Drag and relaxation in a bentonite clay suspension

  title={Drag and relaxation in a bentonite clay suspension},
  author={N. Paul Chafe and John R. de Bruyn},
We measure the drag force on a sphere moving slowly through a 6% by weight suspension of bentonite clay particles in water. The steady state drag force depends only weakly of the speed of the sphere, indicating that yield stress effects dominate the drag in the range of pulling speeds studied. The drag force increases as a function of time as the suspension gels. The yield stress of the suspension as a function of suspension age is determined from the zero-velocity intercept of our force… CONTINUE READING