模型沙容重和流变及沉降特性的试验研究

目前河工泥沙模型试验中常采用的模型沙主要有电木粉、塑料沙、煤粉、煤灰等，通过对这几种模型沙的容重、流变及沉降特性进行试验研究和总结，其主要结论是：模型沙的重率是比较稳定的，但其干容重随时间的延长而逐渐增大，并趋于一稳定值；模型沙浑水一般皆属于牛顿体或宾汉体单颗粒模型沙沉速服从斯托克斯定律和武汉水利电力学院公式，而群体沉速仍用一般规律进行描述。

Experimental Study on Density, Viscosity Fluidity and Falling Velocity of the Model Material

At present time, several kinds of model material are often used in the river engineering scale model, such as phenolics granules, polystrene plastic granules, coal granuler and coal ash gran-ules. In this paper, the density, the viscosity fiuidity and the falling velocity about these model mate-rials are studied through the experiment. The main conclusions are as follows: (1) The density of theinedel material is stable, but the dry density of the model material increases with time, and tends to aconstant. (2) Fluids of the medel material are Neivtonian fluids or Bingham fluid' The relative viscos-ity coefficient follows the equation M = (1 -kS.) -2.5 for the brown phenolics granules, black phenolics granules, coal granules and coal ash granules and the equation for the polystrene plastic granules, white phenolics granules and natural sediment. (3)In the physical scale model of the high sediment concentration, it is important to consider the similarity of the viscosity of the fluid- (4) The falling velocity of the single model granule folows the stokes law and the formula of Wuhan University of Water Resource and Electric Power. And the falling velocity of the massive model material follows the general.