ABSTRACT
The paper presents design details of a simulator for replicating rainfall in the form of fine mist during centrifuge tests using specialized air atomizing nozzles. The relevant scaling laws involved in modelling rainfall at high gravities are discussed, with due consideration of unsaturation effects involved during rainwater infiltration. The importance of designing the pressurized water system in the form of Modified Mariotte’s tube is highlighted, and the specialty of the developed actuator over previous air bladder systems used in literature is discussed in detail. Use of modified version of Mariotte’s principle ensured that uniform rainfall intensity could be achieved over entire model surface area at high gravity, and the intensity could be regulated in-flight at any point of time during test to replicate all varieties of real-life natural hazards, ranging from lingering storms to intense cloudbursts. Further, measures adopted to minimize effects of Coriolis force on droplet trajectory are discussed, and the nozzle configuration selected to minimize chances of formation of ‘blind zones’is presented.
