• Title/Summary/Keyword: 후방조광법

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A Study on the Visualization of Electrohydrodynamic Spray Flow in High DC Voltages (고전압 직류전기장에서 전기수력학적 분무 유동 가시화에 관한 연구)

  • Sung, K.A.
    • Journal of ILASS-Korea
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    • v.11 no.3
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    • pp.131-139
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    • 2006
  • An experimental study was performed to investigate the liquid breakup and atomization characteristics in electrohydrodynamic atomization according to the changing of experimental parameters such as nozzle size, fluid flow, and electrical intensity. An original electrohydrodynamic atomizer equipment was designed and manufactured for the analysis of spray visualization and the exploration of relationship between applied power and the behavior of liquid atomization. The image processing technique by using the back-illumination method was applied to visualize the distilled liquid breakup process and to examine the variation of the droplet size distribution. The results show that the spray modes of electrohydrodynamic atomization are closelyconnected by the strength of the electric stresses at the surface of the liquid film and the kinetic energy of the liquid jet leaving the needle tip.

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An Experimental Study on the Atomization Characteristics of Electrohydrodynamic for Ethanol($C_2H_5OH$) Fuel (에탄올($C_2H_5OH$) 연료의 전기수력학적 미립화 특성에 관한 실험적 연구)

  • Sung, K.A.
    • Journal of ILASS-Korea
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    • v.14 no.2
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    • pp.65-70
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    • 2009
  • An experimental study was performed to explore the atomization characteristics as the drop formation and the liquid breakup of an ethanol fuel using an electrohydrodynamic atomizer. A developed electrohydrodynamic atomizer controlled by a high AC power, a variable frequency, and a liquid feeding was used for the experiments. The test had been considered a disperse atomization processing at $450{\sim}4200V$ applied power, $200{\sim}400\;Hz$ frequency, and $1{\sim}3\;ml/min$ ethanol feeding to achieve an uniformed droplet formation. The goal of the research was to investigate the possibility of the liquid breakup for an ethanol fuel in an electrohydrodynamic atomizer. The results showed that the mean droplet radius decreased as the applied voltage increased or as the applied AC frequency increased. The whipping motion had been grown at the specified voltages due to the applied frequency.

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An Experimental Study on the Effect of Electrohydrodynamic Monodisperse Atomization According to Nozzle Characteristics (노즐 특성에 따른 전기수력학적 단분산 미립화 효과에 관한 실험적 연구)

  • Sung, K.A.;Lee, C.S.
    • Journal of ILASS-Korea
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    • v.10 no.2
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    • pp.18-31
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    • 2005
  • This study was performed to explore the liquid breakup and atomization characteristics for the classification of drop formation mode and background of uniform droplets generation in electrohydrodynmaic atomization according to the change of experimental parameters such as nozzle material (stainless steel. teflon). fluid flow rate, applied electrical field and intensity, and frequency. In results, from the classification map of drop formation modes according to the variation of applied AC voltage and frequency at a stainless nozzle, the droplet size was smaller than the outer diameter of the nozzle tip relatively in the spindle mode. The transition points became clearly to be moved toward the high applied voltage by rising the applied AC frequency beyond 450Hz. Also the droplet radius can be observed quite small in the frequency bandwidth of $350{\sim}450Hz$. The droplet radiuses decrease as the applied voltage increases for a fixed applied AC frequency within the range from 50Hz to 400Hz Over 400Hz, the relation between the power intensity and the droplet size was not consistent with a continuous mechanism of liquid breakup. Thus, it is showed that the droplet size distribution using the teflon nozzle was analogous to the results of stainless steel, but the droplet size was bigger than that of stainless steel relatively in case of a teflon nozzle.

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