低含水率沙床的临界起沙风速

针对目前对风沙起动机制的认识有限的现状，采用量钢分析法推导出对湿沙床的起沙有影响的4个无量纲数。经分析得到起沙风速与沙床沙粒粒径和沙床粘结力间的数量关系。通过建立沙床粘结力与含水率、沙粒粒径的关系式，得到临界起沙风速和沙粒粒径，含水率间的定量关系式。认为低含水率沙床的风沙起动风速与颗粒粒径的一次方和沙床含水率的1／4次方成线性关系，此结论与前人的实验结果符合得很好。

On the Threshold Wind Velocity of Sand Movement on Sand Bed with Low Water Content

The knowledge about mechanism of incipient sand movement in wind is still limited nowadays, so dimension analysis method is employed to study the sand movement on wet sand bed. Four dimensionless variables which influence the incipient sand movement in wind are deduced. The quantitative relation among the threshold wind velocity of sand movement, sand diameter and the agglutinate stress of sand bed is obtained with the mentioned dimensionless variables. By modeling the form of water between sand particles in wet sand bed, the correlation among agglutinate stress, water content and sand diameter is set up. Accordingly, a discriminant of threshold condition of sand movement on wet sand bed is sought out. In this discriminant, the threshold wind velocity has a linear relation with sand diameter and the fourth root of water content. This result is coincident with the experimental data.