The test measurements were analysed in order to find some general
relationships useful for parametric design analysis.
No correlation is found between mean 
values
and wind speed on the mirror.
The reason is that we have in many cases large differences in
mean pressure on the four pressure taps and also in some instances
a reversed flow on the mirror, whereby the mirror upper surface
is actually under a mean negative pressure.
On the contrary a correlation between 
and wind speed
is well established and is independent of the wind direction.
Recalling that 
is referred to the external reference
speed 
:
we introduce a similar coefficient referred to the wind speed U measured on the mirror:
obtaining the relationship
Fig. 
is a scatter plot of this relationship.
The correlation is independent of the azimuth angle and of the
venting configuration of the enclosure. The coefficient 
depends only on the zenith angle:
, for zenith angle >= 35 deg
, for zenith angle = 10 deg
Figure: Correlation between 
( rms of the pressure coefficient) and mean wind
speed on the primary mirror.
Although it cannot be generalized to other types of
enclosures, this result
suggests that simple parameterizations between speed measurements and
pressure fluctuations should be looked for in the
study of a new enclosure.
Since the ratio 
is a parameter that can be adjusted by
acting on the ventilation devices of the enclosure (louvers,
windscreen), a relationship of the type () will be
particularly useful for parametric design analysis as well as for
operational simulations of the use of the enclosure venting devices.
