Flow Falling from Slit and Circular Hole Over a Horizontal Cylinder

Falling liquid film on the outside surface of a horizontal cylinder is commonly used to facilitate heat transfer process in heat exchangers where wettability is an important factor. Experimental study has been conducted to investigate the wetting area and its dependencies on the various parameters which affect the flow over the horizontal cylinder. Sugar solutions of different concentrations, and hence, different viscosities are used to create the flow over a horizontal cylinder and the images of the flow over the surface are captured. Flow images are then analyzed using edge detection algorithm to calculate the wetting area. It is observed that the wetting area increases linearly with the ratio of the jet diameter at impact to cylinder diameter irrespective of the viscosity of the fluid or flow Reynolds number for both circular and rectangular films.