网格划分参数对城市街谷行人温湿风模拟的影响--以ENVI-met为例  

The Effects of Grid Partitioning Parameters on Temperature and Humidity Wind Simulation of Pedestrian in Urban Street Valley:A Case of ENVI-Met

作　　者：刘亚敏 林定[1] 朱牧 朱勇兵 Liu Yamin;Lin Ding;Zhu Mu;Zhu Yongbing

机构地区：[1]福州大学空间数据挖掘与信息共享教育部重点实验室 [2]国民核生化灾害防护国家重点实验室

出　　处：《城市建筑》2022年第23期53-59,共7页Urbanism and Architecture

基　　金：福建省自然科学基金(2019Y0005)。

摘　　要：在基于ENVI-met的城市微气候模拟中,存在计算量与网格划分精度权衡问题。本文以高宽比H/W=1的街谷为例,开展计算域的水平网格分辨率(r)、垂直网格伸缩率(k)、嵌套网格数量(n)3个网格划分参数的选择对行人呼吸面计算结果的影响分析。结果表明:首先,在3个参数中,r的合理设置使计算效率提升最显著,应优先考虑r的取值,r取2 m×2 m最适宜,比1 m×1 m的设置快5倍,仅带来较小的计算差异;其次,k取25%最适宜,带来较小偏差的同时节省约1/5的计算时间;最后,计算时间随着n的增加而减小,但差异越来越大,n>4时,差异增幅更大,建议n值取4,差异较小且可提升1倍计算效率。In the simulation of urban microclimate based on ENVImet,there is a tradeoff between the calculation amount and the accuracy of grid partition.This paper analyzes the influence of the selection of three grid partitioning parameters,namely horizontal grid resolution(r),vertical grid expansion rate(k)and the number of nested grids(n),on the computational results of the pedestrian environment,by taking the street valley with an aspect ratio of H/W=1 as an example.The results show that:first of all,among the three parameters,the reasonable setting of r brings the most obvious improvement of computing efficiency and the value of r should be considered first.When calculating pedestrian environment in urban street valleys,it is recommended that 2m×2m is set as the appropriate horizontal grid resolution,which is 5 times faster than 1m×1m in computing efficiency and only brings a small amount of calculation difference.Secondly,k=25%is the most suitable,which can save about 1/5 of the calculation time compared with the nonscaling grid configuration.Finally,the calculation time decreases gradually with the increase of n,and the difference increases.When n>4,the difference increases even more.It is recommended that n=4 can improve the calculation efficiency by one time with relatively small difference.

关 键 词：ENVI-met 网格划分 街谷 数值模拟 

分 类 号：TU99[建筑科学—市政工程]