湍流频散对边界层风廓线的影响

摘要

New Reynolds mean momentum equations including turbulent viscosity and dispersion are used to ana-lyze the vertical profile of wind speed in the surface layer. It is demonstrated that the wind profile of the sur-face layer including turbulent dispersion has a logarithmic modification on the classical power law. Underthe condition of unstable stratification, the effect of dispersion is stronger than under stable stratification.Under neutral stratification, the power law degenerates to the logarithmic law, but the yon Karman con-stant is replaced by k1 =(l+k/4)-1k, which can also be obtained by similarity theory.%应用包括湍流粘性和频散的新的Reynolds平均动量方程,分析了边界层的垂直风速廓线,发现包含湍流频散的地面层的风速廓线对经典的风廓线指数规律有一个对数规律的修改;而且在不稳定层结下比在稳定层结下,湍流的频散效应更为显著;在中性条件下,指数规律退化为对数规律并且Karman常数被另外一个常数所代替,而这个新常数也可以通过相似理论来获得.