• Title/Summary/Keyword: and hood

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Study on vibration characteristics of low pressure turbine hood resonance in a 500MW thermal power plant (500MW 화력발전소 저압터빈 Hood 공진 특성에 관한 연구)

  • Cho, Cheul-Whan;Cho, Seong-Tae;Koo, Jae-Raeyang;Kim, Hyoung-Suk
    • Journal of Power System Engineering
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    • v.17 no.3
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    • pp.23-27
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    • 2013
  • In this research paper, we study on how to decrease the high vibration of turbine hood casings which are main facilities of power generation industry. Cause of Standard coal-fired power 500MW facilities turbine hoods' high vibration is that Natural frequency of hood casing designed in near domain frequency, when they are making hoods. We investigate to reduce high vibration at hood casing. We use FEM method to found how to avoid resonance, and test to confirm that our FEM result. We Finally attach minium mass plate at hood casing to avoid resonance and high vibration reduce lower $100{\mu}m$.

Body-type Study for Hood Pattern - Focusing on the Shoulder and Shape of the Head - (후드(Hood) 패턴 설계를 위한 체형연구 -머리 및 어깨의 형태를 중심으로-)

  • Sohn, Hee-Soon;Shin, Jang-Hee
    • Journal of the Korea Fashion and Costume Design Association
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    • v.13 no.1
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    • pp.37-46
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    • 2011
  • To design a beautiful hood fitting an unspecific individual, focusing on body parts such as the head, neck and shoulder requires body size and type information, which applied by physical factors like size, types, and movements, etc. These parts consist of complicated types and structures. Accurate information should be a priority due to great individual differences and low correlation with other body parts. However, there is not a lot of detailed physical information nor design methods for hood design. Therefore, the purpose of this study is to select a study sample "hood" which is a recently emerging fashion item and to expand the necessary physical information for pattern design and draw body size of wearing part on Hood like head, cerbical portion and shoulder. Extract factors to consist on types and after divided into several types, a study comparing each type's physical characteristics was conducted. In order to do that, body measurement data have been collected by statistical treatment and analyzed reference with statistical treatment. The results of the study are predicted to be important data to develop various hood designs for the recent fashion trend. Factor analysis was conducted through main composition analysis about direct measured item on human body and index items. The results of factor analysis, composed factors of body type in this research object were extracted in total of 3 factors. To categorize the head, neck and shoulders of women in their early 20s women and determine their characteristics, variances with factor analysis became operative for Cluster analysis. With these clusters, women in their early 20s were categorized into three types. The results of this study are considered to affect largely for higher physical suitability on unspecified individuals when allowed absence of reference and the fact that body size only limited to item 'head circumstance' in terms of making hat and hood in the case of recent Korea. For the future, an experimental study of hood production should be conducted by using basic data from this study.

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Numerical Study of Tunnel Hood to Reduce Micro-Pressure Wave on Conventional Railways (기존선 터널 출구 미기압파 저감을 위한 터널 후드의 수치 해석적 연구)

  • Kim Byeong-Yeol;Kwon Hyeok-Bin;Yun Su-Hwan;Ku Yo-Cheon;Ko Tae-Hwan;Lee Dong-Ho
    • Journal of the Korean Society for Railway
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    • v.8 no.6 s.31
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    • pp.513-519
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    • 2005
  • The Korean Tilting Train eXpress may produced a strong micro-pressure wave in tunnel exit because of large train/tunnel area ration of conventional railways. This micro-pressure wave causes an impulsive noise which is a serious environmental noise pollution near tunnel exit. Tunnel hood can be the method of reducing the micro-pressure wave in tunnel exit. Therefore, parametric studies for tunnel hood are performed with respect to the hood length and size to investigate the effects of the tunnel hood. Also, axi-symmetric unsteady compressible flow solver was used to analyze train-tunnel relative motion. According to the result of numerical analysis, the maximum micro-pressure wave in tunnel exit is reduced by 56% throughout the hood establishment on conventional railways.

Analysis on Durability Performance of Spot Welding by the Status of Over-Slam Bumper in Hood System (후드 오버슬램범퍼 조립 상태에 따른 점용접의 내구성능 영향 분석)

  • Lee, Hyuk
    • Journal of Applied Reliability
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    • v.17 no.4
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    • pp.273-279
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    • 2017
  • Purpose: Recently, Issues on security for vehicles are getting increased all around the world. Especially, hood panel needs to be thinner for the protection of pedestrians. But thinner panel makes durability get worse. So, it is needed to satisfy both of them. Methods: Durability effectiveness will be studied because properties and assembly allowance of over-slam bumper mostly affects durability of hood panel. Overlap of over-slam bumper can be made in production line and it can affect durability of spot welding in hood inner panel. Daguchi method is used to catch the condition in which load gets smaller and location, hardness and quantity of overlap are selected to be factors. Durability effectiveness is analyzed with the factors. Result: the mechanism that affects on spot welding is identified. The test was conducted in both open/close and driving condition and the relation between both conditions is analyzed. Conclusion: The test contributed to durability of hood panel with optimization of over-slam bumper.

A Study of Local Ventilation Design on PC Programm (국소환기 설계의 전산화에 관한 연구)

  • Yoon, Myong Cho
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.3 no.2
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    • pp.213-226
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    • 1993
  • The purpose of this study is to computerize the design of single source for a duct work system which is essential for the improvement of working places. There are different types of hood, such as general hood, push pull hood and canopy hood. And out of these three types, general hood and canopy hood were used as subjects of this study. The software used here was Quattro Pro 123 programm, and the hardware was IBM PS/SX(type 5510-SK4 S/N 83-05164). And the results are tabulated in

    and
    . All of the hazardous factors of working places, except for physical factors, such as noise, vibration, illumination and etc, are control measurement related. In order words, workiong places that have problems with toxic gas, mist, fume, dust, odors, biological factors or wetness can be improved by means of the local ventilation design. However, the reqires very complicate processes, and in the case of canopy hood, particularly, one runs into difficulties due to frequent discrepancies generated from calculations through many processes. Recently, progress of the computer hardware technics has been dazzling, and also the software is development rapidly. As proven in the results of this study, it is good that designs for industrial ventilation systems are readily available for easy use. It is hopeful that young scholars will develop easier and quicker methods for local ventilation designs in the future.

