动荡的边界层中的多层建筑的唤醒特征
Cameron Southgate-Ash1, Abhishek Mishra1, Sue Grimmond2
1Department of Mechanical Engineering Sciences, Environmental Flow Research Centre (EnFlo), University of Surrey, Guildford, UK.
概括
城市碎形几何显著改变风流,影响行人舒适度和空气质量. 引入较小的长度尺度可以减少流散,这可能有助于工程应用,例如减少振动.
科学领域:
- 流体动力学 流体动力学
- 城市气象学 城市气象
- 空气动力学 在空气动力学.
背景情况:
- 具有多层次粗度的城市形态显著影响风力结构,影响街道级行人舒适度和空气质量.
- 大多数城市流量研究通过使用单个长度尺度的立方体建筑来简化,可能会忽视复杂的流动动力学.
研究的目的:
- 调查城市形式中额外的长度尺度对风流特征的影响.
- 为了评估立方体建筑物的碎形代如何影响拖拉力,散,流强度和流流失.
主要方法:
- 风洞实验使用六种建筑形式 (两个参考立方体和两个分形代) 进行,平均尺寸相同,但长度尺度不同.
- 实验是在深层流边界层内进行的,以模拟现实的城市风条件.
主要成果:
- 建筑长度尺度的变化对阻力产生了不可忽视的影响 (标准建筑高达5%,高层建筑高达13%).
- 增加的长度尺度改变了觉醒的横向扩散和流强度;较小的尺度导致了更低的近觉醒和更高的远觉醒波动.
- 随着系统地引入较小的长度尺度,旋流失强度下降.
结论:
- 在城市流量模型中省略额外的长度尺度可能会导致拖动和唤醒恢复估计的不准确性.
- 通过碎形代来减少流散射强度,可以带来潜在的工程效益,例如减轻结构振动.
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