Distribution Function of Vertical Lift-off Velocity of Sand Particles——A Generalized Form

摘要

Collision between the impacting particles and the sand surface is understood to be critical in the momentum transformations necessary for repeated saltation. This process could be described by the lift-off velocity distribution of particles ejected from the sand surface. On the basis of the experimental data for the lift-off velocity of sand particles obtained by Dong et al., the most probable form of the vertical lift-off velocity distribution function is given out by the statistical inference method, i.e. Kolmogorov-Smirnov goodness of fit test. The statistical result showed that the distribution function of vertical lift-off velocities conforms better to Weibull distribution than to the normal, log-normal, gamma and exponential functions. A general explicit form of an empirical equation is proposed to describe the relationship among the vertical lift-off velocity, the size of sand particles as well as the wind velocity.