论文标题
在三维立方阵列上的湍流施密特数量测量
Turbulent Schmidt Number Measurements Over Three-Dimensional Cubic Arrays
论文作者
论文摘要
我们在三维城市顶峰上方提出了湍流的schmidt sc_t估计，其中SC_T是该流量的特性，定义为动量（K_M）与质量的涡流扩散率的比率（D_T）。尽管对于通过计算流体动力学进行的污染物分散模拟，尽管SC_T建模引起了极大的兴趣，但众所周知。流体速度和质量浓度的同时测量在水通道中进行了三个交错的立方障碍物，对应于孤立的流动，唤醒和掠过流动方案。一个被动示踪剂是从位于高度z = 1.67h的连续点源释放的，其中H是障碍物高度。结果表明，与在z = h时相比，所有三个阵列的SC_T的增加，所有三个阵列的高度都高于冠层的高度，z = 2H（sc_t = 0.6）的值约为两倍。观察到的SC_T与基于先前研究中发表的K_M和D_T的表达式使用SC_T的简单公式建模的SC_T非常吻合。还提出和讨论了与文献中发现的其他SC_T模型的比较。
We present turbulent Schmidt number Sc_t estimations above three-dimensional urban canopies, where Sc_t is a property of the flow defined as the ratio of the eddy diffusivity of momentum (K_M) to the eddy diffusivity of mass (D_t). Despite the fact that Sc_t modelling is of great interest, inter alia, for pollutant dispersion simulations conducted via computational fluid dynamics, no universal value is known. Simultaneous measurements of fluid velocity and mass concentration are carried out in a water channel for three staggered arrays of cubical obstacles corresponding to isolated flow, wake-interference, and skimming-flow regimes. A passive tracer is released from a continuous point source located at a height z=1.67H, where H is the obstacle height. The results show an increase of Sc_t with height above the canopy for all three arrays, with values at z=2H (Sc_t = 0.6) about double compared to that at z=H. The observed Sc_t agrees well with that modelled by using a simple formulation for Sc_t based on expressions for K_M and D_t published in previous studies. Comparisons with other Sc_t models found in the literature are also presented and discussed.
