对均匀沙流体起动风速的研究

从学术观点和方法上将研究边界层流动对粗糙壁面的摩擦切应力与研究均匀沙流体起动风速统一了起来，既关心了布满均匀沙的沙床上颗粒的流体起动风，又关心了稀疏分布着均匀颗粒的光滑地表上沙子的流体起动风速，得出了用边界层外参考风速表示的流体起动风速随颗粒分布密度的增加呈指数增长规律。而用摩阻流速表示的流体起动风速与颗粒分布密度的二分之一次方成正比的规律，与有关实验数据取得一致。当颗粒的分布密度逐渐增大时，本文得到的均匀沙流体起动风速公式最终退化为传统的均匀沙流体起动风速公式。

Threshold wind-velocity for single size sand

An improved theory is developed to illuminate distributing density of arbitrary shaped roughness elements on a wall and how wind velocity above the turbulent boundary layer in?uences shear velocity. The theory is used to study the threshold velocity of single size sand, and obtain that the threshold velocity represented by wind velocity above the turbulent boundary layer is proportional to the exponential function of sand distributing density when the threshold velocity represented by shear velocity is proportional to the square root of sand distributing density. Let sand distributing density increase, the relationship will become the classical wind initiation formula of single size sand eventually.