抄録
Magnetic Resonance Imaging(MRI) is applied to measure velocity inside clay that intrudes at a sudden contraction step. The experiments were conducted with a specially-designed non-magnetic apparatus on which two type of contraction step can be assembled. It is demonstrated that a tagging pulse method gives satisfactory MR images of clay which leads to measure fluid velocity of clay in a quantitative manner. It is also revealed that slip velocity between clay and wall depends on fluid velocity, that is of importance to conduct numerical simulation in determining boundary condition. Finally, expeirmental data are compared with those obtained by numeical calculation where power-law model were applied to clay as non-Newtonian fluid.