引用本文: | 高昂,吴修锋,吴时强,戴江玉,王芳芳,吴晨晖.有限水域近水面气流演化特征试验研究.湖泊科学,2022,34(3):994-1005. DOI:10.18307/2022.0323 |
| Gao Ang,Wu Xiufeng,Wu Shiqiang,Dai Jiangyu,Wang Fangfang,Wu Chenhui.Experimental study on the evolution characteristics of near-surface airflow in limited waters. J. Lake Sci.2022,34(3):994-1005. DOI:10.18307/2022.0323 |
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有限水域近水面气流演化特征试验研究 |
高昂1,2, 吴修锋1,2, 吴时强1,2, 戴江玉1,2, 王芳芳1,2, 吴晨晖1,2
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1.南京水利科学研究院, 水文水资源与水利工程科学国家重点实验室, 南京 210029;2.水利部太湖流域水治理重点实验室, 南京 210029
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摘要: |
气流作为湖泊、湿地等有限水域的主要驱动力之一,其演化特征是研究水-气间能量与物质传递的基础,决定了水域水环境与水生态格局,具有重要研究意义.采用室内风洞水槽,通过设置不同试验风速,研究近水面气流与风速和吹程的响应关系与演化特征,并将光滑壁面条件下的气流特征作为试验对照组,分析时间域内风速垂向分布形式、摩阻风速、特征粗糙度等变化规律,剖析频率域内风速的主频变化与波致气流边界层厚度等参数的分布特征.结果表明:近水面时均风速符合对数分布,摩阻风速与特征粗糙度均与风速呈正相关,且同等风速与吹程条件下两者均大于光滑壁面条件,波致气流边界层厚度与风速和吹程均呈正相关.分析了采用风速作为气流动力参数存在不妥的原因,认为采用摩阻风速或切应力作为气流动力参数更具合理性,基于前人研究数据的统计分析,给出了特征粗糙度与风速、吹程和水深的回归关系式.探讨了气流-风浪“同频率”的互馈模式,发现波致气流边界层厚度不只与波长有关,还受波高、波周期和水深等多因素影响,建立了考虑风浪非线性特征的波致气流边界层厚度关系式. |
关键词: 有限水域|演化特征|特征粗糙度|气流边界层|互馈模式 |
DOI:10.18307/2022.0323 |
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基金项目:国家重点研发计划项目(2018YFC0407200)、国家自然科学基金项目(51909169)、江苏省基础研究计划(自然科学基金)项目(SBK2019042181)和中央级公益性科研院所基本科研业务费专项资金项目(Y121006,Y120010)联合资助. |
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Experimental study on the evolution characteristics of near-surface airflow in limited waters |
Gao Ang,Wu Xiufeng,Wu Shiqiang,Dai Jiangyu,Wang Fangfang,Wu Chenhui
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Key Laboratory of Taihu Basin Water Management, Ministry of Water Resources, Nanjing 210029, P. R. China
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Abstract: |
As one of the main driving forces of limited water areas such as lakes and wetlands, the evolution characteristics of airflow are the basis for the study of water-air energy and material transfer, which determines the water environment as well as water ecological pattern of water area, and has important research significance. Using wind tunnel flume, by setting different wind speeds, the response relationship and evolution law of near-surface airflow with wind speed and blowing distance were studied, particularly, flow characteristics under the condition of smooth wall were taken as the test control group, vertical distributions of wind speed, friction wind speed, roughness and so on were analyzed in time domain, and domain frequency change of wind speed and boundary layer thickness of wave-induced airflow are analyzed in the frequency. Results show that the average wind speed near the water surface conforms to the logarithmic distribution, the friction wind speed and characteristic roughness are all positively correlated with the wind speed, and both of them are greater than the smooth wall condition under the same wind speed and blowing distance, and the wave-induced airflow boundary layer thickness is positively correlated with the wind speed and blowing distance. The reasons for the improper use of wind speed as the aerodynamic dynamic parameter are analyzed, and it is considered that it is more reasonable to use friction wind speed or shear stress as the aerodynamic dynamic parameter, and the regression relationship between characteristic roughness and wind speed, blowing distance and water depth is given. The mutual feed model of airflow and wind wave with "same frequency" is discussed, it is found that the thickness of the wave-induced airflow boundary layer is not only related to the wavelength, but also affected by wave height, wave period and water depth, and the relation formula of the wave-induced airflow boundary thickness considering the nonlinear characteristics of wind and wave is established. |
Key words: Limited waters|evolution characteristics|characteristic roughness|airflow boundary layer|mutual feed model |
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