• 제목/요약/키워드: Spray Column

검색결과 75건 처리시간 0.024초

액주형 동축노즐 분무의 무화특성에 관한 실험적 연구 (An experimental study on the atomizing characteristics of liquid column type coaxial sprays)

  • 노병준;강신재;오제하
    • 오토저널
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    • 제14권5호
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    • pp.41-53
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    • 1992
  • The main purpose of this study is to investigate the atomizing characteristics of a two phase spray by using a liquid column type coaxial nozzle. The experiments have been carried out to analyze the atomization behavior, the droplet size distributions, and the statistical properties of droplet size distributions. Immersion sampling method and the image processing technique were adapted for the measurements of particles, and the distributions of the droplet sizes were statistically analyzed. In the experiments, the mass ratio defined as Mr= $M_{\sigma}$/ $M_{1}$ has been changed from 1.0 to 3.4 and the measurements have been performed along the axis of the spray. As a result of this experimental study, the distributions of droplet size were satisfied with the Log-Normal distributions and arithmetic mean diameter and deviation of mass ratio. Droplet volume-surface mean diameter was denoted by a exponential function of mass-ratio and the exponent was denoted by linear relation according to the central axis from the nozzle. Dispersions, skewness factors and flatness factors had comparatively constant values regardless of mass ratio and location.

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An Experimental Study of the Micro Turbojet Engine Fuel Injection System

  • Choi, Hyun-Kyung;Choi, Seong-Man;Lee, Dong-Hun
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2008년 영문 학술대회
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    • pp.1-5
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    • 2008
  • An experimental study was performed to develop the rotational fuel injection system of the micro turbojet engine. In this system, fuel is sprayed by centrifugal forces of engine shaft. The test rig was designed and manufactured to get droplet information on combustion space. This experimental apparatus consist of a high speed rotational device(Air-Spindle), fuel feeder, rotational fuel injector and acrylic case. To understand spray characteristics, spray droplet size, velocity and distribution were measured by PDPA (Phase Doppler Particle Analyzer) and spray was visualized by using Nd-Yag laser-based flash photography. From the test results, the length of liquid column from injection orifice is controlled by the rotational speeds and Sauter Mean Diameter(SMD) is decreased with rotational speed. Also, Sauter Mean Diameter is increased as increasing mass flow rate at same rotational speeds.

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Cephalosporium acremonium 변이주가 생성하는 Cephalosporin C의 정제 (Purification of Cephalosporin C Produced by Cephalosporium acrernoniurn)

  • 이헌주;손영선;안동호;김현수;현형환
    • 한국미생물·생명공학회지
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    • 제20권2호
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    • pp.178-182
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    • 1992
  • Cephalosporium acremonium CSA-2.8A3 변이주로 부터 생성된 cephaloporin C를 정제하여 산업적 이용을 위해 ultrafiltration으로 균체를 제거하고 수종의 수지공정을 통하여 소디움염 형태의 cephalosporin C를 정제하였으며 역삼투막에 의한 농축과 분무건조를 행하였다. WA-30, HO-20, XAD-2000, SK-1B column chromatography를 통해 90% 이상의 높은 수율과 순도를 얻을 수 있었고, 특히 상기 수지들을 직렬로 연결하여 사용합으로써 수율은 96%까지 올릴 수 있었다.

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초기교란이 액주의 분열기구에 미치는 영향 (An effect of initial disturbance on the breakup mechanism of liquid jet)

  • 석지권;박용국;이충원
    • 한국분무공학회지
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    • 제3권2호
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    • pp.34-41
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    • 1998
  • The present experimental study investigates the effect of an initial disturbance on the breakup mechanism of a liquid column. With varying the maginitude of the inital disturbance, we measure the surface wave of liquid column with adopting laser shadow method and analyze the growth rate of liquid column and breakup frequency. The experimental results show that thebreakup characteristics of liquid column is significantly influenced by the frequency of the initial disturbance. We concluded that the most uniform droplet occurs when the frequency of initial disturbance coincides with the natural frequency of the liquid column.

