平坦沙面起沙率的实验测量

he study of the dust emission perpendicular to the sand surface is meaningful for understanding the formation mechanisms of wind-sand currents and dust storms. In this paper, the dust emission rate was measured using the Particle Image Velocimetry technique in a wind tunnel. The velocity of sand grains was calculated the cross-correlation arithmetic based on the PIV technique, and then the displacement was obtained from the time relation from both imagines. Based on the above calculation, the number of sand grains moving up from the sand surface could be achieved, and it was found that the dust emission rate varies linearly with the square of the friction speed from the analysis using the method of least squares and the corresponding formula was obtained. The analysis of the distribution of the grain size indicates that the grain size varies following the normal distribution. As the friction speed increased of the impact of the large particles will be larger.