Outdoor measurement of wall pressure on cubical scale model affected by atmospheric turbulent flow
Outdoor measurement of wall pressure on cubical scale model affected by atmospheric turbulent flow
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DOI：
10.1016/j.buildenv.2019.106170
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发表时间：
2019-08
影响因子：
7.4
通讯作者：
C. Hirose;N. Ikegaya;A. Hagishima;J. Tanimoto
中科院分区：
文献类型：
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作者：
C. Hirose;N. Ikegaya;A. Hagishima;J. Tanimoto
大多数室内通风的研究都是在良好控制的流动条件下利用风洞实验（WTEs）或基于计算流体动力学的方法。然而，城市边界层流动与不同的风向和不同的湍流尺度对通风的影响驱动之间的压力差的建筑物在一个块阵列的上，下风向侧的通风仍在讨论中。因此，我们进行了室外实验，在综合室外尺度模型（COSMO）实验地点在城市气候，以澄清建筑物壁压差和接近流之间的关系。室外场地的压力系数与以前WTE期间获得的压力系数相当。因此，在目标块上的风速和压力系数的时间变化进行了详细研究，使用低通滤波操作。过滤后的风速和压力差之间的关系表明，壁压的较慢的时间变化与过滤后的接近流显示出良好的一致性。此外，过滤后的风速和壁压差之间的相关系数量化的湍流和通风率之间的明显的一致性。在此基础上，根据传统模型确定了通风量的统计量，以阐明湍流对自然通风量的影响。平均通风率与短期通风率的比值表明，由于大气流动产生的不同尺度的湍流，短期通风率呈现出剧烈的时间波动。
Most studies on indoor ventilation have utilized wind-tunnel experiments (WTEs) or computational fluid dynamics based approaches under well-controlled flow conditions. However, the effects of urban boundary layer flow with variable wind directions and various turbulence scales on the ventilation driven by the pressure differences between the upwind and downwind sides of a building within a block array is still under discussion. Therefore, we conducted outdoor experiments at comprehensive outdoor scale model (COSMO) experiment sites in an urban climate to clarify the relationships between the building wall pressure differences and the approaching flow. The pressure coefficients for the outdoor site were comparable with those obtained during previous WTEs. Accordingly, temporal variations in the wind speed and pressure coefficient on the target block were investigated in detail using low-pass filtering operations. The relationships between the filtered wind speed and the pressure differences indicate that the slower temporal variations in the wall pressure showed good agreement with the filtered approaching flow. In addition, the correlation coefficient between the filtered wind speed and the wall pressure differences quantified the apparent coherence between the turbulent flow and the ventilation rate. Furthermore, the statistics of the ventilation rate were determined based on the conventional model to clarify the effects of the turbulent flow on the natural ventilation rate. The ratios between the mean and short-term ventilation rates imply that the short-term ventilation rate presented dramatic temporal fluctuations owing to the various scale turbulence generated by the atmospheric flow.