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음향가진된 횡단류 유동장 내 액체제트의 분무특성 (Spray Characteristics of Liquid Jets in Acoustically-Forced Crossflows)

  • 송윤호;황동현;안규복
    • 한국추진공학회지
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    • 제22권2호
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    • pp.1-10
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    • 2018
  • 본 연구에서는 횡단류 공기유동에 수직으로 분사되는 액체제트의 분열거리와 액주궤적에 대한 음향가진의 영향을 살펴보았다. 이를 위해 단공 원형노즐 분사기를 이용하여 동일한 횡단류 공기속도에서 분사압력과 음향가진의 크기를 변화시켜가며 수류실험을 수행하였다. 또한 음향가진 주파수 기준 12개의 위상각에서 분무 이미지를 얻어 위상각 변화에 따른 영향을 확인하였다. 실험결과 분열길이는 비가진 상태에 비해 음향가진 상태에서 전반적으로 감소하였지만 위상각에 따른 변화는 발견되지 않았다. 본 실험 범위 내에서 음향가진은 수직분사 액체제트의 액주궤적에 거의 영향을 주지 못하였다.

직접접촉식 LNG기화기 응용을 위한 칼럼 열교환기 기포특성에 관한 연구 (The Characteristics of Bubbles in a Column Heat Exchanger for the Application of Direct Contact LNG Evaporator)

  • 김성종;한승탁;김종보
    • 설비공학논문집
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    • 제3권2호
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    • pp.142-151
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    • 1991
  • In the present investigation, it has been proposed to utilize a direct contact heat exchanger as an evaporator to solve the difficulties such as scaling, corrosion and law thermal efficiencies, associated with the conventional evaporator. Liquified nitrozen was utilized as a working fluid to investigate basic natures of bubble dynamics in the evaporator, and spray nozzles were adopted to inject liquified nitrozen into the spray column with varying flow rates of dispersed phase fluids. Experimentations were carried out in the range of $6.54{\times}10^{-4}kg/s$ - 0.030 kg/s for dispersed phase flow rates with one, three and five nozzle holes. Observing the bubble dynamics for the evaporator the feasibility of utilizing a direct contact heat exchanger as a LNG evaporator has been evaluated. The results show that no eruption phenomena was observed in the present investigation with $LN_2$ and the interface between $N_2$ bubbles and water was fully turbulent. It is believed that the high injection velocity of $LN_2$ through the spray nozzles provide good mixing effects for both heat and mass transfers between water and $N_2$ bubbles. Ice was formed on the surface of the spray nozzle for higher $LN_2$ flow rates. However, even in this case, it is observed that the ice was detached as soon as it was formed. Under the present experimental conditions, the shapes of $LN_2$ bubbles were in the spherical-cap region according to the Clift, Grace and Weber Graphs. The height of foam region caused by the breakup of larger bubbles keeps increasing with high injection velocities until it reaches it's maximum height.

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단열식 회전연료 노즐의 오리피스 직경에 따른 분무특성 연구 (A Study of Spray Characteristic with Orifice Diameter for Single Column Rotating Fuel Nozzle)

  • 장성호;최성만
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2009년도 춘계학술대회 논문집
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    • pp.253-256
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    • 2009
  • 350Kw급 이하의 초소형 터보제트엔진에서 연료 미립화 특성을 만족하는 분사시스템을 개발하는 것은 매우 어려운 일이다. 그러나 회전 연료 분사시스템은 복잡한 고압연료펌프 시스템 없이도 엔진축의 원심력만을 이용함으로써 좋은 미립화를 할 수 있다. 이러한 이유로, 직경 40 mm의 매우 작은 회전식 연료 인젝터를 제작하였으며, 여러 가지 크기의 분사 오리피스에 대한 실험을 수행하였다. PDPA 측정 시스템을 사용하여 입자의 크기와 속도, 분무분포를 측정하였다. 실험 결과, 분사 오리피스로부터 분출된 단일 액주의 길이는 회전속도에 의해 제어되며, SMD는 회전수가 증가함에 따라 감소하고, 오리피스의 직경과 오리피스 내부에 생성되는 액막두께에 큰 영향을 받는다.

