• Title/Summary/Keyword: Mie scattering

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Fuel Concentration Measurements by Laser Rayleigh Scattering (레이저 Rayleigh 산란을 이용한 연료농도의 계측)

  • Kwon, Soon-Tae;Kim, Hyeong-Sig;Lee, Jae-Won;Park, Chan-Jun;Ohm, In-Young
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 2008.04a
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    • pp.199-205
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    • 2008
  • In this study, a system to measure continuously the fuel concentration in a steady flow rig on the basis of Rayleigh scattering is presented. The system can be employed to measure both the temporal and the spatial distribution. Also, it is possible to calibrate the system for the measurement of accurate absolute concentration. Firstly, the system was tested at a calibration chamber for the determination of scattering cross section from propane, butane, acetylene, Freon-12 and Genetron 143a. After this, the system was adapted to a steady flow rig to measure the temporal and spatial fuel concentration. The rig is composed of cylinder head, intake manifold, injector, and transparent cylinder which can simulate internal combustion engine. To cope with the problem of Mie scattering interference, a software filter was developed, which is based on the rise time and the time constant of the photomultiplier-amplifier system. The results show that LRS can provide useful informations about concentration field and the software filter is very effective method to remove Mie interference.

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Fuel Concentration Measurements by Laser Rayleigh Scattering (레이저 Rayleigh 산란을 이용한 연료농도 계측시 잡음원인과 대책)

  • Kwon, Soon-Tae;Lee, Jae-Won;Park, Chan-Jun;Ohm, In-Young
    • Journal of Energy Engineering
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    • v.17 no.4
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    • pp.189-197
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    • 2008
  • In this study, a system to measure continuously the fuel concentration in a steady flow rig on the basis of Rayleigh scattering is presented. The system can be employed to measure both the temporal and the spatial distribution. Also, it is possible to calibrate the system for the measurement of accurate absolute concentration. Firstly, the system was tested at a calibration chamber for the determination of scattering cross section from propane, butane, acetylene, Freon-12 and Genetron 143a. After this, the system was adapted to a steady flow rig to measure the temporal and spatial fuel concentration. The rig is composed of cylinder head, intake manifold, injector, and transparent cylinder which can simulate internal combustion engine. To cope with the interference of Mie scattering, which is main obstacle of the measuring concentration with Rayleigh scattering, a hardware filter was installed for reducing the number density of particles. Furthermore a software filter was developed, which is based on the rise time and the time constant of the photomultiplier-amplifier system. In addition, background noisy was reduced by adjusting the optical array and applying the pin hall and beam trap. The results show that LRS can provide useful information about concentration field and the software filter is very effective method to remove Mie interference.

A Study on the Characteristics of an Evaporating Diesel Spary Using LIEF Technique (LIEF법을 이용한 증발 디젤 분무의 특성에 관한 연구)

  • Kim, Y.R.;Kim, M.S.;Cho, H.;Min, K.D.
    • Journal of ILASS-Korea
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    • v.7 no.3
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    • pp.18-23
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    • 2002
  • An evaporating diesel spray of a common rail lnjector was visualized by LIEF technique. This technique makes it possible to separate the vapor and liquid phase images. The experiment was conducted in a constant volume vessel to make a high temperature and high pressure condition. Three images(vapor and liquid phase images from LIEF and a liquid phase image from Mie scattering) were taken simultaneously in one spray event. The major experimental parameters are the injection pressure and the ambient gas pressure. Also, a relative SMD distribution in a liquid phase was obtained by the ratio of the intensities of the fluorescence and the Mie scattering. The results show that the injection pressure and the ambient gas pressure have a close relation with the spray development and air-fuel muting process.

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Polarized Light Scattering Spectroscopy for Particle Size Measurement on Surface (편광산란분광법을 이용한 표면의 입자 크기 측정)

  • Cho, Hyoung-Jun;Choi, Chi-Kyu;Kim, Doo-Chol;Yu, Young-Hun
    • Korean Journal of Optics and Photonics
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    • v.16 no.6
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    • pp.560-564
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    • 2005
  • We used the polarized light scattering spectroscopy(PLSS) to get selectively the particle size information on a surface in optically diffuse material, and we analyzed the experimental results by Mie scattering theory. We found that the PLSS was the proper method fer getting the surface information in optically diffuse material. This method is able to be used in biotechlology area for diagnostics.

