• 제목/요약/키워드: SMEP

검색결과 12건 처리시간 0.022초

천장에 열 유속을 갖는 대형 공간에서 화재 발생시 연기거동에 대한 수치해석적 연구 (A Numerical Study of Smoke Movement in Atrium Fires with Ceiling Hea Flux)

  • 정진용;유홍선;김성찬;김충익
    • 한국화재소방학회논문지
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    • 제13권4호
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    • pp.20-29
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    • 1999
  • 본 연구는 두 가지 유형의 아트리움 공간에 대해서 Zone모델과 Field모델을 비교하였으며 특히 천장에 열 유속을 갖는 아트리움 화재에 대해서 SMEP화재 모델을 적용하여 연기거동을 수치해석 하였다. Zone 모델로는 NIST에서 개발된 CFAST 그리고 CSIRO에서 개발된 NBTC 1-room 모델을 사용하여 SMEP Field모델을 검증하였다. PISO 알고리즘과 부력항을 포함한 수정 k-e epsilon 난류모델을 사용한 SMEP은 연속, 운동, 에너지 그리고 농도 방정식을 풀었으며, 상용 Zone 모델들과의 비교는 서로 유사한 결과를 보였다. 천장이 유리로 만들어진 아트리움의 경우, 태양열에 의한 천장 열 유속을 고려함으로써 좀더 실제적인 화재현상을 규명할 수 있다. 수치해석결과 천장 열 유속 조건은 연층의 온도 분포에는 영향을 미치지만 연기의 하강과 거동에는 커다란 영향을 미치지 않고 있음을 확인 할 수 있었다. 따라서 화재 감지기나 배연 설비 시스템의 설치시 이러한 점들이 고려되어야만 한다.

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실내화재에서 연기거동에 미치는 복사영향에 대한 수치해석적 연구 (A Numerical Study of Radiation Effect under Smoke Movement in Room Fire)

  • 정진용;유홍선;홍기배
    • 한국화재소방학회논문지
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    • 제14권3호
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    • pp.6-12
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    • 2000
  • 본 연구는 두 가지 유형의 3차원 실내 공간 내에서 화재 발생시 연기거동에 미치는 복사영향을 알아보기 위해 자체개발한 SMEP(Smoke Movement Estimating Program) Seld 모델을 사용하여 수치해석하였다. PISO 알고리즘과 부력항을 포함한 수정 k - e 난류모델을 사용한 SMEP은 연속, 운동, 에너지, 농도 그리고 복사 열 전달 방정식을 풀었으며, 복사 열 전달 방정식의 해석을 위하여 S-N 구분종좌표법을 채택하여 사용하였다. 수치해석 결과 연기의 온도분포는 복사를 고려하지 않고 대류만을 고려했을 경우 실험치와 많은 오차를 보였으나 복사를 함께 고려했을 경우는 실험치와 작은 오차범위로 비슷한 경향을 나타내었다. 이것은 연기속에 포함되어 있는 연소생성물 중 H2O와 CO2 가스의 복사 영향 때문이며, 따라서 좀더 실제적인 화재해석에 있어서 복사는 반드시 고려되어야만 한다.

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A Study on the Radiation Effect of the Smoke Movement in Room Fires

  • Jeong, Jin-Yong;Ryou, Hong-Sun
    • International Journal of Air-Conditioning and Refrigeration
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    • 제10권3호
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    • pp.162-175
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    • 2002
  • To investigate smoke movement with radiation in a room fires, a numerical and experi-mental analysis were performed. In this paper, results from a field model based on a self-developed SMEP (Smoke Movement Estimating Program) were compared with Stockier's ex-periment and the experiments on various sized pool fires in a room with door The SMEP using PISO algorithm solves conservation equations for mass, momentum, energy and species, together with those for the modified k- $\varepsilon$ turbulence model with buoyancy term. Also it solves the radiation equation using the S-N discrete ordinates method (DOM). The result of the cal-culated smoke temperature considering radiation effect has shown good agreement compared with the experimental data, although there are large discrepancy in the hot smoke layer be-tween the temperature predicted by the SMEP with only convection effect and obtained by the experimental result. This large discrepancy is caused from the radiation effect of $H_2O$ and $CO_2$ gas under smoke productions. Hence the radiation effect under smoke in fire is the point to be specially considered in order to produce more realistic result.

