A numerical simulation was performed to investigate the interaction of two bubbles rising side by side in shear-thinning fluid using volume of fluid (VOF) method coupled with continuous surface force (CSF) method. By considering rheological characteristics of fluid

this approach was able to accurately capture the deformation of bubble interface

and validated by comparing with the experimental results. The rising of bubble pairs with different configurations

including horizontal alignment and oblique alignment

was simulated by the method. The influences of the bubble initial distance and the bubble alignment were studied by analyzing the bubble deformation

rising paths and flow fields surrounding bubbles. The results indicate that within certain initial bubble spacing of S

*

3.3 (S

*

S

I

/D

S

I

initial distance between bubbles

and D bubble diameter)

the dynamic interaction between two bubbles aligned horizontally shows repulsive effect that decreases with the increase of initial bubble spacing

but weakens to certain degree by the shear-thinning properties of fluid. However

the interaction between two bubbles aligned obliquely presents a repulsive effect for the small angle involved but an attractive impa

ct for the large one

which is yet strengthened by the rheological characteristics of fluid.