• Title/Summary/Keyword: Liquid Atomization

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The Enhacned Atomization of Single Hole Nozzle by Cavitation at The Low Pressure Injection (저압 분사시 캐비테이션에 의한 단공 노즐의 미립화 향상)

  • Son, Jong-Won;Cha, Keun-Jong;Kim, Duck-Jool
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.952-957
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    • 2001
  • The objectives of this investigation were to obtain an excellent spray by cavitation under the low injection pressure. When cavitation occurs in the nozzle hole, the atomization of the liquid jet enhanced considerably. In this experiments, a acrylic nozzle made the gap and installed the bypass in the nozzle hole was used to enhance the atomization of the liquid jet at the low injection pressure. The liquid flow in the nozzle hole was photographed by a transmitted light using a micro flash. The spray angle was measured macroscope images of PMAS and the Sauter mean diameter was measured PDA system. To measure the pressure of the nozzle hole, pressure transducer was used. The results of this study indicated that enhanced atomization of the liquid jet at the low injection pressure was obtained by making the gap and installing the bypass at the single hole nozzle.

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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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액체미립화에 관한 실험적 연구

  • 이규영;신명순;양옥룡
    • Journal of the korean Society of Automotive Engineers
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    • v.7 no.4
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    • pp.57-66
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    • 1985
  • This paper deals with an experimental study on a liquid atomization to investigate the break- up mechanism of a liquid film flow which is formed by a high speed air flow in parallel direction and an atomization characteristics of a liquid film flow in order to provide the basic data for the development of the twin fluid atomizer. Authors had built the simplified, transparent new devices which can form a uniform thickness of liquid film and an electrical measuring circuit of the liquid film thickness. By introducing the new devices and the measuring circuit, the time variation of a liquid film thickness the mean diameter of the droplets, the droplet size distribution, the degree of the dispersion and the atomization rate of a liquid film are measured experimentally. As the analysis of the study, it can be said the experimental investigation will fairly contribute for further study in this field of study.

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The Transient Phenomena of Fuel Injection Nozzle for Electronic Control SI Engines (SI 機關용 電子制御 燃料噴射노즐의 過渡的 現象)

  • 김신구;김덕줄;이충원
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.2
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    • pp.308-318
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    • 1988
  • The liquid disintegration and characteristics of atomization through the swirl nozzle is affected by injection pressure and injection time when the liquid is injected intermittently. These transient phenomena are investigated by electronic controlled-fuel injection nozzle. The effect of injection conditions on disintegration of liquid injected through nozzle is observed photographically by using delay circuit. Droplet size of the element of the sample is measured by the liquid immersion sampling technique. SMD of droplets is varied with time and is decreased as the injection pressure increases. As the injection pressure increases, the maximum diameter of droplet and diameter of droplet which has the maximum droplet number decrease. Spray angle is not affected on injection pressure and change of spray angle with time is associated with needle movement.

A STUDY ON HTGH-EFFICIENCY ATOMIZATION OF MOLTEN MATERIALS (PART 3 : MECHANISM AND CHARACTERISTICS OF ATOMIZATION) (Atomize법에 의한 용융소재의 고효율 미세화에 관한 연구 (제3보 : 애토마이저의 미립화 기구와 특성))

  • Oh, J.G.;Kwon, S.I.
    • Journal of ILASS-Korea
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    • v.4 no.1
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    • pp.19-26
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    • 1999
  • An experimental study of twin-fluid atomization for powder metallurgy has been conducted using a specially designed atomizer in which liquid is first spread into a thin sheet and then exposed on both sides to high-velocity air. Inner air jet worked for supplying liquid and outer air jets disintegrated liquid sheet. The first result of this study were confined to the effect of atomizing quality through experiments with water. The experimental data will be extend to include the influence of atomizing air velocities on mean particle size through experiments with molten material. An experimental equation on the relationship between SMD and the related parameters was taken out; $$SMD=0.00302\frac{{(\sigma_L\;\rho_L\;D_L)}^{0.5}}{\rho_A(V_1+1.155\;V_2)/2}(1+\frac{W_L}{(W_{A1}/3.33)+W_{A2}})+0.0148(\frac{{\mu_L}^2}{\sigma_L\;\rho_L})^{0.425} \;{D_L}^{0.575}(1+\frac{W_L}{(W_{A1}/3.33)+W_{A2}})^2$$.