아트리움에서 화재 발생시 복사가 고려된 연기거동에 대한 수치해석 연구 (A Numerical Study of Smoke Movement with Radiation in Atrium Fires)

  • 정진용;유홍선;홍기배
    • 한국화재소방학회논문지
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    • 제15권1호
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    • pp.7-15
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    • 2001
  • 본 연구는 3차원 아트리움 공간(일본의 SIVANS 아트리움)내에서 화재 발생시 복사가 고려된 연기의 거동을 알아보기 위해 자체개발한 SMEP(Smoke Movement Estimating Program) Held 모델을 사용하여 수치해석하였다. PISO 알고리즘과 부력항을 포함한 수정 k-$\\varepsilon$ 난류모델을 사용한 SMEP은 연속, 운동, 에너지, 농도 그리고 복사 열 전달 방정식을 풀었으며, 복사 열 전달 방정식의 해석을 위하여 S-N 구분종좌표법을 채택하여 사용하였다. 수치해석 결과 연기의 온도분포는 복사와 대류를 힘께 고려했을 경우가 대류만을 고려했을 경우 보다 실험결과와 근사한 경향을 나타내었다. 이것은 연기속에 포함되어 있는 연소생성을 중 $H_2$O와 $CO_2$ 가스의 복사 영향 때문이며, 따라서 좀더 실제적인 화재해석에 있어서 연기의 복사 영향을 고려하는 것이 필요하다. 또한 연층의 하강 복도는 약 0.l m/s이었으며 피난수준인 바닥 1.5m까지 연층이 도달하는 데에는 56 kW의 Ultra Fast Fire의 경우 약 450초의 시간이 걸렸다.

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A Numerical Study on the Smoke Behavior by Solar Radiation through Ceiling Glass in Atrium Fires

  • Jeong, Jin-Yong
    • International Journal of Air-Conditioning and Refrigeration
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    • 제10권3호
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    • pp.117-128
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    • 2002
  • This paper describes the smoke filling process of a fire field model based on a self-deve-loped SMEP (Smoke Movement Estimating Program) code to the simulation of fire induced flows in the two types of atrium space containing a ceiling heat flux. The SMEP using PISO algorithm solves conservation equations for mass, momentum, energy and species, together with those for the modified k-$\varepsilon$ turbulence model with buoyancy production term. Also it solves the radiation equation using the discrete ordinates method. Compressibility is assumed and the perfect gas law is used. Comparison of the calculated upper-layer average tempera-ture and smoke layer clear height with the zone models has shown reasonable agreement. The zone models used are the CFAST and the NBTC one-room. For atrium fires with ceiling glass the ceiling heat flux by solar heat causes a high smoke temperature near the ceiling. However, it has no effect on the smoke movement such as the smoke layer clear heights that are important in fire safety. In conclusion, the smoke layer clear heights that are important in evacuation activity except the early of a fire were not as sensitive as the smoke layer tem-perature to the nature of ceiling heat flux condition. Thus, a fire sensor in atrium with ceiling glass has to consider these phenomena.

PISO 알고리즘을 이용한 세 가지 형태의 아트리움 공간에서 화재 발생시 연기 거동에 대한 수치해석적 연구 (A Numerical Study of Smoke Movement for the Three Types of Atrium Fires using PISO Algorithm)

  • 정진용;유홍선;김성찬
    • 한국화재소방학회논문지
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    • 제13권1호
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    • pp.21-30
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    • 1999
  • 본 연구는 세 가지 유형의 아트리움 공간에 대해서 Zone 모델과 Field 모델을 비교하였으며, Zone 모델로는 FIRST, CFAST, NIST에서 개발된 CCFM.VENTS 그리고 CSIRO에서 개발된 NBTC 1-room 모델을 사용하였고 Field 모델로는 Chow에 의해 개발된 화재모델과 본 연구에서 개발된 SMEP을 사용하였다. 두 모델들에 대한 비교는 서로 유사한 결과를 보였으며, 특히 PISO 알고리즘을 사용한 SMEP의 경우가 SIMPLER 알고리즘이 적용된 field 모델에 비해 더 빠른 계산시간을 보여 주었다.

