Hydraulics of Thin Film Flow

In considering thin-film liquid flow as occurring in a trickling filter, a theoretical expression is developed for the average time of contact of a thin liquid film as it flows steadily around a body of revolution whose axis of symmetry is vertical. Entry at the uppermost and exit at the lowermost points is assumed. The body does not have any sharp corners. Laminar flow is assumed, and surface tension is neglected. Application is made to an ellipsoid of revolution with major axis of major ellipse vertical and to an ellipsoid of revolution with major axis of major ellipse horizontal.