The snowdrift pattern around two cubical obstacles with varying distance. Measurements and numerical simulations.

Abstract

Snowdrifts around buildings can cause serious problems when formed on undesirable places. The formation of snowdrifts is highly connected to the wind pattern around the building, and the wind pattern is again dependent on the building design and the position of the surrounding buildings. The snowdrift pattern around two 2.5m cubes, positioned close to perpendicular to the wind direction is investigated. The spacing between the cubes was varied to investigate the effects of a local wind speedup between the cubes. The measurements show that a large snowdrift forms between the cubes with the largest spacing between them. A smaller spacing between the cubes results in the disappearance of the centre snowdrift. The reason for this is that the small spacing causes the formation of one horse shoe vortex encircling both cubes and decreasing the amount of snow entering the zone between the cubes. The wind speedup between the cubes will also sweep the area clean of snow. The upwind wind direction, the vertical wind speed profile and the blowing snow flux is measured during the experiments. The experiments were conducted in a valley 3 km wide and 20 km long on Spitsbergen, Norway. The wind in this valley is blowing in the same direction approximately 90% of the time during winter and the site is weil suited for studies of snowdrifts and snowdrifting. The different experiment configurations are investigated through numerical simulations, which confirms the measurements. The numerical method can be applied to other building configurations of Iimited complexity to determine the optimum position of buildings in clusters.