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간호원의 스트레스 관리교육 효과에 관한 실험연구 (An Experimental Study on the Effects of the Stress Management, Education Program for Nurses)

  • 안황란;구미옥;최미혜;정면숙
    • 대한간호학회지
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    • 제16권1호
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    • pp.40-48
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    • 1986
  • The purpose of this study was to identify the effect of the Stress Management Education Program (SMEP) on the nurses stress and stress management ability, and to identify the main factors affecting them. The subjects were 72 nurses who participated in the In-Service education program of the Jin-Ju District, Kyeong-Nam Branch of the Korean Nurses Association during the period from Oct. 1 to Nov. 30, 1985. The book of“The stress management education program”was developed by the investigators. With this book, we executed the 1st education through the lecture & showing an example, After 15 days from the 1st education, we mailed a reminding booklet to the individuals. (2nd education). Then, we mailed a questionnaire on 15th day from the 2nd education. Before and after the SMEP We measured the stress management ability & stress, and identified the affecting factors. Findings of this study are as follows ; 1. The 1st hypothesis that“the SMP will increase the. knowledge about the nurses' stress management”was supported (t= -6.60, p <.001) 2. The 2nd hypothesis that“the SMEP will increase the nurses' practice about the stress management”was rejected. 3. The 3rd hypothesis that“the SEMP will decrease the nurses' stress”was rejected. 4. The 4th hypothesis that“the higher the know-ledge about the stress management, the lower the nurses' stress”was rejected. 5. The 5th hypothesis that“the higher the degree of the practice about the stress management, the lower the nurses' stress”was supported. (r= - .2859, p<.05). 6. There were significant correlations between the knowledge about stress management and age (r= -.3717, p<.01), between the knowledge about stress management and the period of her work. (r= -.2897, p<0.5). There was significant difference in the knowledge about stress management between those who had married and those who had not. (t=2.82, p<.01) 7. There was significant difference in the practice about the stress management between those who had religion and those who had not. (t=2.7, p< .01) 8. There was significant difference in the stress according to the type or work. (t=6. 127, P <.05) There was significant correlation between the stress and supportive system. (r=-.2647, p<.05).

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밭작물의 뿌리성장과 생육시기별 토양수분 소비형태에 관한 연구 - 콩, 고추, 참깨 - (A Study on Root Growth and Soil Moisture Extraction Patten during Growing Period of Upland Crops -Soybean, Redpepper, Sesame-)

  • 정하우;박상현;김성준;정영신
    • 한국농공학회지
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    • 제35권1호
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    • pp.67-75
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    • 1993
  • This study is to analyze both root growth and soil moisture extraction pattern during the growing period of upland crops with respect to soybean, redpepper, sesame. Field and lysimeter tests were conducted under 12 treatments of soil moisture level by the San Cristobal experimental design(1981) and 3 soil type(sand, sandy loam, silty loam) for 4 years('87-'90) at the experimental plot of Rural Development Administration located in Suwon. The results of this study are summarized as follows : 1.For soybean, redpepper and sesame, root growth in dry soil was better than that in wet soil and it could be expressed as a sin function in terms of time. Maximum root depth was about 55cm, 44cm, 40cm respectively. 2.The average soil moisture extraction pattern for soybean, redpepper and sesame were 61.4%, 62.8%, 79.5% for zone l(0-l5cm). 25.5%, 27.1%, 18.3%, for zone 2(15-30cm).11.4%, 9.8%, 2.3% for zone 3(30-45cm), 1.7%, 0.3%, 0.04% for zone 4(45-60cm) respectively. This means that Zone 1 would be the dominant zone in irrigation scheduling. 3.With respect to soybean, the soil moisture extraction pattern(SMEP) was varied somewhat according to the erent maintenance of soil moisture level. The average SMEP for high maintenance of soil moisture was 46%, 29%, 17%, 8%, for middle maintenance of soil moisture was 43%, 29%, 17%, 11 % and for low maintenance of soil moisture was 40%, 28%, 20%, 12%, respectively. 4.With respect to soybean, the soil moisture in the upper layer was distinctly consumed more than that in the lower layer for clay loam soil and the soil moisture of all layers was consumed evenly for sand soil. The SMEP for sandy loam soil showed a middle result compared with the above 2 soil types.

