a test case for the analysis of the ventilation in a wind ... · pdf file“two-sided wind...
TRANSCRIPT
A Test Case for the Analysis of the
ventilation in a Wind Catcher
© 2017 Vento CFD srl
Contents
The Windcatcher
The CFD and Wind Tunnel reference
VENTO AEC analysis
Comments
© 2017 Vento CFD srl
The Windcatcher
The Windcatcher is a traditional Persian architectural element that uses the wind to create a natural ventilation in buildings.
Windcatchers date back to 4,000 years B.C.
© 2017 Vento CFD srl
The Windcatcher
A two-sided Windcatcher catches the wind by the windward opening and forces the air to circulate inside the building.
The air then exits the building from the leeward windcatcher opening and also from another opening in the building.
© 2017 Vento CFD srl
The CFD and Wind Tunnel reference
The reference:
“Two-sided wind catcher performance evaluation
using experimental, numerical and analytical
modeling”
H. Montazeri et al., Renewable Energy, 35, 2010
.
© 2017 Vento CFD srl
The CFD and Wind Tunnel reference
The two-sided windcatcher is
placed in the wind tunnel.
The underlying building is not in
the wind tunnel.
The scale of the model is 1:40
© 2017 Vento CFD srl
VENTO AEC analysis
(*) time from STL import to start of simulation
Grid 2 case used the Grid 1 setup
(&) simulation time on a 4-core desktop
Setup (*) Simulation (&)
Grid 1 10' 86'
Grid 2 3' 400'
The analysis was carried out on 2 grids of
4.1M cells and 1.3M cells.
The outdoor layout was used. Scale 1:4
© 2017 Vento CFD srl
VENTO AEC analysis
vertical velocity color map on an XY section of the windcatcher at
mid height. The windward side above, the leeward side below. Coarse grid (left) and fine grid (right) results.
© 2017 Vento CFD srl
VENTO AEC analysis
streamlines and flow structure (left), color map of the pressure
on the symmetry plane (right)
© 2017 Vento CFD srl
VENTO AEC analysis
Percentage of the wind mass flow rate entering the windward opening that exits from the leeward opening.
The rest of the wind mass flow rate exits from the underlying
building opening
Experiments (ref.) 48
CFD results (ref.) various models 46, 49, 52
VENTO AEC results 45 (grid 1), 52 (grid 2)
© 2017 Vento CFD srl
Comments
Despite the fact that the Reynolds number used by VENTO AEC is
ten times higher, and that the domain dimensions and layout
differ from the wind tunnel analysis, the windcatcher analysed by
VENTO AEC shows the same performance. The ability to create
an indoor ventilation is qualitatively and quantitatively correct.
If a wind tunnel STL is provided, VENTO AEC indoor layout can be
used to reproduce exactly the same domain and the same
experimental conditions
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