Reduced order modelling of an unstructured mesh air pollution model and application in 2D/3D urban street canyons
Reduced order modelling of an unstructured mesh air pollution model and application in 2D/3D urban street canyons
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DOI：
10.1016/j.atmosenv.2014.07.021
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发表时间：
2014-10
影响因子：
5
通讯作者：
F. Fang;T. Zhang;D. Pavlidis;C. Pain;A. Buchan;Ionel M. Navon
中科院分区：
文献类型：
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作者：
F. Fang;T. Zhang;D. Pavlidis;C. Pain;A. Buchan;Ionel M. Navon
针对空气污染有限元（FE）自适应网格模型，提出了一种基于正交分解（POD）的降阶模型。采用非线性项的二次展开式，保证了方法的有效性。这是这种方法第一次通过三维景观应用于空气污染LES湍流模拟。这项工作的新颖之处还包括POD在使用自适应分辨率的FE-LES湍流模型中的应用。针对一系列二维和三维城市街道峡谷流问题，对降阶模型的准确性进行了评估和验证。通过将POD解决方案与从完整的有限元模型中获得的精细细节解决方案进行比较，可以看出准确性得到了保持，其中空气流动的精细细节被捕获，同时减少了计算需求。在下面的示例中，与完整FE模型相比，降阶模型的大小减少了2400倍，而CPU时间减少了完整模型所需时间的98%。
A novel reduced order model (ROM) based on proper orthogonal decomposition (POD) has been developed for a finite-element (FE) adaptive mesh air pollution model. A quadratic expansion of the non-linear terms is employed to ensure the method remained efficient. This is the first time such an approach has been applied to air pollution LES turbulent simulation through three dimensional landscapes. The novelty of this work also includes POD's application within a FE-LES turbulence model that uses adaptive resolution. The accuracy of the reduced order model is assessed and validated for a range of 2D and 3D urban street canyon flow problems. By comparing the POD solutions against the fine detail solutions obtained from the full FE model it is shown that the accuracy is maintained, where fine details of the air flows are captured, whilst the computational requirements are reduced. In the examples presented below the size of the reduced order models is reduced by factors up to 2400 in comparison to the full FE model while the CPU time is reduced by up to 98% of that required by the full model.