New technique for reconstructing instantaneous velocity profiles from viscometric tests: Application to pasty materials

A new technique was proposed for reconstructing the instantaneous velocity profile from viscometry tests. This method is based on a rigorous theory, and since it requires that the fluid does not flow close to the outer cylinder, it is particularly suitable for yield stress fluids. This approach is valid only if there is an unsheared region far from the inner cylinder. The effect of wall slip on the reconstructed velocity profile is to shift the level of the unsheared region to a virtual, constant, finite, velocity level.