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A Study on Smoke Movement in Room Fires with Various Pool Fire Location

  • Jeong, Jin-Yong;Ryou, Hong-Sun
    • Journal of Mechanical Science and Technology
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    • 제16권11호
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    • pp.1485-1496
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    • 2002
  • In order to investigate the fire-induced smoke movement in a three-dimensional room with an open door, numerical and experimental study was performed. The center, wall, and corner fire plumes for various sized fires were studied experimentally in a rectangular pool fire using methanol as a fuel. The numerical results from a self-developed SMEP (Smoke Movement Estimating Program) field model were compared with experimental results obtained in this and from literature. Comparisons of SMEP and experimental results have shown reasonable agreement. As the fire strength became larger for the center fires, the air mass flow rate in the door, average hot layer temperature, flame angle and mean flame height were observed to increase but the doorway-neutral-planeheight and the steady-state time were observed to decrease. Also as the wall effect became larger in room fires, the hot layer temperature, mean flame height, doorway-neutral-planeheight and steady-state time were observed to increase. In the egress point of view considering the smoke filling time and the early spread of plume in the room space, the results of the center fire appeared to be more dangerous as compared with the wall and the corner fire. Thus it is necessary to consider the wall effect as an important factor in designing efficient fire protection systems.

Weighing Lysimeter에 의한 결구상치의 증발산량 조사연구 (Study on the Evapotranspiration of Crisphead Lettuce by the Weighing Lysimeter)

  • 김시원;김선주;노희수
    • 한국농공학회지
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    • 제28권4호
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    • pp.41-48
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    • 1986
  • This study was fulfilled by the weighing lysimeter method at the experimental farm of KonKuk University from April to June of 1986 to investgate the amount of evapotranspiration ( ET-lettuec )by the growing periods, evapotranspiration ratio, amount of watering per one time, days of intermission and soil moisture extraction pattern of the crisphead lettuce cultivated in the clay loam soil by different watering points of pFl.7, pF2.O, pF2.7. The results obtained are summar ized as follows : 1.The total evapotranspiration(ETlettuce) of the pFl.7 treatment plot was 358,9mm., 314.9mm in the pF2.O plot and 281.8mm in the pF2.7 plot, therefore the total ETlettuec increased with the difference of 33mm-44mm by the decrease of watering point. 2.The daily maximum ETlettuce by the watering points was 7.66mm, 6:54mm, 5.98mm, respectively in the last ten days of May, and the mean daily ETlettuce during the growing season by the watering points of pFl.7, pF2.O and pF2.7 was 5.44mm(384.5g), 4.77mm(337.2g) and 4.27mm(301.8g), respectively. 3.The evapotranspiration ratio showed maximum value in the middle of May which was the beginning of mid-season stage, and the mean evapotranspiration ratio during the total growing period was 1A7, 1.29, 1.15 by the watering points. 4.The days of watering intermission by the watering points of pFl.7, pF2.O and pF2.7 was 1.0day, 2.9days and 12.Sdays, respectively. 5.The yield of the crisphead lettuce by the watering treatments showed very high significance, and the pF2.O was confirmed as a optimum watering point. 6.The soil moisture extraction pattern(SMEP) of the pF2.0 treatment plot in the initial stage was 85.6% in the 1st and 2nd soil layer and 14.4% in the 3rd and 4th layer, and in the midseason stage, the moisture extraction proportion of the under layer accounted for 34.7%which showed that the root elongated to the lowest soil layer, and there was no difference of the SMEP between the mid-season and late-season stage. 7.The correlation coefficient between the ETlettuce and yield of lettuce by the three watering points was.739, which showed the significance of 5%.

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