using the OpenFOAM package. The model is compared with the Smagorinsky SGS model and the mixture k-ε model in terms of the axial liquid velocity, the gas hold-up and liquid velocity fluctuations. The bubble induced turbulence and various interfacial forces including the drag, virtual mass and turbulent dispersion where incorporated in the current model. Overall, the predictions of the liquid velocities are in good agreement with experimental measurement using the one-equation SGS model and the Smagorinsky model which improve the mixture k-ε model in the core and near-wall regions. However, small discrepancies in the gas hold-up are observed in the bubble plume region and the mixture k-ε model performs much better. The numerical simulations confirm that the energy spectra of the resolved liquid velocities in churn-turbulent regime follows the classical −5/3 law for low frequency regions and are close to −3 for high frequencies. More details of the instantaneous local flow structure have been obtained by the Euler-Euler LES model including large-scale structures and vortices developed in the bubble plume edge.

Thematic Areas: Waste management and disposal Safety, risk, reliability and quality Nuclear science & technology Nuclear energy and engineering Nuclear and high energy physics Mechanical engineering Materials science (miscellaneous) Materials science (all) Interdisciplinar General materials science Engenharias iv Engenharias iii Engenharias ii Engenharias i

licence for use: https://creativecommons.org/licenses/by/3.0/es/

ISSN: 00295493

Author's mail: youssef.stiriba@urv.cat francescxavier.grau@urv.cat

Author identifier: 0000-0002-0272-7807 0000-0002-4077-7338

Record's date: 2024-10-12

Papper version: info:eu-repo/semantics/acceptedVersion

Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/

Papper original source: Nuclear Engineering And Design. 369 (110823): 110823-

APA: Fard, Mojtaba Goraki; Stiriba, Youssef; Gourich, Bouchaib; Vial, Christophe; Grau, Francesc Xavier (2020). Euler-Euler large eddy simulations of the gas–liquid flow in a cylindrical bubble column. Nuclear Engineering And Design, 369(110823), 110823-. DOI: 10.1016/j.nucengdes.2020.110823

Entity: Universitat Rovira i Virgili

Journal publication year: 2020

Publication Type: Journal Publications