Evaluation of interphase drag models for the determination of gas hold-up of an air-water system in a spouted bed using CFD

Issue title: III Congress of Theoretical and Computational Physical Chemistry, 2–4 December 2010, Altos de Pipe, Caracas, Venezuela

Guest editors: Humberto Soscunxy, Fernando Ruettez and Anibal Sierraltaz

Article type: Research Article

Authors: Ortiz, Jaime. A. Riera^a | Zeppieri, Susana^{b; *} | Rojas-Solorzano, Luis^c | Derjani-Bayeh, Sylvana^a

Affiliations: [a] TADiP Group, Department of Thermodynamics and Transport Phenomena, Caracas, Venezuela | [b] Transport Phenomena Group, Department of Thermodynamics and Transport Phenomena, Caracas, Venezuela | [c] Department of Energy Conversion and Transport, Simón Bolívar University, Caracas, Venezuela | [x] Centro Tecnológico, Instituto Venezolano de Investigaciones Científicas, IVIC, Caracas, Venezuela | [y] Departamento de Química, Facultad Experimental de Ciencias, La Universidad del Zulia LUZ, Maracaibo, Venezuela | [z] Centro de Química, Instituto Venezolano de Investigaciones Científicas, IVIC, Caracas, Venezuela

Correspondence: [*] Corresponding author: Susana Zeppieri, Transport Phenomena Group, Department of Thermodynamics and Transport Phenomena, Caracas, Venezuela. Tel.: +58 212 9063758; Fax: +58 212 9063743; E-mail: [email protected].

Abstract: The hydrodynamics of a dispersed air-water system within a spouted column with a concentric draft tube and a conical base is simulated using CFD based on a two-fluid Euler-Euler (E-E) modeling framework and k-𝜀 two-equation turbulence closure. The interaction between the dispersed gas phase and the continuous liquid phase is characterized by bubble-liquid interphase forces (drag, turbulent dispersion and lift forces). The Ishii-Zuber drag model [1] and Grace adjusted drag model [2], the latter represented by: CDGrace,dense = υgpCDGrace, are compared for their capability to match experimental gas hold-up. Numerical results of Reynolds-averaged Navier-Stokes equations with k-𝜀 two-equation turbulence closure model when compared with Pironti experimental data [3] indicated that both drag models, predicted the air hold-up within experimental errors. Furthermore, Ishii-Zuber liquid-gas drag model consistently provided better agreement with experimental results; it correctly determines the hold-up within 0.14%. Numerical agreement with adjusted Grace liquid-gas drag model, is exponent dependent (4⩽p⩽−0.5), turning down that the best computed hold-up is within 0.44% for p=0.5.

Keywords: CFD, interfacial drag models, holdup, spouted bed column, k-ε

DOI: 10.3233/JCM-2012-0414

Journal: Journal of Computational Methods in Sciences and Engineering, vol. 12, no. 4-6, pp. 269-281, 2012