珠江河口潮流底边界层的湍流特征量研究

Turbulence feature research within bottom boundary layer induced by tide in the Pearl River Estuary

通过高频流速仪ADV和声学Doppler剖面仪ADP对珠江河口虎门潮流底边界层进行了一个周日(25h)定点连续观测,利用观测数据计算分析了洪季潮优型河口潮流底边界层内的湍流特征量。结果表明,(1)底边界层内的湍流具有一定的各向异性,脉动分量概率分布为准正态分布;(2)对于半日潮流占优的河口,湍流脉动强度、底床切应力、摩阻流速以及湍动能耗散率等均具有明显的四分之一周日的变化规律;(3)边界层内床底切应力与摩阻流速的变化范围分别为1.8×10-2～3.5×10-1Nm-2和2.2×10-3～1.8×10-2ms-1,湍动能耗散率平均值约为1.9×10-5Wkg-1。

The turbulent features within bottom boundary layer flow induced by tide at Humen in flood season was discussed based on the synchronously survey data over 25 hours using ADV and ADE The results showed that： （1） Turbulence within bottom boundary layer（BBL） is anisotropy, turbulent flow components have quasi-normal probability distributions; （2） Turbulence intensity, bottom stress, friction velocity and turbulent kinetic energy（TKE） dissipation rate have evident demisemi daily change in semidiurnal tide estuary; （3） Bottom stress and friction velocity range from 1.8×10^-2～3.5×10^-1Nm^2 and2.2×10^-3～1.8×10^-2ms^-1respectively, mean TKE dissipation is 1.9×10^-5Wkg^-1 in BBL.