珠江河口底边界层湍流特征量研究  

Research on turbulent features of the bottom boundary layer in the Pearl River

作　　者：刘欢[1,2] 吴超羽[2] 许炜铭[1] 杨日魁[2] 

机构地区：[1]中山大学工学院力学系,广东广州510275 [2]中山大学近岸海洋研究中心,广东广州510275

出　　处：《海洋工程》2009年第1期62-69,76,共9页The Ocean Engineering

基　　金：国家自然科学基金资助项目(40176026;40331007;40676056;10772204);"973"资助项目(2002CB412407)

摘　　要：通过高频流速仪ADV和脉冲相干声学多普勒剖面仪PC-ADP对珠江河口崖门底边界层进行了三个测次潮内(25 h)顶点连续观测,利用观测数据计算分析了潮流底边界层内的湍流特征量及其时空变化。结果表明:1)对于半日潮流占优的河口,各湍流特征量均具有明显的四分之一周日的变化规律;2)湍流强度、床底应力和摩阻流速在潮内的平均值以位于河口湾的测点所测值最大,依次向上游递减,而湍动能耗散率则沿河口湾至上游逐渐增大;3)三个测次边界层内涡动粘滞系数的平均值分别为2.42×10-3m2/s、2.20×10-4m2/s和6.16×10-4m2/s,拖曳系数的均值为7.89×10-3、1.63×10-3和1.99×10-2,两者潮内的变化均非常显著,相差可达一到两个数量级;4)在充分混合的潮流底边界层内,湍动能生成与耗散基本处于局部平衡状态,三个测次湍动能耗散率均值在8.89×10-5W/kg^7.43×10-6W/kg之间。The temporal and spatial changes of turbulent features within the tidally-induced bottom boundary layer at Yamen the in the Pearl River are discussed based on the synchronously surveyed data over 25 hours in three stations by using ADV and PC-ADP. The result shows that： （1） Turbulence features have evident demisemi daily change in semidiurnal estuary; （2） Turbulence intensity, bottom stress and friction velocity decrease from firth to upriver, but turbulent kinetic energy（TKE） dissipation rate is opposite; （3） Mean eddy viscosity in three stations is 2.42×10^- 3 m^2/s, 2.20 × 10^-4 m^2/s and 6.16×10^-4m^2/s, and mean drag coefficient is 7.89 × 10^- 3,1.63 × 10^- 3 and 1.99×10^-2 respectively. Both of them change by 1 - 2 magnitudes in a tidal cycle; （4） TKE generation and dissipation are balanced in well mixed tidally- induced bottom boundary layer with mean dissipation rating ranging from 8.89 × 10^-5 W/kg-7.43 × 10^-6 W/kg in three stations.

关 键 词：底边界层 湍流特征量 ADV 珠江河口 

分 类 号：O357.4[理学—流体力学]