• 제목/요약/키워드: Flame Color

검색결과 108건 처리시간 0.025초

동시 시계열 계측에 의한 예혼합 분무화염 내 유적군 연소기구의 평가 (Evaluation of Combustion Mechanism of Droplet Cluster in Premixed Spray Flame by Simultaneous Time-Series Measurement)

  • 황승민
    • 대한환경공학회지
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    • 제31권6호
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    • pp.442-448
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    • 2009
  • 예혼합 분무화염의 유적군 연소 기구를 평가하기 위하여 레이저 가시화법, MICRO (multi-color integrated Cassegrain receiving optics) 및 PDA (phase Doppler anemometer) 광학계측 시스템을 이용하여 동시 시계열 계측을 실시하였다. 또한 유적군의 군연소수를 실험적으로 산출하여 이론해석에 적용하였을 경우 실제로 관찰되는 군연소 형태와 일치하는지에 대하여 검토하였다. 유적군 단면화상에 의해 확인된 모든 유적군에 대하여 실험적으로 군연소수 $G_c$를 산출한 결과 주로 내부 군연소와 외부 군연소로 분류되었으며 이론해석과 일치하였다. 또한 실제 관찰된 군연소 형태와 그 유적군의 군연소수를 이론해석에 적용한 경우에 군연소 형태가 일치하는 경우와 일치하지 않는 경우가 있었다. 일치하지 않는 원인은 군연소수를 유적의 기하학적 배치만으로 결정한 것이나 현상의 3차원성이 측정 결과에 영향을 미친 것이라고 생각되어진다.

기능성 의복의 인간공학적 평가 체계 개발 및 적용: 방염복의 평가 및 개선 대상 파악 (Development and Application of an Ergonomic Evaluation System for Functional Clothing: Evaluation of Flame-proof Clothing and Identification of Design Problems)

  • 조자영;정정림;연수민;장준호;유희천;김희은
    • 대한인간공학회지
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    • 제26권2호
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    • pp.1-13
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    • 2007
  • Ergonomic methods have been effectively applied to design and evaluation of functional clothing. The goals of the present study are to: (1) develop an ergonomic evaluation system for the systematic analysis of functional clothing and (2) examine the usefulness of the proposed evaluation system by applying to flame-proof clothing. Based on the survey of literature and the brainstorming of experts in clothing design and ergonomics, factors considered for clothing evaluation were selected, classified, and complemented, resulting in an ergonomic clothing evaluation system consisting of four factor categories (clothing construction, user, work and environment, and user response). Using the proposed system, a field survey and a laboratory experiment were conducted for flame-proof clothing to identify its design problems. The field survey to workers found a comprehensive set of problems on the flame-proof clothing design in terms of pattern, textile, and color. The laboratory experiment identified additional design problems using a questionnaire that was developed based on an analysis on the relationship between clothing design components and ergonomic evaluation measures. The present study showed the ergonomic evaluation system and the relationship analysis of clothing design components and ergonomic evaluation measures are of use to identify design problems of functional clothing in a comprehensive and analytic manner.

광계측 기법을 이용한 직분식 디젤 가시화 엔진내의 온도 및 매연 측정에 관한 연구 (A Study on the Measurement of Temperature and Soot in a Visualized D.I Diesel Engine Using the Laser Diagnostics)

  • 한용택;이기형
    • 한국자동차공학회논문집
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    • 제15권5호
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    • pp.38-47
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    • 2007
  • Based upon temperature calibration using the diffusion flame, the temperature and soot concentration of the turbulent flame in a visualized Diesel engine's turbulent flow of flame was qualitatively measured. Two different heads were used to judge the effect of swirl ratio within the combustion chamber. It was possible to measure the highest temperature of the non-swirl head visualized engine which is approximately 2400K, and that the swirl head engine managed up to 2100K. Also, the more the pressure of the spray increases the more the temperature increases due to the improved combustion situation with respect to the visualized diesel engine soot. This experiment also revealed that the KL factor was high where the fuel collided with the walls of the combustion chamber. Moreover the KL factor was high on parts of the chamber where the temperature dropped rapidly.

Measurements of the Burning Velocities of Flamelets in a Turbulent Premixed Flame

  • Furukawa, Junichi;Noguchi, Yoshiki;Hirano, Toshisuke;Williams, Forman A.
    • 한국연소학회지
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    • 제6권2호
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    • pp.65-70
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    • 2001
  • To investigate statistics of flamelet in a turbulent premixed flame and to obtain components of their burning velocities in a vertical plane above a pipe-flow burner, the local motion of flamelets with respect to gas are measured by specially arranged diagnostics, composed of an electrostatic probe with four identical sensors and a two-color four-beam LDV system. With this technique, the three-dimensional local flame-front-velocity vector is measured by the electrostatic probe for the first time, and simultaneously the axial and radial components of the local gas-velocity vector in a vertical plane above the vertically oriented burner are measured by the LDV system. Two components of burning velocities of planar flamelets can be obtained from these results and are found to be distributed over different directions and to range in magnitude from nearly zero to a few times the planar, unstrained adiabatic laminar burning velocity measured in the unburnt gas. It may be concluded from these results that turbulence exerts measurable influences on flamelets and causes at least some of them to exhibit increased burning velocity.

