邊界入流風場擾動對模擬城市大氣擴散的影響
發(fā)布時間:2018-02-12 07:02
本文關鍵詞: 城市擴散 中性層結 CFD 邊界條件 數(shù)值試驗 出處:《中國環(huán)境科學》2017年09期 論文類型:期刊論文
【摘要】:借助計算流體動力學(CFD)模式Fluent分析中性層結下邊界入流風場(即風速和風向)擾動對地面點源釋放情景下城市大氣擴散過程的影響,其中邊界入流條件以風速和湍流動能廓線的形式給出.研究發(fā)現(xiàn)CFD模式能夠合理刻畫實際城市中的特征流型(如渦旋,峽谷效應等),而且模擬的風速、風向和湍流動能均與觀測數(shù)據(jù)吻合較好.敏感性試驗結果表明,城區(qū)內(nèi)的流場和湍流以及與之密切相關的污染物空間分布對邊界入流風速和風向的擾動十分敏感.而這可能是造成已有研究中濃度模擬值與觀測值不一致的主要原因之一.因此,在模擬城市大氣擴散過程時應當考慮邊界入流風場不確定性對模擬結果的影響.
[Abstract]:By using the computational fluid dynamics (CFD) model Fluent, the influence of the disturbance of the boundary inlet wind field (I. E. wind speed and wind direction) on the urban atmospheric diffusion process under the ground point source release scenario is analyzed. The boundary flow conditions are given in the form of wind speed and turbulent kinetic energy profile. It is found that the CFD model can reasonably describe the characteristic flow patterns (such as vortex, canyon effect, etc.) in the actual city, and the simulated wind speed. The wind direction and turbulent kinetic energy are in good agreement with the observed data. The flow field and turbulence in urban area and the spatial distribution of pollutants closely related to them are very sensitive to the disturbance of the wind speed and direction of the boundary flow, which may be the main cause of the inconsistency between the simulated and observed concentration values in previous studies. One of the reasons. The influence of boundary inlet wind field uncertainty on the simulation results should be considered in the simulation of urban atmospheric diffusion process.
【作者單位】: 蘭州大學大氣科學學院半干旱氣候變化教育部重點實驗室;中國科學院西北生態(tài)環(huán)境資源研究院寒旱區(qū)陸面過程與氣候變化重點實驗室;中國人民解放軍93811部隊;
【基金】:國家“973”計劃項目(2011CB706903) 國家自然科學基金資助項目(41275019,41475009)
【分類號】:X169
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本文編號:1505051
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