Simulation of droplet deposition process in multi-layer ultrasonic aeroponic cultivator based on CFD discrete phase model

Abstract

<abstract> <bold>Abstract.</bold> Droplet concentration field in root zone were crucial even vital factors which influence aeroponic efficiency of multi-layer aeroponic cultivator, while droplet deposition was viewed as key parameter of droplet concentration field. In order to analyze the effect on the droplet deposition made by the wind speed, the discrete phase particle tracking technology based on the CFD theory was applied to get the characteristics of the droplet deposition in different wind speed conditions, and proceed physical prototype test about characteristics of the droplets deposition. With the RNG<inline-graphic id=ID_895d675f-f65d-4984-837a-7434195e9b19 xlink:href=141895348_files/141895348-01.jpg/> model and the standard wall function, internal fog field of multi-layer ultrasonic atomization cultivator were computed by computational fluid dynamics (CFD) method. The numerical code was based on the SIMPLE scheme with the non staggered grid system, and the improved pressure-velocity method. Also, physical experiments of depositions of spraying droplets of three layers were conducted. Numerical simulation results showed that depositions of spraying droplets of three layers varied with different wind speeds. The numerical results were basically consistent with measurement results. This simulation result would be applied to select aeroponic fan used for regulating and controlling droplet deposition around field plant root zone of this type of ultrasonic atomization cultivator by controlling wind speed.