• Title/Summary/Keyword: complex terrain

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Wind Tunnel Experiments for Studying Atmospheric Dispersion in the Complex Terrain II. Gaussian Modeling of Experiments in a Moutainous Area (복잡한 지형내 오염물질의 대기확산 풍동실험 I I. 산지지형 실험의 Gaussian 모델링)

  • 김영성;경남호
    • Journal of Korean Society for Atmospheric Environment
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    • v.11 no.2
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    • pp.145-152
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    • 1995
  • Predictability of a Gaussian model, ISCST2 was assessed by scaling up wind tunnel experiments with a 1/3,000 terrain model to the real scale. Concentration profiles obtained from the flat-terrain experiment in the neutral condition were estimated to be in agreement with the calculated ones from ISCST2 in the stability class A, but the difference between the two was still large. Concentration profiles from the mountainous-terrain experiments were better fitted to the calculated ones primarily because in the experiment, concentration behind the source was raised due to the effect of a hill in the upstream side. Model prediction was improved with including the downwash effect of buildings and the hill, but overall concentration profiles were not much different from a typical Gaussian profile. While concentration profiles in the experiments were changed with local flows by varying the wind direction and the topography, those from the Gaussian modeling were mot freely changed together with these variations.

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Experimental investigation of wind flow characteristics over hills and escarpments - A review

  • Wani, Abdul Haseeb;Varma, Rajendra K.;Ahuja, Ashok K.
    • Wind and Structures
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    • v.32 no.4
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    • pp.393-403
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    • 2021
  • A comprehensive knowledge of the wind flow in hilly terrains is of great interest in many engineering applications, be it wind energy distribution for suitable site selection for wind farms, pollution dispersion, forest fire propagation or agrometerological studies. Several researchers have shown that wind flow over a hilly terrain may be significantly different when compared with the wind flow over a flat terrain. Complex hilly terrains may alter the wind speed to a great extent. Therefore, this effect of terrain must be properly assessed by designers and planners to arrive at a proper wind flow distribution. This paper reviews the work done in this area over the past three decades. Wind flow over two-dimensional hills and two-dimensional escarpments investigated in wind tunnels by various researchers is presented in this paper.

A Numerical Study on the Effect of Mountainous Terrain and Turbine Arrangement on the Performance of Wind Power Generation (지형에 따른 발전기 배치가 풍력 발전 성능에 미치는 영향에 관한 수치해석 연구)

  • Lee, Myung-Sung;Lee, Seung-Ho;Hur, Nahm-Keon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.10
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    • pp.901-906
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    • 2010
  • A three-dimensional flow simulation was performed to investigate the flow field in a wind farm on a complex terrain. The present study aims to examine the effects of mountainous terrain and turbine arrangement on the performance of wind power generation. A total of 49 wind turbines was modeled in the computational domain; detailed blade shape of the turbines was considered. Frozen rotor method was used to simulate the rotating operation. The torque acting on the turbine blades was calculated to evaluate the performance of the wind turbines. The numerical results showed details of the flow structure in the wind farm including the velocity deficit in the separated flow regions; this velocity deficit was due to the topographical effect. The effect of the wake induced by the upstream turbine on the performance of the downstream wind turbine could also be observed from the results. The methodology of the present study can be used for selecting future wind-farm sites and wind-turbine locations in a selected site to ensure maximum power generation.

Comparative Analysis of the CALPUFF and AERMOD Atmospheric Dispersion Models for Ready-Mixed Concrete Manufacturing Facilities Generating Particulate Matter (미세먼지 발생 레미콘시설에서의 대기확산모델 CALPUFF와 AERMOD 비교 분석)

