水沙流中离散颗粒流动应力关系

在已有的基于膨胀体模型、动理论模型和连续介质理论得到的关系式基础上,分析了水沙流中颗粒流动的应力关系应由摩擦应力、滑动应力和碰撞应力3部分组成,并将颗粒弹性恢复系数引入,对颗粒碰撞项进行了修正。根据颗粒碰撞时间间隔T_c和颗粒弛豫时间T_e的对比,提出了颗粒流动进入碰撞惯性区的临界值,即当T_c/T_e<0.02时,水沙流中颗粒流动碰撞作用占优,可忽略摩擦应力和滑动应力,并将提出的临界值与实验资料进行了比较。利用修正后的水沙流中颗粒流动应力关系,对缓槽水沙流动进行了模拟计算,获得了与实测资料一致的结果。

Stresses of cohesionless solids flow in water-sediment mixture

The stresses of the cohesionless solids flow in water-sediment mixture is a difficulty in the solid-liquid two phase theory.On the bases of the expansion model,the kinetic theory,and the continuous media theory,the stress constitutive relation of cohesionless solids flow with consideration of the coefficient of elastic collision restitution has been obtained,which included the friction stress,the slide stress,and the collision stress.A critical value (Tc/Te<0.02,TC represents the time experienced by a given particle between two consecutive binary collisions,Te is the particle relaxation time) was applied to judge whether the friction stress and the slide stress could be neglected.A simulation of water-sediment flow in inclined chute was carried out to employ the new stress constitutive relation,and the calculated result was good agreement with the experiment data.