This current investigation focuses not on the opening location, but on the effect of building opening size and wind incident angle on wind-driven ventilation using the PIV technique, a novel approach to study such problems.
For the current stage of investigation, a uniform wind velocity profile with little turbulence is required for studying the sole effect of opening sizes and wind incident angle.
To change the incident angle
, it is sufficient to rotate the sample about the vertical axis that pass through the center o, while using the second degree of freedom of the sample for adjustments.
For R = 25% (in dotted-dashed line), the decreases in ACR can be found in the range of incident angles
from 90[degrees] to 135[degrees], while a slight increase occurs from 22.
At higher incident angles
and for pipes with higher aspect ratios, the distributions become more uniform as is evident in Fig.
For reflection measurements, to provide a needed incident angle
, a beam may pass through one of five holes in the equator of the sphere.
The incident angle
range of 30-90[degrees] was selected to reduce secondary effects that may be induced by minor surface roughness or instrumental anomalies (3), (5) This angular range yielded the most consistently linear behavior in plots according to Eq.
But the E-plane reflection (parallel polarization) coefficient is very frequently sensitive for larger incident angles
It was tested with two different sunlight incident angles
as in the case of daylighting experiment.
theta]], obtained with a standard glossmeter for a specific incident angle
[theta], is the sum of the contributions of a coherent [G.
Intensity distributions were computed for simulated surfaces with different values of standard deviation of surface height, lateral correlation length, and incident angles
This large value arises primarily from the total reflections that occur for the incident angles
that exceed the critical angle.