Pipe Flow of Sphere Suspensions having a Power-Law-Dependent Fluid Matrix
Nicos Martys, William L. George, Ryan P Murphy, Kathleen M Weigandt
Measurement and prediction of suspension flow properties in cylindrical geometries represents a significant challenge for both the experimentalist and modeller. In this paper, results of a computational study of suspension flow in a pipe geometry using a computational method based on the Smooth Particle Hydrodynamics are presented. Flow fields and the spatial distribution of solid spherical inclusions for the case of pipe flow will be shown as a function of the matrix fluid properties, (including Newtonian, shear thinning and shear thickening), driving force, and volume fraction of particles. Simulation results of suspension flow are consistent with previous work of suspensions with a Newtonian fluid matrix. A strong effective slip phenomenon is shown for the case of a suspension with a shear thinning fluid matrix despite adherence to no-slip boundary conditions. A simple scaling ansatz is given to describe the change of flow rate with driving force. At a volume fraction of approximately $40 \% $ and higher, there is strong evidence of ordering. This feature is illuminated using a small angle scattering algorithm and comparison to experimental studies using neutron scattering. Issues related to proper experimental characterization of rheological properties for pumping and printing of cement based materials are discussed.
Journal of Rheology
Rheology, suspensions, pumping, smoothed particle hydrodynamics, cement based materials