Modelling urban airflow and natural ventilation using a GPU-based lattice-Boltzmann method
Modelling urban airflow and natural ventilation using a GPU-based lattice-Boltzmann method
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DOI：
10.1016/j.buildenv.2017.08.048
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发表时间：
2017-11
影响因子：
7.4
通讯作者：
M. King;Amirul Khan;N. Delbosc;Hannah L. Gough;C. Halios;J. Barlow;C. Noakes
中科院分区：
文献类型：
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作者：
M. King;Amirul Khan;N. Delbosc;Hannah L. Gough;C. Halios;J. Barlow;C. Noakes
城市气流和通风潜力的模拟是建筑设计所需要的，然而城市环境中流动的复杂性和瞬态性使得这是一项具有挑战性的任务。本研究的目的是评估能力的格子玻尔兹曼方法（LBM）的代码部署在图形处理单元（GPU）使用大涡亚网格湍流模型的横流通风的理想化立方体建筑在风洞规模。使用ANSYS Fluent进行数值比较。立面压力和通风的立方体进行了调查，平行和垂直的风向与隔离和定期阵列格式的建设。压力，速度和通风率进行比较，从风洞和全尺寸实验的Silsoe立方体的实验数据。模拟与实验值和彼此之间的比较有利。当立方体被其他立方体包围时，模拟表明，逆风建筑物的涡流脱落提供了脉动通风，改善了平行风情况下的气流进入。一项参数研究表明，周围建筑高度加倍对通风有一个小的负面影响，但在垂直面的高水平的下沉气流和流量波动减轻。相比之下，将中心建筑高度增加一倍会产生净正面影响，但会导致两个角度的内部空速都很高。在一个GPU上运行的LBM代码比Fluent快几个数量级，但精度相似。使用LBM方法的模拟时间比Fluent低几个数量级。
Simulation of urban airflow and ventilation potential is desirable for building design, however the complex and transient nature of flows in urban environments makes this a challenging task. This study aims to evaluate the capability of a lattice-Boltzmann method (LBM) code deployed on a graphical processing unit (GPU) using a large eddy sub-grid turbulence model for cross-flow ventilation of an idealised cubical building at wind-tunnel scale. ANSYS Fluent is used as a numerical comparison. Façade pressure and ventilation of the cube are investigated for parallel and perpendicular wind directions with the building in isolation and regular array format. Pressures, velocities and ventilation rates are compared to experimental data from wind tunnel and full-scale experiments of the Silsoe cube. Simulations compare favourably with experimental values and between each other. When the cube was surrounded by other cubes, simulations suggest that vortex shedding from up-wind buildings provides pulsating ventilation, improving airflow ingress in the parallel wind cases. A parametric study showed that doubling surrounding building height had a small negative effect on ventilation but was mitigated by high levels of downdraft and flow fluctuations in the vertical plane. Comparatively, doubling the central building height had a net positive effect but caused high internal airspeeds for both angles. The LBM code running on one GPU was several orders of magnitude faster than Fluent with similar accuracy. Simulation time using the LBM approach was several orders of magnitude lower than Fluent.