Experiments and CFD Predictions of Particles Velocity and Trajectory in Flow with Non-Newtonian Fluid through a Partially Obstructed Duct

Dynamic of particles in annular fluid flow is a very relevant subject for many industrial applications, especially for the oil and gas industry. Successful drilling is, to a large extent, dependent upon the ability of the drilling fluid to clean the hole by conveying the cuttings to the surface. The aim of this work was to evaluate experimentally and through numerical simulations, the helical path and the axial mean velocity developed by glass beads with diameter of 2.7 mm flowing with a non-Newtonian fluid through a partially obstructed annulus. Experimental data are reported for flow of 1 m3/h of an aqueous solution with 0.5% Xanthan gum through concentric annulus with partial obstruction of 6 mm and a 183 rpm rotation of the inner cylinder. Techniques of computational fluid dynamics (CFD) were applied to obtain detailed information about the flow field, allowing to estimate the radial position of launching of particles in the range of 35.5 mm to 39.1 mm. Comparisons between numerical calculations and the flow data indicated, in general, a very good agreement.