Double concentric cylinder geometry with slotted rotor to measure the yield stress of complex systems: A numerical study.

Based on the success of the slotted plate device [Zhu et al., “A slotted plate device for measuring yield stress,” J. Rheol. 45, 1105–1122 (2001)] a numerical analysis is performed for a double concentric cylinder geometry with slotted rotor to measure the yield stress of complex systems such as suspensions. This method overcomes the wall-slip problem, it also takes advantage of the amenable features of commercial rheometers. A finite element model is developed to simulate the deformation and stress distribution in the double concentric cylinder geometry under various wall and material interactions (no-slip, 50% slip, and free slip conditions). Our numerical results show that this geometry greatly reduces the wall slip effect and it proves to be a promising technique for measuring the yield stress of complex systems. [ABSTRACT FROM AUTHOR]