An inexpensive, portable rain simulator: construction and test data

Abstract

Construction details of an inexpensive, portable rain simulator are given. The dismountable components are easily transported on a light truck. The flat spray nozzles used produced rain with a >90% coefficient of uniformity over a 1-m² test plot. Drop sizes and drop size distributions were determined using a flour pellet method. The appropriate equation of motion for accelerating drops and drag coefficients were used to calculate the impact velocity of individual drops and the kinetic energy of rain produced by various nozzles. Rainfall intensity can easily be varied in the range 10–150 mm h⁻¹ and water consumption is low.

Keywords:

• Drop size
• infiltration
• rain simulator
• runoff