基于水沙混合流的基本控制方程，考虑泥沙颗粒间相互作用形成的剪切应力，引入局部化ＭｏｎｉｎＯｂｕｋｈｏｖ长度尺度以计入密度分层浮力效应，建立了明渠定常、均匀水沙混合流流速分布的严格理论模式，理论结果与实测资料吻合甚好，该模式普遍适用于低含沙量和高含沙量流动．本文的分析支持基于ＶｏｎＫａｒｍａｎ常数不变之观点 Based on the basic governing equation of mixed flow of water and sediment, considering the shear stress formed by the interaction of sediment particles, the local MoninObukhov length scale is introduced to account for the buoyancy effect of density stratification, and a steady and uniform mixed flow of sand and water is established The rigorous theoretical model of velocity distribution and the theoretical results are in good agreement with the measured data. This model is generally applicable to low sediment concentration and high sediment concentration flows. The analysis in this paper supports the view based on the constant VonKarman constant