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Flow visualization and spray characteristics of twin-fluid atomization with converging-diverging nozzles (축소확대 노즐에 의한 2유체 미립화의 유동가시화 및 분무특성)

  • Park, Byeong-Gyu;Lee, Jun-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.8
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    • pp.1056-1067
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    • 1997
  • Present study visualized flow pattern and investigated spray characteristics of twin-fluid atomization with converging-diverging nozzles. Particle sizes were measured by using the Malvern particle analyzer, and the radial size distributions were evaluated by using the tomographic transform technique. The results show that the SMD generally increases in the radial direction at a prescribed liquid flow rate and the increasing rate in the SMD becomes gradual as atomizing gas pressure increases. The SMD decreases as the liquid flow rate increases at a fixed GLR (gas/liquid mass ratio). The atomization performance of the protrusion-type nozzle turned out to be superior to that of the flush-type. However, in the case of the protrusion-type, flow separation occurs outside the liquid delivery tube when the pressure at the gas nozzle chamber is high enough, which may deteriorate the atomization performance.

Atomization Effect of Supersonic Liquid Jet by a Nozzle L/d of Subscale High-Pressure Injection System (축소형 초고압 분사 시스템의 노즐 L/d에 따른 초음속 액체 제트의 미립화 특성)

  • Shin, Jeung-Hwan;Lee, In-Chul;Kim, Heuy-Dong;Koo, Ja-Ye
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.04a
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    • pp.196-199
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    • 2011
  • Subscale high-pressure injection system which use two-stage light gas gun composed with high-pressure tube, pump tube and launch tube can make supersonic liquid jet. The supersonic liquid jet enhances droplet atomization by shockwave in front of the jet. In this study, the experiments was executed to identify the atomization characteristics of the supersonic liquid jet using straight cone nozzle. SMD which presents the atomization characteristics was decreased from $151.2{\mu}m$ to $52.25{\mu}m$ by increasing of L/d.

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Numerical Simulation for Atomization of Liquid Jet in Venturi Scrubber (벤츄리 스크러버 내의 액체 분사 미립화에 대한 수치적 해석)

  • Pak S. I.;Chang K. S.;Moon Y. W.;Sah J. Y.
    • 한국전산유체공학회:학술대회논문집
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    • 2004.10a
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    • pp.37-41
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    • 2004
  • Liquid injection in a Venturi Scrubber creates great effect on the dust-collection efficiency and operation cost of venturi scrubbers. We have developed a model that can numerically simulate atomization of the liquid jet in the Venturi Scrubber. This simulation consists of models on liquid column, jet surface breakup, column fracture and secondary droplet breakup. These models have been embedded in the KIVA3-V code. We have calculated such parameters as the jet penetration, jet trajectory, droplet size, velocity field and the volume flux distribution. The results are compared with the experimental data in this paper.

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Spray Characteristics of Air-assisted Vortex Nozzle at Low Pressure Condition (공기보조식 와류 노즐의 저압 분무특성)

  • Kim, Woojin;Subedi, Bimal;Choi, Jang-Soo
    • Journal of ILASS-Korea
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    • v.20 no.2
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    • pp.82-87
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    • 2015
  • A nozzle with vortex generator was used to develop the low pressure nozzle with high atomization performance and the nozzle atomized the liquid by centrifugal shear forces. In order to analyze the atomization characteristics, a shadowgraphy method was used and the measurement of droplet size was performed by using laser diffraction analyzer. The liquid injection pressure was fixed as 0.03 bar which is very low pressure and the gas injection pressures were changed from 0 bar to 2.0 bar. As a result, the breakup was achieved at the air injection pressure of 0.25 bar and over. The nozzle with the orifice diameter of 0.4 mm and the orifice gap of 0.25 mm presented small droplet diameters under 50 at the air injection pressure of 0.75 bar.