Estimating the effect of snowdrift formation on turbulent airflow and subsequent snowdrift around three types of fences

This study investigated the effect of formed snowdrifts in advance on the turbulent flow and subsequent snowdrift distribution around three types of snow fences in a numerical simulation. The simulation for an 8 h drifting snow event was conducted with updating the bottom boundaries following the snowdrift structure every 2 h. The calculation domains were flat ground surfaces installed three types of solid fences—two-dimensional fence, three-dimensional fence, and two-dimensional fence with a bottom gap. Snowdrift height on the windward side of the two-dimensional fence was higher in the updating experiment than in no-updating one because wind profiles and snow trajectories were modified depending on the previous snowdrift shapes. Around the three-dimensional and bottom-gap fences, differences of snowdrift height between with and without updating bottom boundaries were generated on the leeward areas. Snowdrifts on the leeward side of these fences were formed on far areas in the no-updating experiment, but the experiment considering the previous snowdrift structures developed snowdrifts closer to the fence. These results suggested that snowdrift development on the leeward side of obstacles could be overestimated if the previous snowdrift structure were neglected in numerical simulations. • We calculated snowdrifts updating the bottom boundary due to snowdrift formation. • Snowdrifts around three types of fences were focused on. • Previous snowdrift modified calculated wind profiles, especially near obstacles. • Neglecting previous snowdrifts can overestimate snowdrift on leeward of obstacles. • Change of bottom boundaries due to snowdrift is important for accurate estimation.