인공 도로협곡 관측 자료를 활용한 전산유체역학모델 검증
Verification of Computational Fluid Dynamics Model Using Observation Data in Artificial Street Canyon
2
조회
0
다운로드
3
인용
0
참고문헌
키워드
초록
In this study, performance of a computational fluid dynamics (CFD) model is assessed from analysis on air flow pattern which is observed in the artificial street canyon. Field observations focusing on flows were conducted at an artificial street canyon in Magok region. For the observation of three-dimensional airflow structures, twelve three-dimensional wind anemometers (hereafter, CSAT3) were installed inside the street canyon. The street canyon was composed of two rectangular buildings with 35-m length, 4-m width, and 7-m height. The street width (distance between the buildings) is 7 m, making the street aspect ratio (defined by the ratio of building height to street width) of 1. For the observation of above-building wind, a CSAT3 was installed above the northwest-side building. Southwesterly, westerly and northwesterly were dominant in the street canyon during the observations. Because wind direction is parallel to the street canyon in the southwesterly case, westerly and northwesterly were selected as inflow directions in numerical simulations using a computational fluid dynamics model developed through the collaborative research project between National Institute of Meteorological Sciences and Seoul National University (CFD_NIMR_SNU). The observations showed that a well-structured vortex flow (skimming flow) and an evidence of a small eddy at the corner of the downwind building and ground appeared. The CFD_NIMR_SNU reproduced both the observed flow patterns reasonably well, although wind speeds inside the street canyon were underestimated.
Abstract
In this study, performance of a computational fluid dynamics (CFD) model is assessed from analysis on air flow pattern which is observed in the artificial street canyon. Field observations focusing on flows were conducted at an artificial street canyon in Magok region. For the observation of three-dimensional airflow structures, twelve three-dimensional wind anemometers (hereafter, CSAT3) were installed inside the street canyon. The street canyon was composed of two rectangular buildings with 35-m length, 4-m width, and 7-m height. The street width (distance between the buildings) is 7 m, making the street aspect ratio (defined by the ratio of building height to street width) of 1. For the observation of above-building wind, a CSAT3 was installed above the northwest-side building. Southwesterly, westerly and northwesterly were dominant in the street canyon during the observations. Because wind direction is parallel to the street canyon in the southwesterly case, westerly and northwesterly were selected as inflow directions in numerical simulations using a computational fluid dynamics model developed through the collaborative research project between National Institute of Meteorological Sciences and Seoul National University (CFD_NIMR_SNU). The observations showed that a well-structured vortex flow (skimming flow) and an evidence of a small eddy at the corner of the downwind building and ground appeared. The CFD_NIMR_SNU reproduced both the observed flow patterns reasonably well, although wind speeds inside the street canyon were underestimated.
참고문헌 (30)
- Baik, J. -J., "A numerical study of flow and pollutant dispersion characteristics in urban street canyons", J. Appl. Meteor, 38, pp.1576~1589 (1999)
- Baik, J. -J., "A CFD model for simulating urban flow and dispersion", J. Appl. Meteor, 42, pp.1636~1648 (2003)
- Baik, J. -J., "A laboratory model of urban street-canyon flows", J. Appl. Meteor, 39, pp.1592~1600 (2000)
- Brown, M. J., "Mean flow and turbulence measurements around a 2-D array of buildings in a wind tunnel", 11th Joint Conf. on the Applications of Air Pollution Meteorology with the A&WMA, pp.35~40 (2000)
