A vane rheometer is commonly used to determine the rheological properties of suspensions, colloids such as cement-based materials, many of which can be described as a Bingham fluid. Due to the complex flow geometry of the vane rheometer, relating measured quantities (torque and angular velocity) to rheological properties (yield stress and viscosity), represents a challenge. In this study, the smoothed particle hydrodynamics (SPH) method was used to simulate the flow of Bingham fluids in 2D vane and coaxial cylinders. First, the Bingham/Papanastasiou constitutive model was implemented into the SPH approach and the code was validated by conducting a series of standard tests and comparing simulation results to well established theoretical predictions. Numerical simulations for the flow of Newtonian fluids in 2D vane and coaxial cylinder rheometers were then performed. A comparison to experimental data is also made to verify the application of SPH method in realistic flow geometry. Finally, a parametric study for the flow of Bingham fluids with different yield stresses in vane and coaxial cylinder rheometers was developed, and the stress and velocity profiles, especially in the vicinity of the vane blades, were computed. Comparing the calculated stress (torques) between the two rheometers allowed us to test the validity of the assumption that the vane could be considered as a cylinder for measuring the rheological properties of Bingham fluids.
Citation: Journal of Non-Newtonian Fluid Mechanics
Pub Type: Journals
Bingham fluid, non-Newtonian fluid, Papanastasiou s model, smoothed particle hydrodynamics (SPH), vane rheometer