Hw. Hoogstraten et al., A NUMERICAL-MODEL OF THE FLOW PAST A SPHERICAL-CAP BUBBLE RISING IN AFLUIDIZED-BED, Industrial & engineering chemistry research, 37(1), 1998, pp. 247-252
The shape and motion of gas bubbles in a fluidized bed are investigate
d by considering a single spherical-cap bubble rising vertically with
free slip at its surface in an incompressible Newtonian fluid. The bub
ble shape, its terminal rise velocity, and the flow pattern around the
bubble have been computed numerically by use of a finite element pack
age salving-the Navier-Stokes flow equations. Comparison with experime
ntal findings shows that the bubble shape and the wake fraction can be
predicted satisfactorily for a range of bubble sizes by assuming that
the fluidized bed behaves as a Newtonian fluid. However, a clear-cut
discrepancy was found in the terminal rise velocity. The results indic
ate that this discrepancy cannot be fully explained from the a priori
assumption of the spherical-cap bubble shape, but that, most probably,
Newtonian fluid behavior must be invoked.