Numerical Simulations of the Urban Roughness Sub-Layer : A First Attempt
Numerical Simulations of the Urban Roughness Sub-Layer : A First Attempt
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DOI：
10.1007/978-94-010-0932-4_23
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发表时间：
2000-11
影响因子：
3
通讯作者：
E. Guilloteau;P. Mestayer
中科院分区：
文献类型：
--
作者：
E. Guilloteau;P. Mestayer
大多数介尺度模型使用粗糙度参数来表征地面并计算表面应力。由于城市粗糙度参数的实验测定很少且不太可靠，本文提出了一种基于微尺度数值模拟的新方法，并分析了不同屋顶形状的二维模拟的第一个结果。首先，屋顶形状具有很大的影响：雷诺应力分布和粗糙度子层厚度的巨大差异，增强了阁楼建筑物在屋顶层的交换。与欧洲城市小区的真实空间同质性相比，获得恒定通量层所需的获取似乎也是不现实的。因此，将在不参考恒定通量层理论的情况下开发城市地面引起的摩擦的新参数化。
Most of the mesoscale models use roughness parameters to characterise the ground and to compute the surface stress. As the experimental determinations of the urban roughness parameters are rare and not very reliable, a new methodology based on microscale numerical simulations is presented here and the first results from two-dimensional simulations with different roof shapes are analysed.Firstly, it appears that the roof shape has a large influence : large difference in the Reynolds stress profile and in the roughness sub-layer thickness, enhancement of the exchanges at the roof level by buildings with attic. It also appears that the fetch necessary to obtain a constant flux layer is unrealistic compared to the real spatial homogeneity of quarters in European cities. Consequently, a new parameterisation of the urban ground-induced friction is to be developed without reference to the constant flux layer theory.