Investigação do escoamento bifásico gás-líquido em uma coluna de bolhas retangular por meio da técnica CFD / Investigation of two-phase gas-liquid flow in a rectangular bubble column using CFD technique

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

12/12/2011

RESUMO

This study aims to evaluate the main forces which act in gas-liquid flow in a rectangular bubble column of dimensions 150cm x 26;4cm x 3;1cm (height (H) x width (W) x depth (D)), with centralized aeration, using CFD technique. The proposed case is based in a experimental study of an air-water system operating in homogeneous bubbly flow, with initial liquid height (Hl) of 79;2cm, corresponding to aspect ratio (Hl /W) of 3. For dispersed phase it was employed a bubble diameter of 4;95mm and a superficial velocity of 2;9cm/s. To validate the model, comparisons with experimental data provided from literature were carried out in transversal sections at four axial levels (Y/Hl = 0;1; 0;2; 0;4; 0;75). To closure the mathematical model, four distinct turbulence models were analyzed to describe the continuous phase (k-- épsilon , RNG k-- épsilon , LRR-RSM, SSG-RSM), as well different correlations to verify the influence of the interfacial forces involved in this type of flow (drag, lift, turbulent dispersion and virtual mass). The consideration of lift and turbulent dispersion in addition to drag force showed meaningful influences in fluid dynamics pattern, while virtual mass force can be neglected. The final complete model tested predicted properly the flow in fully developed regions, according to the experimental pattern

ASSUNTO(S)

bolhas (física) escoamento multifasico fluidodinâmica computacional (cfd) bubble multiphase flow computational fluid dynamics (cfd)

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