Other structures - Wind Loading of Structures - page 331

stagnation of the flow occurs on the wall, both above and below the canopy. In this
situation, the mean net force coefficients are low, but turbulence produces finite peak
loads in both directions.
Figure 14.11 Peak uplift force coefficients for
attached canopies (Jancauskas and Holmes,
1985).
Parapets and their effect on roof pressures on flat roofs have been the subject of several
wind-tunnel studies. In the early work, there were some conflicting conclusions drawn by
different laboratories, but the issue was largely resolved using large models and a high
density of pressure tappings (Kind, 1988). With or without parapets, the worst suction
peaks occur in small zones near the upwind corner of the roof, for wind directions nearly
bisecting the corner. The worst suction coefficients decrease monotonically with
increasing relative parapet height. The amount of the reduction also depends on the
height/width ratio of the building to which the parapet is attached (see also Section 8.6).
14.4.2 Solar panels on roofs
The wind loads on solar panels attached to the roofs of a building are closely related to
the flow over the roofs of the building itself, as the latter is a much larger bluff body.
Figure 14.12 shows the various geometric variables that are significant in determining the
wind loads on solar collector panels on a pitched roof building (Tieleman et al., 1980).