Simulação tridimensional de uma coluna de bolhas cilíndrica : análise em sistema bifásico por técnica de velocimetria por imagem de partícula (PIV), shadow imaging e simulação / Three-dimensional simulation of a cylindrical bubble column : analysis in biphase system by technique of particle image velocimetry (PIV), shadow imaging and simulation

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

16/07/2012

RESUMO

This research aims to evaluate the numerical results from Computational Fluid Dynamics (CFD) simulations and experimental results obtained using Particle Image Velocimetry (PIV) and Shadow Imaging in a bubble column of 1m height, diameter of 14,5cm with a gas distributor with 5 holes of 1 mm diameter each one. The system studied was water-air. The study was performed in homogeneous operation regime for the superficial gas velocity of 0.3 cm/s, 0.5 cm/s and 0.7 cm/s. The PIV and shadow imaging experiments were performed under the same operation conditions. For a good flow representation of PIV data it was necessary to treat 2500 photos to the low superficial gas velocities and 3500 photos to the highest superficial gas velocity. For the shadow imaging technique it was necessary to treat 2000 photos for determining the bubble diameters. In the numerical tests two drag models were evaluated: Ishii-Zuber (1979) and Zhang-Vanderheyden (2002); for turbulence the k-? model was used and the bubble diameter used in the simulations was obtained experimentally by the shadow imaging technique. Average axial velocity profiles of fluid obtained experimentally were compared with numerical results. Analysis of Reynolds tensor, turbulent kinetic energy and turbulent intensity were also evaluated. For superficial gas velocities of 0,3 cm/s and 0,5 cm/s both drag models show good agreement with experimental data. For superficial gas velocities of 0,7 cm/s Zhang-Vanderheyden drag model showed better agreement with experimental data.

ASSUNTO(S)

fluidodinâmica computacional (cfd) computational fluid dynamics

Documentos Relacionados