A NUMERICAL STUDY ON MOTION OF A SPHERE COATED WITH A THIN LIQUID-FILM AT INTERMEDIATE REYNOLDS-NUMBERS

The steady viscous pow past a sphere coated with a thin liquid film at low and intermediate Reynolds numbers (Re less than or equal to 200) was investigated numerically. The influences of fluid physical propert ies, film thickness, and Reynolds number on the flow pattern were clar ified. Temperature field around the compound drop was also analyzed. T he strong dependence of flow pattern on the characteristics of heat tr ansfer was recognized. The empirical equation of the drag coefficient for the compound drop was proposed. Furthermore, the explicit adaptabi lity of the drag coefficient equation for a gas bubble, a liquid drop, and a rigid sphere in the range of Reynolds number Re less than or eq ual to 1000 was confirmed.