Q. Formation of pedestrian level winds around buildings?
When a building blocks the wind blowing across it, part of the wind will escape over the top of the building. Some will pass around the edges of building whereas a majority of the wind will get down to the ground. Channelling effect of wind for an escaping path together with high wind speeds associated with higher elevations, produces high wind speeds in the region at base of the building. At the baselevel of the building, there are 3 locations of strong pedestrian level winds:
(i) Arcade passages - wind flow is produced by pressure difference between front and back of the building.
(ii) At the front of building - high wind is generated by standing vortex.
(iii)At the corners of building - high wind is induced by corner flow.