Conditional Sampling Of Forest Canopy Gusts
Conditional Sampling Of Forest Canopy Gusts
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森林冠层阵风的条件采样
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
R. Belcher
中科院分区：
文献类型：
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作者：
B. Marshall;C. Wood;B. Gardiner;R. Belcher
用双分量激光多谱勒风速仪在风洞中测量了气弹模型林木的速度。三个不同模型树冠上方的平均速度剖面显示出典型的“剪切层”拐点，当剪切层的特征尺寸被缩放时，湍流特征也是相似的。基于小波的条件采样技术被用于生成与重要的树木弯曲事件同时发生的伪瞬时流场矢量图。讨论了相干阵风的发展与传统的混合层不稳定性描述之间的关系。
Velocity measurements by a two-component laser-Doppler anemometer have been made in a wind-tunnel flow over a forest of aeroelastically scaled model trees. Mean velocity profiles close above three different model canopies exhibit typical ‘shear-layer’ inflections that are similar, as are the turbulence characteristics, when scaled by characteristic dimensions of the shear layer.A wavelet-based conditional sampling technique is used to generate pseudo-instantaneous flow-field vector maps that are concurrent with significant tree bending events. These diagrams show clear evidence of canopy penetration by coherent gusts.A discussion is offered, of the relationship between the development of coherent gusts and conventional descriptions of mixing layer instability.