Large-Eddy Simulation of Turbulent Atmospheric Flow within and above a Forest

PI建议对 大气表面的标量和矢量气象场 一层向下延伸到表面通过树冠层的 高大的植物，如森林。 PI已完成， 报告了这样一个模拟的试点研究。 现有的代码， 它已经运行在一个克雷Y-MP，将是起点， 项目 模型方程求解了一个时间依赖的三维 流场，考虑了植物元素的阻力， 在空气和植物之间进行热交换。 该代码将 进一步发展的气象学的最佳模拟 林，输出将根据发布的字段进行测试 观察，无论是在统计性质和 出现有组织的结构，如弹射/扫掠运动 以及由此产生的标量斜坡和其他空间图案。 计算 将对流场进行研究，试图把大规模的 涡旋结构与时间轨迹中观察到的特征的关系. 固定点 将进行模拟以确定 森林异质性的影响，如边缘或森林 清除/间隙对计算流场和标量场的影响。

The PIs propose to perform large-eddy simulations of the scalar and vector meteorological fields for an atmospheric surface layer extending down to the surface through the canopy layer of tall vegetation such as a forest. The PI has completed and reported a pilot study of such a simulation. The existing code, which has run on a Cray Y-MP, will be the starting point for this project. The model equations solve a time-dependent, 3-dimensional flow field with account taken for the drag of foliage elements and for heat exchange between the air and vegetation. The code will be further developed for optimal simulation of the meteorology of the forest, and output will be tested against published field observations, both in terms of statistical properties and the appearance of organized structures such as ejection/sweep motions and resultant scalar ramps and other spatial patterns. Computed flow fields will be examined in an attempt to link large-scale vorticular structures to signatures observed in time traces at fixed points. Simulations will be performed to determine the influence of forest heterogeneity, such as edge or forest clearing/gap effects on the calculated flow and scalar fields.