Bubble formation in non-Newtonian fluids

The study of bubble formation in non-Newtonian fluids has not been reported in literature in spite of the great industrial uses of these fluids. Recently, Subramaniyan and Kumar (S16) have studied bubble formation under constant flow conditions in fluids following the Ostwald-de-Waele rheological model. The model of Kumar and Kuloor (K16, K18, K19) has been extended to take into consideration the drag variation caused by the complexity of the rheological equation. 

The creeping flow of a sphere in a fluid following Eq. (96) has been ex- 

X is a function of the flow index n. For Newtonian fluids, the value of Xn is unity. 

The total drag on the sphere worked out through Eq. (97) becomes 

The force balance bubble volume equation, on the introduction of the drag term given by Eq. (99) becomes 

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