Wind loads on rooftop solar photovoltaic panels oriented with varying azimuth angles: A comprehensive wind tunnel analysis

Effects of azimuth angles α, tilt angle β, parapet height ratio H_p/H_s, and building corner modification were examined. The modules at the roof corner were subjected to unfavorable wind loads in a normal setting without α. In contrast, the unfavorable loads occurred on modules at the center of panel row close to the approaching flow for a none-zero α. The wind directions associated with the largest most critical C͝_fm were 45°, 45°, 30°, and 0° at α = 0°, 15°, 30°, and 45°, respectively. The largest most critical mean and negative peak module force coefficients denoted by C‾_fm and C͝_fm increased as α increased. The largest most critical C͝_fm at α = 45° was 19.1%, 12.5%, and 11.9% larger than those at α = 0°, 15°, and 30°, respectively. The more pronounced flow disturbance at larger α would induce larger RMS values of velocities around modules. The larger RMS values of velocities might induce larger C͝_fm on modules at larger α. Both the parapet and corner modification were effective aerodynamic approaches to reduce wind loads. The effect of corner modification on wind loads depended on α. The largest most critical negative C‾_fm and C͝_fm decreased linearly with H_p/H_s for various α.