Indoor airflow and thermal comfort in a cross-ventilated building within an urban-like block array using large-eddy simulations
Indoor airflow and thermal comfort in a cross-ventilated building within an urban-like block array using large-eddy simulations
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DOI：
10.1016/j.buildenv.2021.107811
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发表时间：
2021-04-01
影响因子：
7.4
通讯作者：
Tanimoto, J.
中科院分区：
文献类型：
--
作者：
Hirose, C.;Ikegaya, N.;Tanimoto, J.
这项研究的特点是室内气流和居住者？基于大涡模拟（LES）的通用立方体阵列遮蔽的交叉通风建筑模型中的热感觉。四个通风模型，其中包括不同的交叉通风口，流向（STR）和横向（LAT）窗口，和块的安排，格子型正方形（SQ）和交错（ST）模式，进行了检查，以了解以下几何导向的功能：i）通风模型内和开口处风速的时间和空间偏差，ii）速度数据的时间和空间分辨率对通气率估计精度的影响，以及iii）用精心模拟的速度数据计算的预测平均投票（PMV）和预测不满意百分比（PPD）指数。当改变开口位置的条件时，开口处的脉动法向速度分布的差异比改变建筑物布置时观察到的差异更显著。因此，在STR条件下的通风量是合理的估计，仅使用时间平均流量在迎风开口的中心位置;同时，当反向流的贡献被忽略在开口处，在LAT条件下的通风量被大大低估，使用高分辨率的速度数据在开口处。根据热舒适性评估在空气温度为26？在自然通风的建筑物中、低层，STR和LAT的面积平均PMV值的差异在0.7和0.9之间，导致PPD值相差5%。
This study characterizes the indoor airflow and occupants? thermal sensations in a cross-ventilated building model sheltered by generic cube arrays based on large-eddy simulations (LESs). Four ventilation models, which comprise different cross-ventilating openings, streamwise (STR) and lateral (LAT) windows, and block arrangements, lattice-type square (SQ) and staggered (ST) patterns, were examined to understand the following geometry-oriented features: i) the temporal and spatial deviations of wind speed at openings and inside the ventilation models, ii) effects of time and space resolutions for the velocity data on the estimation accuracy of the ventilation rate, and iii) predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD) indices calculated with elaborately simulated velocity data. The difference in distribution of fluctuating normal velocity at openings was more significant when varying the conditions of the opening locations than that observed when varying the building arrangements. Therefore, the ventilation rates in the STR conditions were reasonably estimated using only the time-averaged flow rate at the center position of the windward opening; meanwhile, when the contributions of reverse flow were ignored at the openings, the ventilation rates in the LAT conditions were drastically underestimated using highly resolved velocity data at openings. Based on the thermal comfort assessment at an air temperature of 26?C, the discrepancies of area-averaged PMV values between STR and LAT cases were within 0.7 and 0.9 at the lower and middle heights of naturally ventilated buildings, resulting in a 5% difference in the PPD values.