- Cheng, X., "Numerical studies on flow fields around buildings in an urban street canyon and cross-road", Adv. Atmos. Sci, 22, pp.290~299 (2005)
- Cheng, Y., "A comparison of large eddy simulations with a standard k-ε Reynolds-averaged Navier-Stokes model for the prediction of a fully developed turbulent flow over a matrix of cubes", J. Wind Eng. Ind. Aerod, 91, pp.1301~1328 (2003)
- DePaul, F. T., "A tracer study of dispersion in an urban street canyon", Atmos. Environ, 19, pp.555~559 (1985)
- Eliasson I., "Wind fields and turbulence statistics in an urban street canyon", Atmos. Environ, 40, pp.1~16 (2006)
- Idzak, M., "Micrometeorological measurement in a street canyon during, the joint ATREUS_PICADA experiment", Bound.-Lay. Meteorol, 124, pp.25~41 (2007)
- 김재진, "장애물 외관비가 주변 흐름에 미치는 영향", 대기, 17(4) (2007), 한국기상학회
- Kim, J. J., "A numerical study of the effects of ambient wind direction on flow and dispersion in urban street canyons using the RNG k-ε turbulence model", Atmos. Environ, 40, pp.5640~5658 (2004)
- 김재진, "CFD 모형을 이용한 도시지역 흐름 및 스칼라 분산연구", 한국기상학회지, 41(5), pp.733~749 (2005), 한국기상학회
- Kim, J. J., "Physical experiments to investigate the effects of street bottom heating and inflow turbulence on urban street-canyon flow", Adv. Atmos. Sci, 22, pp.230~237 (2005)
- 이영수, "도시 지역에서 아파트 단지가 흐름과 확산에 미치는 영향", 대기, 21(2), pp.95~108 (2011), 한국기상학회
- Neophytou, M. K., "Modeling the wind flow in complex urban topographies: A computational- fluid dynamics simulation of the central London area", Proc. 5th GRACM International Congress on Computational Mechanics Limassol, 29 (2005)
- Li, X. X., "Recent progress in CFD modeling of wind field and pollutant transport in street canyons", Atmos. Environ, 40, pp.5640~5658 (2009)
- Liu, C. -H., "Large-eddy simulation of flow and scalar transport in a modeled street can yon", J. Appl. Meteor, 41, pp.660~673 (2002)
- Liu, H. Z., "A laboratory model for the flow in urban street canyons induced by bottom heating", Adv. Atmos. Sci., 20, pp.554~564 (2003)
- Meroney, R. N., "Study of line source characteristics for 2-D physical modelling of pollutant dispersion in street canyon", J. Wind Eng. Ind. Aerod, 62, pp.37~56 (1996)
- Milliez, M., "Numerical simulations of pollutant dispersion in an idealized urban area, for different meteorological conditions", Bound.- Lay. Meteorol, 122, pp.321~342 (2007)
- Nakamura, Y., "Wind, temperature, and stability conditions in an east-west oriented urban canyon", Atmos. Environ, 22, pp.2691~2700 (1988)
- 박승부, "CFD 모형을 이용한 3차원 비대칭 도로 협곡에서의흐름 및 오염물질 분산 연구", 한국대기환경학회지, 23(2), pp.214~224 (2007), 한국대기환경학회
- Patankar, S. V., "Numerical Heat Transfer and Fluid flow", pp.197~ (1980), McGraw-Hill
- Rotach, M. W., "Profiles of turbulence statistics in and above an urban street canyon", Atmos. Environ, 29, pp.1473~1486 (1995)
- Santiago, J. L., "CFD simulation of airflow over a regular array of cubes. Part I: Three-dimensional simulation of the flow and validation with wind-tunnel measurements", Bound.-Lay. Meteorol, 122, pp.609~634 (2007)
- Sini, J. -F., "Pollutant dispersion and thermal effects in urban street canyons", Atmos. Environ, 30, pp.2659~2677 (1996)
- Tutar, M., "Large eddy simulation of wind flow around parallel buildings with varying configurations", Fluid Dyn., Res, 31, pp.289~315 (2002)
- Uehara, K., "Wind tunnel experiments on how thermal stratification affects flow in and above urban street canyons", Atmos. Environ, 34, pp.1553~1562 (2000)
- Yakhot, V., "Development of turbulence models for shear flows by a double expansion technique", Phys. Fluids A, 4, pp.1510~1520 (1992)
- Yakhot, A., "Direct numerical simulation of turbulent flow around a wallmounted cube: spatio-temporal evolution of largescale vortices", J. Fluid Mech, 566, pp.1~9 (2006)