南京雾—霾天气个例湍流运动特征的对比研究

发布时间：2018-06-17 12:17

本文选题：雾 + 霾　；参考：《南京信息工程大学》2015年硕士论文

【摘要】：本文利用超声风速仪、能见度仪等资料,对比了南京郊区2013年12月4日一次霾过程、2013年12月7—-9日一次雾过程和2013年12月3日一个晴天的湍流运动特征,分析了雾、霾、晴天的生消发展过程,研究了边界层内的温度场和湿度场,并对其湍流参量的演变特征、统计特征和谱分析特征进行了分析,最后分析研究了湍流对雾、霾天气的影响。研究结果表明：霾天和晴天平均水平风速、平均动能、湍流动能、湍强、摩擦速度、动量通量和热量通量都有明显的日变化,而这些参量在雾天没有明显的日变化,不同天气湍流参量大小有差异；霾、雾、晴天近中性层结下u、v、w三个方向风速归一化标准差近似为常数,霾天分别为3.15、2.72和1.17,雾天分别为3.11、2.45和1.25,晴天分别为3.40、3.45和1.50；不稳定条件下霾、雾、晴天风速归一化标准差和湍流动能归一化标准差符合1/3幂次律,稳定条件下霾、雾、晴天无因次湍流动能均满足1/3幂次律,不稳定条件下霾、雾、晴天温度和湿度归一化标准差满足-1/3幂次律,稳定条件下霾、雾、晴天温度归一化标准差符合-2/3幂次律。雾天归一化u、v、w谱与Kansas谱吻合度比霾天和晴天高,霾天u、v、w谱峰值频率约为0.01Hz,雾天“谱峰值频率约为0.004Hz, v、w谱峰值频率约为O.1Hz,晴天“、v、w谱峰值频率约为0.01Hz。霾天和晴天以机械湍流为主,雾天既有机械湍流也有热力湍流。雾发展越强,数浓度和液水含量(N,lwc)起伏越大,起伏强度反而越小,雾滴数浓度随着湍强增大而增大。霾天平均半径r的起伏大小随平均半径递增,数浓度N的起伏大小随N递增。平均半径和平均半径的起伏强度(r,4)随三维方向湍强Iu,v,2递减,平均半径的起伏大小σr随Itt递减,平均半径的起伏大小σr随Iv,w,先增大后减小。数浓度和数浓度的起伏大小(N,σN)随Iu,v,w递增。
[Abstract]:Based on the data of ultrasonic anemometer and visibility meter, this paper compares the characteristics of haze on December 4, 2013, smog from December 7 to 9, and turbulent motion on a sunny day on December 3, 2013 in the suburbs of Nanjing, and analyzes the characteristics of fog and haze. In this paper, the temperature and humidity fields in the boundary layer are studied, and the evolution, statistical and spectral characteristics of the turbulent parameters are analyzed. Finally, the influence of turbulence on the fog and haze weather is analyzed. The results show that the average horizontal wind speed, mean kinetic energy, turbulent intensity, friction velocity, momentum flux and heat flux have obvious diurnal variations in smog and sunny days. The normalized standard deviation of wind speed in the three directions of smog, fog and clear neuter layer is approximately constant, the mean values of wind speed are 3.152.72 and 1.17 in haze days, 3.11 ~ 2.45 and 1.25 in smog days, and 3.40 ~ 3.45 and 1.50 in fine days, respectively. Under unstable conditions, the normalized standard deviation of wind speed and the normalized standard deviation of turbulent kinetic energy conform to the 1 / 3 power law. Under stable conditions, smog, fog, and sunny day turbulent kinetic energy all satisfy 1 / 3 power law. Under unstable conditions, haze, fog, The normalized standard deviations of temperature and humidity in sunny days satisfy the -1 / 3 power law, and the normalized standard deviations of haze, fog and clear weather temperature conform to the -2 / 3 power law under stable conditions. The results show that the peak frequency of the normalized UVW spectrum is higher than that of the smog day and the Kansas spectrum, the peak frequency of the fog day is about 0.01 Hz, the peak frequency of the fog "spectrum is about 0.004 Hz, the peak frequency of the VW spectrum is about 0.1 Hz, and the peak frequency of the VW spectrum is about 0.01 Hz in the sunny day. Haze and sunny days are dominated by mechanical turbulence, and there is both mechanical and thermal turbulence in foggy days. The stronger the fog develops, the greater the fluctuation of number concentration and liquid water content is, the smaller the fluctuation intensity is, and the more the concentration of droplet number increases with the increase of turbulent intensity. The mean radius r of haze increased with the mean radius, and the fluctuation of number concentration N increased with N. The fluctuation intensity of mean radius and mean radius decreases with the three dimensional turbulence intensity, the fluctuation size 蟽 r of the mean radius decreases with ITT, and the fluctuation magnitude 蟽 r of the mean radius increases first and then decreases. The fluctuation of number concentration and number concentration N, 蟽 N) increases with the increase of iuv / w.
【学位授予单位】：南京信息工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X513;P426.4

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