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광폭면 분무를 위한 2유체 노즐의 분무 특성에 관한 연구 (An Experimental Study on the Spray Characteristics by Twin-Fluid Atomizer for Wide Band Spray)

  • 이중순
    • 한국분무공학회지
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    • 제13권4호
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    • pp.212-219
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    • 2008
  • To develop the twin-fluid atomizer having the excellent performance of painting, the spray characteristics of how a wide area can be painted efficiently by one time spraying were studied in this paper. Spray phenomena are affected by the many factors determining the spray field such as the spraying pressure of gas, the spraying pressure and viscosity of liquid paints, the opening duration of needle valve, the design dimension of nozzle, and so on. As the results of experiments, these factors affecting on spray characteristics were suggested as followings; 1) The optimum spraying pressure of gas was $0.015{\sim}0.02\;kPa$, and the appropriate spraying pressure of liquid paint was 0.01kPa, In these situations, the setting up pressures must be compensated as much as the losing amount of pressure because a decompression occurred when operating valves. 2) The duration of opening the needle valve must be sustained for $1{\sim}2$ seconds to inject gas after spraying the liquid paint. This operating of the needle valve was necessary to avoid the affect on the changing of liquid column length, and to prevent the droplet deposit at the initial time of spraying. 3) The spray tip penetration was gained form the experimental equation, and the effective spraying angle was $85^{\circ}{\pm}5^{\circ}$ just at he appropriate spraying pressure of gas. The distribution of the area sprayed had the variation in $350{\pm}50\;mm$ because of the spraying pressure of gas, the its distance from the spray tip, and the lift of the needle valve.

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발사체 충격 방식을 사용한 초음속 액체 제트의 과도 분무 형상에 관한 연구 (Transient Spray Structures of Supersonic Liquid Jet Injected by Projectile Impact Systems)

  • 신정환;이인철;김희동;구자예
    • 한국분무공학회지
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    • 제17권2호
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    • pp.86-93
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    • 2012
  • The effects of projectile impact system on the transient spray characteristic which is supersonic liquid tip velocity were studied by experimentally. Supersonic liquid jets were generated by impact of a high speed projectile driven by a Two-stage light gas gun. A high speed camera and schlieren optical system were used to capture the spray structures of the supersonic liquid jets. In a case of nozzle assembly Type-A, expansion gases accelerate a projectile which has a mass of 6 grams from 250 m/s at the exit of the launch tube. Accelerated projectile collides with the liquid storage part, then supersonic liquid jets are injected with instantaneous spray tip velocity from 617.78 m/s to 982.54 m/s with various nozzle L/d. However, In a case of nozzle assembly Type-B which has a heavier projectile (60 grams) and lower impact velocity (182 m/s), an impact pressure was decreased. Thus the liquid jet injected at 210 m/s of the maximum velocity did not penetrate a shock wave and fast break-up was occurred. Pulsed injection of liquid column generated second shock wave and multiple shock wave.

횡단류 유동 내 원형 및 타원형 액체제트의 분열길이 (Breakup Lengths of Circular and Elliptical Liquid Jets in a Crossflow)

  • 송윤호;안규복
    • 한국분무공학회지
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    • 제23권1호
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    • pp.9-15
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    • 2018
  • Breakup lengths of circular and elliptical liquid jets in a subsonic crossflow were experimentally studied. Two circular-shaped and four elliptical-shaped plain-orifice injectors, which had different aspect ratios and orifice length to diameter ratios, were used to provide various liquid jet conditions such as steady, cavitation, and hydraulic flip. By varying the injection pressure drop from 1 bar to 6 bar, spray images were taken using a shadowgraph technique. Breakup lengths were measured and analyzed. As the aspect ratio in orifices increased, liquid column breakup lengths normalized by the equivalent diameter were reduced irrespectively of the switching of the major or minor axis to the crossflow. It was also found that when hydraulic flip developed inside the orifice, x-directional breakup lengths more decreased for both circular and elliptical liquid jets.