Flow and sound field analysis of agricultural ultrasonic atomizing nozzle

Jinliang Gong, Meixiang Wang, Yanfei Zhang, Yubin Lan, Kazi Mostafa

Abstract


Abstract: To solve the problem of large size of fog droplets generated in plant protection, which are not conducive to absorption by target plants and result in pollution due to excessive application, an ultrasonic atomizing nozzle suitable for agricultural plant protection was designed.  First, a geometric model of the agricultural ultrasonic atomizing nozzle was established using the Design Modeler module in ANSYS FLUENT.  The FLUENT simulation software program was then employed to simulate the internal flow field of the nozzle, and the internal flow field cloud image and sound pressure for various cavity depths and cavity diameters were investigated.  Finally, the vapor holdup of the flow field inside the nozzle were simulated.  The results indicate that the internal cavity depth and diameter of the agricultural ultrasonic atomizing nozzle affect the generation of a cavitation vortex inside the nozzle and the magnitude of the sound pressure.  As the cavity depth and diameter are increased, the amplitude of sound pressure first increases and then gradually decreases.  The cavity diameter has a stronger influence on the amplitude of sound pressure than the cavity depth does.  The sound pressure amplitude changes marginally with the cavity depth.  Simulation revealed that the ultrasonic intensity is highest and the corresponding atomization effect is strongest when the depth and diameter of the of the resonant cavity are 4 and3 mm, respectively.  When the inlet pressure is 2MPa, the percentage of the flow field of the ultrasonic atomizing nozzle with vapor content higher than 80% is approximately 33.94% higher than that achieved before parameter optimization.  The effective space utilization rate inside the nozzle is improved.

Keywords: ultrasonic atomization, resonant cavity, sound pressure amplitude, vapor content; computational fluid dynamics

DOI: 10.33440/j.ijpaa.20190202.36.

 

Citation: Gong J L, Wang M X, Zhang Y F, Lan Y B, Mostafa K.  Flow and sound field analysis of agricultural ultrasonic atomizing nozzle.  Int J Precis Agric Aviat, 2019; 2(2): 32–37.


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