A film of water is flwoing downa vertical wall with a width

A film of water is flwoing downa vertical wall with a width of h1. THere is an air gap(at atmospheric pressure) h2 adjacent to the falling water. Find the size of h2 so that the effect of the air on the water\'s velocity profile can be neglected.

Use coordinate axes such that x points down, y points from the solid/water surface toward the solid air surface, so that y 0 is the water solid surface and y h is the air/liquid interface Neglect the density of the air, and require that the velocity vx and shear stress Ty be continuous at the air water interface. a) Derive the velocity profiles in both the air and the water. b) Identify a criterion that must be satisfied for the velocity profile in the water to yield a shear stress of zero at the air/water interface.

Solution

The answer of following question is as follows.

The velocity profile for the air and the water is parabolic in nature.