The analysis of variations in the saltating sand transfer velocity
A.V. Karpov, R.A. Gushchin, O.I. Datsenko
A.M. Obukhov Institute of Atmospheric Physics Russian Academy of Sciences, Pyzhevsky per., 3, 119017, Moscow, Russia
Keywords: динамика сальтации, прямые и обратные задачи, массовый поток сальтации, коэффициент скольжения, методика восстановления, saltation dynamics, direct and indirect problems, mass saltation flux, sliding coefficient, retrieving method
Abstract
A technique is developed for retrieving the vertical profile of the mass saltation flux from measurements of the saltating sand mass concentration and wind velocity in the surface air layer. The technique is based on the solution of direct and inverse problems of the saltation sand dynamics. In order to estimate the saltating sand sliding coefficient, calculation results are compared with measurements in wind channels. The conditions for the saltating sand trajectories to fall in the altitude ranges from 0.5 to 1.0 cm and from 1.0 to 2.0 cm are ascertained. The effects of the diameter, sand grain liftoff velocity and angle, and the friction velocity on the sliding coefficient are analyzed. The sliding coefficient for sand particles of 100 μm diameter is estimated for the first time.
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