Using the drift of waterdrops during fall for rainfall simulator design

An investigation of drift of waterdrops falling to terminal velocity showed that impact points 9.75 meters below a drop-former were distributed normally around the geometric center of the impact point pattern. The standard deviations of the normal distributions ranged from 1.04 cm for drops 3.5 mm in diameter to 1.32 cm for those 5.6 mm in diameter. The normal distribution function can be used to predict the variation from uniformity of the point application intensity of a rainfall simulator.