Laser Doppler measurements of flow in a cone-and-plate rheometer and the effect of cone misalignment

Laser Doppler velocimetry (LDV) is used to measure the flow profile of a Newtonian fluid in a cone-and-plate rheometer. The primary and secondary flow patterns are measured in the ideal geometry. The results confirm prior predictions of flow patterns. Flow profiles are also measured in the misaligned geometry in which the cone axis of rotation is tilted slightly off the perpendicular with the plate surface. Numerical predictions of these flow patterns (Dudgeon and Wedgewood, 1994) are also confirmed.