Experimental Studies of External Hygrocysts

Abstract

The three-dimensional banding phenomenon that occurs on the outside of single horizontal rotating cylinders covered with a liquid film was experimentally studied. Over 400 data sets from a variety of cylinders and liquids produced an emperical correlation between the number of bands formed and the rotational Reynolds, Weber, and Froude numbers. The average film thickness on the top of the rotating cylinder was found to be independent of the physical properties of the liquid and the centrifugal acceleration of the cylinder. The surface velocity measured in the crown of the bands was found to be nearly the same as that predicted by the steady state unbanded velocity field solution of Moffatt.