Abstract: The physical effects of upstream flow obstructions such
as vegetation on cross-ventilation phenomena of a building are
important for issues such as indoor thermal comfort. Modelling such
effects in Computational Fluid Dynamics simulations may also be
challenging. The aim of this work is to establish the cross-ventilation
jet behaviour in such complex terrain conditions as well as to provide
guidelines on the implementation of CFD numerical simulations in
order to model complex terrain features such as vegetation in an
efficient manner. The methodology consists of onsite measurements
on a test cell coupled with numerical simulations. It was found
that the cross-ventilation flow is highly turbulent despite the very
low velocities encountered internally within the test cells. While no
direct measurement of the jet direction was made, the measurements
indicate that flow tends to be reversed from the leeward to the
windward side. Modelling such a phenomenon proves challenging
and is strongly influenced by how vegetation is modelled. A solid
vegetation tends to predict better the direction and magnitude of the
flow than a porous vegetation approach. A simplified terrain model
was also shown to provide good comparisons with observation. The
findings have important implications on the study of cross-ventilation
in complex terrain conditions since the flow direction does not remain
trivial, as with the traditional isolated building case.
Abstract: The problems associated with wind predictions of
WAsP model in complex terrain are already the target of several
studies in the last decade. In this paper, the influence of surrounding
orography on accuracy of wind data analysis of a train is
investigated. For the case study, a site with complex surrounding
orography is considered. This site is located in Manjil, one of the
windiest cities of Iran. For having precise evaluation of wind regime
in the site, one-year wind data measurements from two metrological
masts are used. To validate the obtained results from WAsP, the
cross prediction between each mast is performed. The analysis
reveals that WAsP model can estimate the wind speed behavior
accurately. In addition, results show that this software can be used
for predicting the wind regime in flat sites with complex surrounding
orography.