ONE- and TWO-Equation Models for Canopy Turbulence
ONE- and TWO-Equation Models for Canopy Turbulence
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DOI：
10.1023/b:boun.0000037333.48760.e5
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发表时间：
2004-10
影响因子：
4.3
通讯作者：
G. Katul;L. Mahrt;D. Poggi;Christophe Sanz
中科院分区：
文献类型：
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作者：
G. Katul;L. Mahrt;D. Poggi;Christophe Sanz
将单方程和二方程（或 K-e）模型计算平均速度 (U)、湍流动能 (K) 和雷诺应力 ðu0w0Þ 的预测能力与在八种植被类型和水槽实验中收集的数据集进行比较。这些数据集的冠层高度 h 范围为 0.12 至 23 m，叶面积指数 (LAI) 范围为 2 至 10m2 m±2。我们发现，对于所有数据集和两个闭合模型，当先验指定混合长度 (lm) 时，测量和建模的 U、K 和 u0w0 非常一致。事实上，测量和建模的 U、K 和 u0w0 之间的均方根误差并不比二阶和三阶闭合方法的已发布值差。在一维建模的背景下，当可以指定 lm 时，包含湍流动力学耗散率 (e) 预算并没有明显的优势。更广泛的含义是，与单方程模型相比，K-e 模型中 e 预算带来的复杂性无需转化为 U、K 和 u0w0 剖面预测能力的提高。
The predictive skills of single-and two-equation (or K–e) models to compute profiles of mean velocity (U), turbulent kinetic energy (K), and Reynolds stresses ðu0w0Þ are compared against datasets collected in eight vegetation types and in a flume experiment. These datasets range in canopy height h from 0.12 to 23 m, and range in leaf area index (LAI) from 2 to 10m2 mÀ2. We found that for all datasets and for both closure models, measured and modelled U, K, and u0w0 agree well when the mixing length (lm) is a priori specified. In fact, the root-mean squared error between measured and modelled U, K, and u0w0 is no worse than published values for second-and third-order closure approaches. Within the context of onedimensional modelling, there is no clear advantage to including a turbulent kinetic dissipation rate (e) budget when lm can be specified instead. The broader implication is that the added complexity introduced by the e budget in K–e models need not translate into improved predictive skills of U, K, and u0w0 profiles when compared to single-equation models.