• Title/Summary/Keyword: SMEP

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

  • 정진용;유홍선;김성찬;김충익
    • Fire Science and Engineering
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    • v.13 no.4
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    • pp.20-29
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    • 1999
  • This paper describes the smoke filling process of a fire field model based on a self-developed 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- epsilon turbulence model with buoyancy term. Compressibility is assumed and the perfect gas law is used. The results of the calculated upper-layer average temperature and smoke layer interface height has shown reasonable agreement compared with the zone models. The zone models used are the CFAST developed at the Building and Fire Research Laboratory NIST U.S.A. and the NBTC one-room of FIRECALC developed at CSIRO, Australia. The smoke layer interface heights that are important in fire safety were not as sensitive as the smoke layer temperature to the nature of ceiling heat flux condition.

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

  • 정진용;유홍선;홍기배
    • Fire Science and Engineering
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    • v.14 no.3
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    • pp.6-12
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    • 2000
  • This paper describes the smoke movement of a fire field model based on a self-developed SMEP(Smoke Movement Estimating Program) code to the simulation of fire induced flows in the two types of compartment space containing the radiation effect under smoke movement in room fire. 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 discrete ordinates method. The result of the calculated smoke temperature containing radiation effect has shown reasonable agreement compared with the experimental data. On the other hand, a difference of a lot was found between the temperature predicted by the SMEP with only convection effect and obtained by the experimental result. This seems to come from the radiation effect of $H_2$O and $CO_2$ gas under smoke productions. Thus, the consideration of the radiation effect under smoke in fire may be necessary in order to produce more realistic result.

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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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    • v.10 no.3
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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.

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

  • 정진용;유홍선;홍기배
    • Fire Science and Engineering
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    • v.15 no.1
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    • pp.7-15
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    • 2001
  • This paper describes the smoke filling process of a fire field model based on a self-developed SMEP (Smoke Movement Estimating Program) codo to the simulation of fire induced flows in the atrium space (SIVANS atrium at Japan) containing smoke radiation effect. 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 discrete ordinates method. The result of the calculated smoke temperature containing radiation effect has shown a better prediction than the result calculated by only convection effect in comparison with the experimental data. This seems to come from the radiation effect of $H_2$O and $CO_2$ gas under smoke productions. Thus, the consideration of the radiation effect under smoke in fire should be necessary in order to get more realistic result. Also the numerical results indicated that the smoke layer is developing at a rate of about 0.1 m/s. It would take about 450 seconds after starting the ultra fast fire of 560 kW that the smoke layer move down to 1.5m above the escape level.

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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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    • v.10 no.3
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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.

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

  • 정진용;유홍선;김성찬
    • Fire Science and Engineering
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    • v.13 no.1
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    • pp.21-30
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    • 1999
  • In this paper, the smoke filling process for the three types of atrium spaces are simulated u using the two types of deterministic fire model; zone models and field models. The zone models u used are the FffiST, CFAST, and CCFM.VENTS m떠els develo야퍼 at the Building and Fire R Research Laboratories, NIST, USA and the NBTC one-room model of FIR.ECAIι delveloped at C CSffiO, Austr;외ia. The field models used are the fire field model developed by W. K Chow and a a self-developed Sl\1EP(Smoke Movement Estimating Program) based on computational fluid d dynamics the$\alpha$1es. The results pn려icted by the two approaches are very similar. The field model u using SIl\1PLE algorithm or SIl\1PLER algorithm requires much more computing time compared w with the use of Sl\1EP using PISO algorithm.

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

  • 안황란;구미옥;최미혜;정면숙
    • Journal of Korean Academy of Nursing
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    • v.16 no.1
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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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A Study on Root Growth and Soil Moisture Extraction Patten during Growing Period of Upland Crops -Soybean, Redpepper, Sesame- (밭작물의 뿌리성장과 생육시기별 토양수분 소비형태에 관한 연구 - 콩, 고추, 참깨 -)

  • 정하우;박상현;김성준;정영신
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.35 no.1
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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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    • v.16 no.11
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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.

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

  • 김시원;김선주;노희수
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.28 no.4
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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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