两个计算流体动力学模型和一个半日尺度模型的适用性,用于预测城市热岛循环
Huanhuan Wang1, Qun Wang2, Yifan Fan3,4
1Department of Mechanical Engineering, The University of Hong Kong, Hong Kong.
概括
在比较城市空气流模型时,这项研究发现,像PALM和Fluent这样的微尺度模型对于城市热岛循环 (UHIC) 的准确性比WRF这样的中尺度模型更高. 微尺度模型提供了更好的细节,但计算成本更高.
科学领域:
- 环境科学环境科学
- 大气科学 大气科学
- 城市规划是城市规划.
背景情况:
- 预测城市规模的空气流,包括城市热岛循环 (UHIC),是复杂的,因为微观和中等风之间的相互作用.
- 微尺度 (例如,CFD) 和中尺度 (例如,WRF) 模型都用于UHIC,但它们的模拟能力的直接比较缺乏.
- 中尺度模型难以处理建筑特有的细节和细度流,导致越来越多地使用像PALM和Fluent这样的微尺度模型.
研究的目的:
- 评估介质尺度 (WRF) 和微尺度 (流体,PALM) 模型之间的权衡,以模拟城市热岛循环.
- 为了比较城市规模空气流量预测的不同建模方法的准确性和计算成本.
- 为选择基于准确性和计算效率的适当城市空气流预测工具提供指导.
主要方法:
- 使用WRF,Fluent和PALM在理想化的方形城市上模拟城市热岛循环.
- 对比了每个模型在捕捉复杂的流动模式,特别是局部地面效应的准确性.
- 评估了与每个建模方法相关的计算成本.
主要成果:
- 在计算上,WRF是高效的 (成本比微尺度模型低10倍),但精度较低,特别是在地面层效果方面.
- 通过模拟更细微的细节,Fluent和PALM提供了更高的准确性,但会产生更高的计算成本.
- PALM和Fluent显示了类似的准确性,而PALM在计算上比Fluent更高效. 帕尔姆的卡特西亚格子限制了对复杂建筑形状的处理.
结论:
- 微尺度模型 (PALM,Fluent) 与中尺度模型 (WRF) 相比,为城市热岛循环提供了更高的准确性.
- 模型之间的选择取决于平衡精度 (微尺度) 与计算成本 (大尺度) 的需求.
- PALM是一个计算效率高的微尺度选项,尽管Fluent可能更适合复杂的城市几何形状.
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