Filtering of windborne particles by a natural windbreak
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- 作者：Thomas Bouvet ; Benjamin Loubet ; John D. Wilson and Andree Tuzet
- 关键词：Filtering ; Flux and concentration measurements ; Heavy particle ; Lagrangian Stochastic model ; Maize shelterbelt ; RANS wind flow model ; Windbreak
- 刊名：Boundary-Layer Meteorology
- 出版年：2007
- 出版时间：June, 2007
- 年：2007
- 卷：123
- 期：3
- 页码：481-509
- 全文大小：808 KB
文摘
New measurements of the transport and deposition of artificial heavy particles (glass beads) to a thick ‘shelterbelt’ of maize (width/height ratio W/H ≈ 1.6) are used to test numerical simulations with a Lagrangian stochastic trajectory model driven by the flow field from a RANS (Reynolds-averaged, Navier–Stokes) wind and turbulence model. We illustrate the ambiguity inherent in applying to such a thick windbreak the pre-existing (Raupach et al. 2001; Atmos. Environ. 35, 3373–3383) ‘thin windbreak’ theory of particle filtering by vegetation, and show that the present description, while much more laborious, provides a reasonably satisfactory account of what was measured. A sizeable fraction of the particle flux entering the shelterbelt across its upstream face is lifted out of its volume by the mean updraft induced by the deceleration of the flow in the near-upstream and entry region, and these particles thereby escape deposition in the windbreak.