摘要:
一般认为泥浆在运动时候,它的力学性质已经有别于通常的牛顿流体而是宾汉体了.因此剪应力应该用宾汉体的剪应力关系式.本文作者则持另外一种见解.认为泥浆是一种接近于沥青一类的粘性极大,弛豫时间极长的流体.本文讨论了泥浆的力学性质,并且进一步讨论了圆球在泥浆中作匀速直线运动时所受到的阻力.在讨论过程中,我们利用了人们熟知的粘性流体绕圆球运动的Stokes解,得到了一个简单的阻力公式.当圆球在重力和浮力作用下在泥浆中作沉淀运动时候,我们求出了沉降速度.在沉降速度为零时候,我们就可以求出"不沉粒径"和"宾汉体极限剪应力"的关系.我们把计算结果得到的理论公式和陕西水科所及黄委会水科所等单位的实验数据[1][2]进行了比较,结果是令人满意的.
Abstract:
The shear stress of the slurry flowing in the tube or two-dimensional channel is epressed by the shear stress of Bingham fluid,usually.ie Where τB is the yield stress of Bingham fluid and η is the coefficient of rigidity.The author disapproves this point of view The author thinks that the mechanical property of the slurry may be more like that of highly viscous fluid than that of Bingham fluid.Basing on this idea,we adopt another method to treat the mechanical problem.We assume that,for the case of small Reynolds number,the velocity distribution of the slurry is very close to that of Stokes solution,Thus,we map apply the method.of effective viscosity to calculate the resistance force of a sphere moving in the slurry with uniform velocity.