Wind
Driven Flow through Openings – A Review of Discharge Coefficients
P. Karava, T. Stathopoulos
and A.K. Athienitis
Centre for
Building Studies, Department of Building, Civil and Environmental
Engineering,
Concordia University, Montreal, Quebec, Canada
Abstract
This paper reviews the
current literature on discharge coefficients (CD) of openings
and compares different studies for wind-driven cross-ventilation.
Considerable variation of discharge coefficients with opening porosity,
configuration (shape and location in the façade), wind angle and Reynolds
number is shown. Consequently, the use of a constant CD value
such as that given in textbooks or other sources might be an invalid
simplification. Scaling, upstream flow conditions, internal partitions and
the assumptions of turbulent flow, sealed body and energy dissipation made
for the application of the orifice equation should be considered in wind
tunnel experiments of cross-ventilation.
Key words: cross-ventilation,
discharge coefficient, opening configuration, opening porosity,
wind-driven flow.
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