• Title/Summary/Keyword: Flame Color

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

  • Hwang, Seung-Min
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.6
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    • pp.442-448
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    • 2009
  • To evaluate the combustion mechanism of each droplet cluster downstream of the premixed spray flame, the simultaneous time-series measurements were conducted by using optical measurement system consisting of laser tomography, multi-color integrated Cassegrain receiving optics (MICRO) and phase Doppler anemometer (PDA). Furthermore, the group combustion number of droplet cluster was estimated experimentally, and the combustion mechanism of droplet cluster was examined applying the theoretical analysis. The group combustion number, $G_c$, was experimentally estimated about all droplet cluster verified by planar images, and it was classified into the internal group combustion mode and the external group combustion mode according to the theoretical analysis. It is found that there are cases in which the group combustion number estimated experimentally for droplet cluster agree or disagree with the classification by theoretical analysis. The reason of disagreement is considered due to that the group combustion number was only estimated by the geometrical arrangement of droplets in cluster, and that the actual phenomenon is three-dimensional but the measurement system is two-dimensional.

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

  • Cho, Ja-Young;Jeong, Jung-Rim;Yeon, Soo-Min;Chang, Joon-Ho;You, Hee-Cheon;Kim, Hee-Eun
    • Journal of the Ergonomics Society of Korea
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    • v.26 no.2
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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.

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

  • Han, Yong-Taek;Lee, Ki-Hyung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.5
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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.
    • Journal of the Korean Society of Combustion
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    • v.6 no.2
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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.
    • Journal of the Korean Society of Combustion
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    • v.7 no.2
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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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A Study on Soot Formation of Turbulent Premixed Propane Flames in n Constant-Volume Combustor at High Temperatures and High Pressures (고온ㆍ고압 정적 연소기내 난류 프로판 예혼합 화염의 매연생성에 관한 연구)

  • 배명환
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.4
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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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Image Segmentation for Fire Prediction using Deep Learning (딥러닝을 이용한 화재 발생 예측 이미지 분할)

  • TaeHoon, Kim;JongJin, Park
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.23 no.1
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    • pp.65-70
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    • 2023
  • In this paper, we used a deep learning model to detect and segment flame and smoke in real time from fires. To this end, well known U-NET was used to separate and divide the flame and smoke of the fire using multi-class. As a result of learning using the proposed technique, the values of loss error and accuracy are very good at 0.0486 and 0.97996, respectively. The IOU value used in object detection is also very good at 0.849. As a result of predicting fire images that were not used for learning using the learned model, the flame and smoke of fire are well detected and segmented, and smoke color were well distinguished. Proposed method can be used to build fire prediction and detection system.

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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    • v.13 no.3
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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.

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

  • Choi, Byung-Soo;Kim, Jeong-Dae;Do, Yong-Tae
    • Proceedings of the Korea Multimedia Society Conference
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    • 2012.05a
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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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