Critical flux Richardson number for Kolmogorov turbulence enabled by TKE transport
Critical flux Richardson number for Kolmogorov turbulence enabled by TKE transport
复制标题
DOI：
10.1002/qj.3511
复制
发表时间：
2019-04-01
影响因子：
8.9
通讯作者：
Dias, Nelson L.
中科院分区：
文献类型：
--
作者：
Freire, Livia S.;Chamecki, Marcelo;Dias, Nelson L.
在稳定分层流中，通量理查森数Ri（f）是浮力破坏和湍流动能（TKE）的剪切产生之间的比率的量度。在剪切产生、浮力破坏和TKE耗散之间具有局部平衡的流动中，临界Ri（f，c）约为0.21，对应于Kolmogorov湍流不再持续的极限。TKE和速度方差收支方程的分析表明，TKE的正湍流输送的存在下，临界Ri（f，c）增加。这种情况是观察到的，例如，在粗糙子层以上的植物冠层，证明使用现场数据从亚马逊雨林。
In stably stratified flows, the flux Richardson number Ri(f) is a measure of the ratio between buoyancy destruction and shear production of turbulent kinetic energy (TKE). In flows with local equilibrium between shear production, buoyancy destruction and dissipation of TKE, the critical Ri(f,c)approximate to 0.21 corresponds to the limit above which Kolmogorov turbulence can no longer be sustained. Analysis of the TKE and velocity variance budget equations shows that the critical Ri(f,c) is increased by the presence of positive turbulent transport of TKE. This situation is observed, for example, in the roughness sublayer above plant canopies, as demonstrated using field data from the Amazon rainforest.