Abstract: The shape irregularity of sand grains leads to eccentric distances in grains,and their variant positions when they begin to move results in the diversity of eccentric angle.Through theoretical analyses,this paper has given the model that relates threshold wind speed to diameter of grains,eccentric distance,eccentric angle as well as electrostatic force.Then,we numerically simulated the effect of eccentric distance,eccentric angle and electrostatic force on threshold wind speed.The results indicate that when the eccentric distance is equal to 0.05 times of the grain's diameter,the simulating results are coincident with the experimental results well.

Key words: eccentric distance, eccentric angle, electric field in wind-blown sand movement, threshold wind speed