  • Han, Jin-hee;Kim, Younghee
    • Journal of Environmental Health Sciences
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    • v.47 no.3
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    • pp.267-278
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    • 2021
  • Objectives: Using atmospheric dispersion representative models (AERMOD and CALPUFF), the emissions characteristics of each model were compared and analyzed in ready-mixed concrete manufacturing facilities that generate a large amount of particulate matter (PM-10, PM-2.5). Methods: The target facilities were the ready-mixed concrete manufacturing facilities (Siheung RMC, Goyang RMC, Ganggin RMC) and modeling for each facility was performed by dividing it into construction and operation times. The predicted points for each target facility were selected as 8-12ea (Siheung RMC 10, Goyang RMC 8, and Gangjin RMC 12ea) based on an area within a two-kilometer radius of each project district. The terrain input data was SRTM-3 (January-December 2019). The meteorological input data was divided into surface weather and upper layer weather data, and weather data near the same facility as the target facility was used. The predicted results were presented as a 24-hour average concentration and an annual average concentration. Results: First, overall, CALPUFF showed a tendency to predict higher concentrations than AERMOD. Second, there was almost no difference in the concentration between the two models in non-complex terrain such as in mountainous areas, but in complex terrain, CALPUFF predicted higher concentrations than AERMOD. This is believed to be because CALPUFF better reflected topographic characteristics. Third, both CALPUFF and AERMOD predicted lower concentrations during operation (85.2-99.7%) than during construction, and annual average concentrations (76.4-99.9%) lower than those at 24 hours. Fourth, in the ready-mixed concrete manufacturing facility, PM-10 concentration (about 40 ㎍/m3) was predicted to be higher than PM-2.5 (about 24 ㎍/m3). Conclusions: In complex terrain such as mountainous areas, CALPUFF predicted higher concentrations than AERMOD, which is thought to be because CALPUFF better reflected topographic characteristics. In the future, it is recommended that CALPUFF be used in complex terrain and AERMOD be used in other areas to save modeling time. In a ready-mixed concrete facility, PM-10, which has a relatively large particle size, is generated more than PM-2.5 due to the raw materials used and manufacturing characteristics.

A Study on the Pollutant Dispersion over a Mountain Valley Region (I) : Wind Tunnel Experiments (산악 계곡지형에서의 오염확산에 관한 연구(I) :풍동실험)

  • Yoo Seong-Yeon;Shim Woo-Sup;Kim Seogcheol
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.11
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    • pp.1050-1059
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    • 2005
  • Heat and $SF_6$ gas dispersions over a complex terrain were investigated using wind tunnel. The wind speed, temperature and concentration profiles were measured for the 1/1000 scale complicated terrain model in an Eiffel type boundary layer wind tunnel with test section of 2.5m in height and 4.5m in width. The scale model was mounted on the top of a plate which can rotate with respect to the approaching wind. Dispersion processes from a continuous emission source driven by various wind direction were investigated, including plume climbing over the steep up-slope of the mountain and down-spreading toward the lower level of the valley. Extensive dispersion experiment data (wind speeds and concentration profiles) were provided for verification and validation of dispersion models. Under the identical flow and emission conditions, the independently measured profiles of the temperature and $SF_6$ concentration showed an excellent agreement which ensured the credibility of the results.

Study of evaluation wind resource detailed area with complex terrain using combined MM5/CALMET system (고해상도 바람지도 구축 시스템에 관한 연구)

  • Lee, Hwa-Woon;Kim, Dong-Hyeuk;Kim, Min-Jung;Lee, Soon-Hwan;Park, Soon-Young;Kim, Hyun-Goo
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.10a
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    • pp.274-277
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    • 2008
  • To evaluate high-resolution wind resources for local and coastal area with complex terrain was attemped to combine the prognostic MM5 mesoscale model with CALMET diagnostic modeling this study. Firstly, MM5 was simulated for 1km resolution, nested fine domain, with FDDA using QuikSCAT seawinds data was employed to improve initial meteorological fields. Wind field and other meteorological variables from MM5 with all vertical levels used as initial guess field for CALMET. And 5 surface and 1 radio sonde observation data is performed objective analysis whole domain cells. Initial and boundary condition are given by 3 hourly RDAPS data of KMA in prognostic MM5 simulation. Geophysical data was used high-resolution terrain elevation and land cover(30 seconds) data from USGS with MM5 simulation. On the other hand SRTM 90m resolution and EGIS 30m landuse was adopted for CALMET diagnostic simulation. The simulation was performed on whole year for 2007. Vertical wind field a hour from CALMET and latest results of MM5 simulation was comparison with wind profiler(KEOP-2007 campaign) data at HAENAM site.

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