COMPUTATION OF RAIN FALLING ON A TALL RECTANGULAR BUILDING

A computational study has been conducted to evaluate raindrop trajecto ries, rain intensities and angles of impact of raindrops on various su rfaces of a CAARC standard building. In the first stage, the pressure distribution around the building is calculated from a 3-D computationa l fluid dynamics (CFD) program. The surface mean pressures are then co mpared with those obtained from a wind tunnel investigation. In the se cond stage, raindrops of various sizes are introduced into the airstre am above and upwind of the building and allowed to hit the building. A Monte-Carlo simulation, based on the computed turbulence timescale, i s used to account for turbulent buffeting of raindrops by wind gusts. The resulting rain impact data are presented here.