Drag coefficient-Reynolds number transition for gas bubbles rising steadily in viscous fluids

Recently, the author (Rodrigue, 2001) developed a generalized correlation f or the motion of gas bubbles rising steadily in uncontaminated viscous Newt onian fluids of infinite extent. It is the purpose of this note to show tha t this model can be written in an explicit form for the drag coefficient as a function of the Reynolds and Morton numbers. This new correlation is the n used to predict the position of the minimum in a graphical representation of C-D versus Re. It is shown that the model can predict quite nicely this hydrodynamic transition for viscous fluids.