The Spray Characterization Using Planar Imaging Technique (평면 이미지 기법을 이용한 분무 특성 해석)

  • Lee, Kyung-Jin;Jung, Ki-Hoon;Yoon, Young-Bin;Jeong, Kyung-Seok;Jeung, In-Seuck
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.1
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    • pp.93-101
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    • 2000
  • The characteristics of spray nozzle have been quantified with the measurement of fluorescence and Mie scattering images. To correct the attenuation of the incident light sheet, a sequential double-pass light sheet system and the geometrical averaging of two images was implemented. Quantitative mass flux distribution of spray was obtained from fluorescence image. 3-D image is reconstructed using 2-D radial images. Sauter mean diameter (SMD) distribution was determined using the ratio of fluorescence signal intensity and Mie scattering signal intensity and the values were quantified with PDP A data. The measurement of mass flux and SMD using planar imaging technique agee with PDP A data fairly well in the low density region. However, in dense region, there are significant errors caused by secondary scattering. It was found that the planar imaging technique provides many advantages over the point measurement technique, such as PDP A, and can be implemented for quantitative measurement, especially in low density region.

Calculation of Multiple Scattering in Water Cloud and Application in Remote Measurement of Cloud Physical Properties (구름에서의 다중산란효과 계산 및 이를 이용한 구름 물리변수 원격 추출 방법 연구)

  • Kim, Dukhyeon;Park, Sunho;Choi, Sungcheol
    • Korean Journal of Optics and Photonics
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    • v.25 no.1
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    • pp.1-7
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    • 2014
  • Multiple scattering effects in cloud are important error sources of the Mie scattering Lidar inversion method, which should be measured to correct the Lidar equation in single wavelength Mie Lidar. We have calculated the multiple scattering effects in liquid water clouds by using a Monte Carlo method, and we have applied these multiple scattering effects in measuring water cloud effective size and LWC (Liquid Water Content). When cloud effective size is less than $2.5{\mu}m$, we can easily extract cloud effective size and LWC by using two wavelength Lidar such as extinction coefficients measured at 355nm and 1064nm. For a larger size cloud, we can find that saturated degree of linear polarization is strongly correlated with cloud effective size, LWC, and extinction coefficients. From these correlations we know that we can measure LWC and cloud effective size if we use single wavelength Rotational Raman Lidar and Mie scattering polarization Lidar.

Analysis of absorption and scattering characteristics of alumina particles using Mie theory (Mie Theory를 이용한 알루미나 입자의 흡수 및 산란 특성 분석)

  • Ko, Ju-Yong;Kim, In-Sun
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.962-967
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    • 2011
  • Radiative properties of alumina particles which is the main element of the plume from booster and kick motor used for increasing thrust and insertion into the orbit is analyzed. In order to derive the wavelength integrated (i.e., gray) emissivity, emission term in radiative transfer equation is rearranged to be able to tie up with the parameters induced from fundamental particle scattering Mie theory. Result shows that derived gray emissivity with optical properties increases with temperature rising.

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A study on the LCD backlight unit using polymer (LCD backlight unit의 고분자 산란형 도광판에 관한 연구)

  • 정일용;박우상
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.578-581
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    • 1999
  • Dot pattern print methods composed of a diffusion film and two prism sheets, have been generally used for backlighting systems of LCDs. However, this methods require complex structures and show high power consumption and optical loss. To improve these disadvantages of conventional backlight units, light guides using highly scattering optical transmissions (HSOT) polymer as scatters, have been introduced. In this study we analyzed multiple scattering effect in light guide by means of Monte carlo simulation based on Mie scattering theory and ray tracing method. As a result it was revealed that scattering intensity depends on the size of scatters. On the other hands, it was shown that scattering efficiency depends on the wavelength of fluorescent lamp as well as the size of scatters.

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Development of Particle Detection Chamber for Particle Counter (미세 입자 계수기를 위한 입자 검출 챔버 개발)

  • Ohm, Woo Yong
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.1
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    • pp.219-224
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    • 2014
  • In this paper, we study the scattering characteristics of particle using Mie scattering based on various variables such as particle size and refraction of particle, wavelength of laser and angle of receiver to get diffuse light. And we consist a optical system for particle detection, then analyzed the characteristics of the optical system. And based on these characteristics, we develop a particle detection chamber for particle counter and shows experiment result.

Spray Visualization Using Laser Diagnostics (레이저 계측법을 이용한 분무 가시화)

  • Yoon Youngbin;Koh Hyeonseok;Kim Dongjun;Khil Taeock
    • Journal of the Korean Society of Visualization
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    • v.3 no.2
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    • pp.3-13
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    • 2005
  • The optical patterantor provides the high resolution and quantitative information of the spray. Fuel distribution and Sauter Mean Diameter (SMD) can be measured from fluorescence and Mie-scat-tering images. To correct the attenuation of the laser beam and signal in dense spray region, the method to find the geometric mean of the signal intensities obtained from two cameras was evaluated and verified in a solid-cone spray. In high pressure environment, the increased number density of the droplets cause multiple scattering. The optical patternation technique using a laser beam instead of a laser sheet was applied to minimize the multiple scattering problem. The pattern of a coaxial spray was changed from hollow-cone to solid-cone shape, and the spray angle was reduced as the ambient pressure increased from 0.1 to 4.0 MPa.

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