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Effect of Major Factors on the Spray Characteristics of Ultrasonic Atomizing Nozzle

초음파 미립화 노즐의 분무 특성에 미치는 주요 인자의 영향

  • Jeong, Seon Yong (School of Mechanical Engineering, Chungbuk National University) ;
  • Lee, Kye Bock (School of Mechanical Engineering, Chungbuk National University)
  • 정선용 (충북대학교 기계공학부) ;
  • 이계복 (충북대학교 기계공학부)
  • Received : 2017.03.16
  • Accepted : 2017.06.09
  • Published : 2017.06.30

Abstract

The atomization of a liquid into multiple droplets has many important industrial applications, including the atomization of fuels in combustion processes and coating of surfaces and particles. Ultrasonic atomizing nozzle has a transducer that receives electrical input in the form of a high frequency signal from a power generator and converts that into mechanical energy at the same frequency. Liquid is atomized into a fine mist spray using high frequency sound vibrations. In coating applications, the unpressurized, low-velocity spray reduces the amount of overspray significantly because the droplets tend to settle on the substrate, rather than bouncing off it. The spray can be controlled and shaped precisely by entraining the slow-moving spray in an ancillary air stream using specialized types of spray-shaping equipment. The desired patterns of spray can be obtained using an air stream. To simulate the water mist behavior of an ultrasonic atomizing nozzle using an air stream, the Lagrangian dispersed phase model was employed using the commercial code FLUENT. The effects of the nozzle contraction shape, water droplet size and the pneumatic pressure drop on the spray characteristics were investigated to obtain the optimal condition for coating applications.

Keywords

Atomization;CFD Simulation;Coating;Dispersed Phase Method;Spray

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