Turbulence measurements in stratified and well-mixed estuarine flows
Turbulence measurements in stratified and well-mixed estuarine flows
复制标题
DOI：
10.1016/0272-7714(83)90021-5
复制
发表时间：
1983-09
影响因子：
2.8
通讯作者：
H. Anwar
中科院分区：
文献类型：
--
作者：
H. Anwar
从河口流中测量的平均速度发现，分层流中的速度分布是对数线性的，而混合良好的流中则是对数分布的。盐度测量结果表明，平均盐度分布在几何上相似，并且可以用幂律表示。浮力参数，例如 Monin-Obukhov 长度尺度、梯度和通量理查森数，与流动状态无关。梯度和通量理查森数几乎相等，表明存在局部平衡层。对于分层流和充分混合流，描述湍流动能耗散率的无量纲参数分别为常数 0·2 和 0·3。在充分混合的流动中，当流动分层时，阻力系数随时间变化，接近大约 3·2 × 10−3 的常数。与充分混合流相比，分层湍流能谱的形状通常更平坦、更宽。
From mean velocities measured in estuarine flows it has been found that the velocity distributions are log-linear in stratified flows and logarithmic in well-mixed flows. The results of salinity measurements reveal that the mean salinity profiles are geometrically similar and expressible as a power law. The buoyancy parameters, such as the Monin-Obukhov length scale, the gradient and the flux Richardson numbers, are independent of the flow state. The gradient and the flux Richardson numbers are almost equal, indicating the existence of a local equilibrium layer. The non-dimensional parameter describing dissipation rates of turbulent kinetic energy is a constant of 0·2 and 0·3 for stratified and well-mixed flows respectively. In well-mixed flow the drag coefficient varies with time approaching a constant of about 3·2 × 10−3when the flow is stratified. The shape of the turbulent energy spectra are generally flatter and broader in stratified as compared with those of well-mixed flows.