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  • A Study on Inhalation Force Improvements of Ventilation Hood For Removed a Pollution Source (유해물질 제거를 위한 국소배기장치 후드의 흡입력 증가에 관한 연구)

    • Yang, Ho-Dong;Kim, Young-Sun;Oh, Yool-Kwon
      • Proceedings of the KSME Conference
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      • 2007.05b
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      • pp.2327-2332
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      • 2007
    • This study investigates on the inhalation force improvements of hood consisted one of the local ventilation systems attached the new device named as gas-guidance-device for removed a pollution source. The numerical method applying finite element method is calculated the velocity and pressure distributions of a moving fluid at the beginning and the inside of a hood with and without the gas-guidance-device in hood. And, the experimental study is measured the wind velocity using the anemometer at the same condition of numerical study. Also, the optimum shape of gas-guidance-device which is suitable for hood shape derived from the numerical and experimental results. The results of this study is supplied the important data to an industrial field for control of a pollution source in the engineering aspect. Moreover, the introduced technique of hood attached the gas-guidance-device is very useful to remove the harmful materials such as dust and waste happened in the manufacturing factory.

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    Thermoregulatory Responses of Differently Designe Cleanroom Garments (고청정 작업환경에서 방진복 디자인이 인체 생리반응에 미치는 영향)

    • 이윤정;정찬주;정재은
      • Journal of the Korean Society of Clothing and Textiles
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      • v.26 no.6
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      • pp.811-820
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      • 2002
    • The physical responses and subjective sensations of different cleanroom garments were compared in order to discover which cleanroom garment design could minimize pollution of the working environment by dust from the worker, maintain a pleasant microclimate and provide effective thermoregulation. A. Coverall with non-detachable hood, kimono sleeves (front), raglan sleeves (back), raschell net on the bodice B. Coverall with detachable hood, kimono sleeves (front), raglan sleeves (back), raschell net on the bodice C. Separate top with non-detachable hood, kimono sleeves (front), raglan sleeves (back), raschell net on the bodice D. Coverall with non-detachable hood, set-in sleeves, raschell net on the bodice E. Coverall with non-detachable hood, raglan sleeves (back), l00% cotton inner wear (upper body) The results of the experiment were as follows. Because the hood covered the shoulder and the chest areas, the chests temperature of the worker wearing garment E was quite higher than those wearing other garment designs. For fabric that has been coated in order to prevent dust, layered designs should be avoided in order to prevent skin temperature from rising. Compared with layers of underwear, it would be more effective to attach a see-through raschell net which clings to the body. Thermal sensations were also highest in garment E, reinforcing the finding that layered designs should be avoided. Through the experiment, it was found that a new material coverall with a non-detachable hood was effective in minimizing dust, suppressing skin temperature increases, maintaining a superior microclimate and providing pleasant subjective sensations.

    A study on tunnel entry design considering the booming noise resulting from micro-pressure wave (미기압파에 의한 터널출구소음저감을 위한 고속철도 터널형상개선에 관한 연구)

    • 목재균;최강윤
      • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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      • 1997.04a
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      • pp.627-635
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      • 1997
    • In general, the booming noise intensity at tunnel exit is strongly related to the gradient of the compression wave front created by high speed train entering the tunnel. This paper presents some results in relation with the compression wave front produced when the high speed train enters a tunnel. Four kinds of tunnel entrance shape with real dimensions were studied to investigate the formation of compression wave front inside tunnel by train entering tunnel. Computations were carried out using three-dimensional compressible Euler equation with vanishing viscosity and conductivity of fluid. According to the reslts, the flow disturbance occured at tunnel entrance were eliminated by tunnel hood with same cross sectional area. The compression wave front is formed completely at 30-40m from tunnel entrance. The maximum pressure gradient of compression wave front is reduced by 29.8% for the inclined tunnel hood and reduced by 21.5% for the tunnel hood with holes at the top face with tunnel without hood. The length of the inclined hood is 15m and the length of the hood with holes is 20m.

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    A Study on Tunnel Entry Design Considering the Booming Noise Resulting from Micro-Pressure Wave (미기압파에 의한 터널 출구 소음 저감을 위한 고속철도 터널 형상 개선에 관한 연구)

    • 목재균;최강윤;유재석
      • Journal of KSNVE
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      • v.7 no.6
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      • pp.959-966
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      • 1997
    • In general, the booming noise intensity at tunnel exit is strongly related to the gradient of the compression wave front created by high speed train entering the tunnel. This paper presents some results in relation with the compression wave front produced when the high speed train enters a tunnel. Four kinds of tunnel entrance shape with real dimensions were studied to investigate the formation of compression wave front inside tunnel by train entering tunnel. Computations were carried out using three-dimensional compressible Euler equation with vanishing viscosity and conductivity of fluid. According to the results, the flow disturbances occured at tunnel entrance were eliminated by tunnel hood with same cross sectional area. The compression wave front is formed completely at 30-40m from tunnel entrance. The maximum pressure gradient of compression wave front is reduced by 29.8% for the inclined tunnel hood and reduced by 21.5% for the tunnel hood with holes at the top face with tunnel without hood. The length of the inclined hood is 15m and the length of the hood with holes is 20m.

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