Drifting Snow Similitude

The problem of modeling the drifting of snow in a boundary layer wind tunnel is reviewed. The important dimensionless parameters that govern the drifting phenomena are introduced. Theoretical means such as the equations for mass transport rate of saltating material and the particle trajectory equations of motion are used to combine these dimensionless parameters into five similitude parameters. These final five parameters are analyzed as to their relative importance in the wind tunnel simulation of drifting snow. The properties of snow and of possible modeling materials are examined, and the final results of a previous study involving simulation of sand movement are presented. Use of a variety of model particles and the variation of vertical distortion of the modeled topography can aid in application of the results to full-scale conditions. Quantitative scaling can be achieved by measurement of the rate of accumulation of drifting material.