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Measurements of the Burning Velocities of Flamelets in a Turbulent Premixed Flame

  • Furukawa, Junichi;Noguchi, Yoshiki;Hirano, Toshisuke;Williams, Forman A.
    • 한국연소학회지
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    • 제7권2호
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    • pp.62-68
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    • 2002
  • To investigate statistics of flamelet in a turbulent premixed flame and to obtain components of their burning velocities in a vertical plane above a pipe-flow burner, the local motion of flamelets with respect to gas are measured by specially arranged diagnostics, composed of an electrostatic probe with four identical sensors and a two-color four-beam LDV system. With this technique, the three-dimensional local flame- front-velocity vector is measured by the electrostatic probe for the first time, and simultaneously the axial and radial components of the local gas-velocity vector in a vertical plane above the vertically oriented burner are measured by the LDV system. Two components of burning velocities of planar flamelets can be obtained from these results and are found to be distributed over different directions and to range in magnitude from nearly zero to a few times the planar, un strained adiabatic laminar burning velocity measured in the unburnt gas. It may be concluded from these results that turbulence exerts measurable influences on flamelets and causes at least some of them to exhibit increased burning velocity.

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고온ㆍ고압 정적 연소기내 난류 프로판 예혼합 화염의 매연생성에 관한 연구 (A Study on Soot Formation of Turbulent Premixed Propane Flames in n Constant-Volume Combustor at High Temperatures and High Pressures)

  • 배명환
    • 한국자동차공학회논문집
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    • 제9권4호
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    • pp.1-9
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    • 2001
  • The soot yield has been studied by a premixed propane-oxygen-inert gas combustion in a specially designed disk-type constant-volume combustion chamber to investigate the effects of pressure, temperature and turbulence on soot formation. Premixtures are simultaneously ignited by eight spark plugs located on the circumference of chamber at 45 degree intervals in order to observe the soot formation under high pressures. The eight flames converged compress the end gases to a high pressure. The laser schlieren and direct flame photographs for observation field with 10 mm in diameter are taken to examine into the behaviors of flame front and gas flow in laminar and turbulent combustion. The soot volume fraction in the chamber center during the final stage of combustion at the highest pressure is measured by the in situ laser extinction technique and simultaneously the corresponding burnt gas temperature by the two-color pyrometry method. The pressure and temperature during soot formation are changed by varying the initial charge pressure and the volume fraction of inert gas compositions, respectively. It is found that the soot yield increases with dropping temperature and rising pressure at constant equivalence ratio, and that the soot yield of turbulent combustion decreases in comparison with that of laminar combustion because the burnt gas temperature increases with the drop of heat loss.

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딥러닝을 이용한 화재 발생 예측 이미지 분할 (Image Segmentation for Fire Prediction using Deep Learning)

  • 김태훈;박종진
    • 한국인터넷방송통신학회논문지
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    • 제23권1호
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    • pp.65-70
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    • 2023
  • 본 논문에서는 화재로부터 실시간으로 화염과 연기를 감지하고 분할하기 위해 딥러닝 모델을 사용하였다. 이를 위해 의미론적 분할에서 우수한 성능을 보이는 U-NET을 사용하고 다중 클래스를 이용하여 화재의 불꽃과 연기를 구분 하였다. 제안된 기법을 이용하여 학습한 결과, 손실 오차와 정확도 값이 각각 0.0486과 0.97996으로 매우 양호하였다. 객체 감지에 사용되는 IOU 값도 0.849로 매우 좋았다. 학습된 모델을 이용하여 학습에 사용하지 않은 화재 이미지를 예측한 결과, 화재의 불꽃과 연기가 잘 감지되고 분할되었으며, 연기의 색상도 잘 구분되었다. 제안된 기법을 이용하여 화재 예측 및 감지 시스템 구축 등에 사용될 수 있다.

Fire Detection Using Multi-Channel Information and Gray Level Co-occurrence Matrix Image Features

  • Jun, Jae-Hyun;Kim, Min-Jun;Jang, Yong-Suk;Kim, Sung-Ho
    • Journal of Information Processing Systems
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    • 제13권3호
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    • pp.590-598
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    • 2017
  • Recently, there has been an increase in the number of hazardous events, such as fire accidents. Monitoring systems that rely on human resources depend on people; hence, the performance of the system can be degraded when human operators are fatigued or tensed. It is easy to use fire alarm boxes; however, these are frequently activated by external factors such as temperature and humidity. We propose an approach to fire detection using an image processing technique. In this paper, we propose a fire detection method using multichannel information and gray level co-occurrence matrix (GLCM) image features. Multi-channels consist of RGB, YCbCr, and HSV color spaces. The flame color and smoke texture information are used to detect the flames and smoke, respectively. The experimental results show that the proposed method performs better than the previous method in terms of accuracy of fire detection.

다양한 컬러 공간에 따른 영상 내 화염 검출 성능 연구 (A Study on Fire Flame Detection Performance in the Images of Various Color Spaces)

  • 최병수;김정대;도용태
    • 한국멀티미디어학회:학술대회논문집
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    • 한국멀티미디어학회 2012년도 춘계학술발표대회논문집
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    • pp.284-286
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    • 2012
  • There has been increasing attention about the prevention and counter-measure of disasters. Particularly, for the case of fire disaster, early detection reduces the damage caused by fire significantly and effective detection method is important. Since most existing detectors need to be located at a close distance to fire, analyzing camera images to find fire becomes active research topic. In this paper, we analyze the color characteristics of fire images in various color spaces and report the experimental detection results. The best result is 77.8% success rate in YIQ space.

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