Physical Approach for Sand Flux Quantification and Flow Dynamic Properties Investigation for Fine Sand Grains Transport

Abstract

The purpose of this work is to study sand grains transport for the saltation mode. A numerical simulation approach is adopted with the introduction of a density distribution function. That aims to quantify the transported sand grains, according to the continuum theory. Making a prediction model for transported quantities. In this study, a fine sand grain size is taken into consideration as d=0. 295mm. The inlet wind velocities vary between 8 &18 m/s. The simulation results of sand flux are validated using previous experimental results. The mean horizontal velocity profiles are shown and discussed. It is noted that the sand flux can be described as a Gaussian function which is in good agreement with the experimental results in tunnels for the fine sand groups. This results lead to deduce the lift-off velocity and incident angles profiles distribution. From the sand-coupled wind velocity profile; it can be found that the wind velocity profile near to the surface is modified from logarithmic to a linear function. The variation of the turbulent kinetic energy with increasing wind velocity is further discussed. Finally the energy dissipation is shown. This model will find application in studies of saltation mode on both Earth and Mars.