论文部分内容阅读
长期以来，专家们一直认为泥沙在动水中的沉速小于在静水中的沉速是由于动水中向上紊速阻碍泥沙沉降的结果。本文认为，时均向上紊速和向下紊速是相等的，紊速对泥沙沉速的影响，只有在悬沙浓度沿垂线分布存在梯度时才能反映出来，梯度越大，动水沉速减少越多。进而应用扩散理论导得泥沙动水沉速表达式，并对沉沙池计算中的准静水沉降法进行了修正，修正式的计算结果与实测资料十分吻合。本文提出的概念，为今后进一步研究泥沙的动水沉速开辟了一条新的途径。
For a long time, experts have always believed that the settling velocity of sediment in moving water is less than the settling velocity in still water as a result of the upward turbulence in the moving water hinders the sedimentation. This paper argues that the average upward and downward turbulence velocities are equal, and the effect of turbulence on the sedimentation velocity is only reflected when there is a gradient along the vertical distribution of suspended sediment concentration. The greater the gradient, The more speed reduction. Furthermore, the diffusion theory is used to derive the expression of sediment hydrodynamic velocity, and the quasi-hydrostatic settling method in settling basin is modified. The calculated result is in good agreement with the measured data. The concept proposed in this paper opens up a new way for further research on the sedimentation speed of sediment.