Flow Curves in the Centered Cylindrical Couette Geometry of a Polyethylene Oxide Solution

Abstract

Polyethylene oxide solutions have a behavioral flexibility that provides researchers with the opportunity to use constitutive law models in a variety of ways for their MRI characterization. Our results obtained in numerical simulation carried out in 2D and 3D for speed profiles of a solution of PEO deployed by the simple method of the cylindrical Couette geometry considering the fluid Newtonian defect, allowed to identify the behavior of fluid complex (rheo-fluidifying threshold fluid). The relevance and the interest of the method are examined by analyzing these results generated by the numerical data obtained, since these profiles depend on the non-Newtonian properties of the fluid which one does not know a priori and which one seeks to measure by postulating first to the power law of Ostwald, then to the truncated power law.

Geometrical and Experimental Conditions for the Homogeneous and Inhomogeneous Flows of the Polyethylene Oxide Solution in the Cylinder of Couette

“…Profiles obtained following a digital simulation with MATLABR2008b at an angular velocity ω = 0,9 rd./s for the first figure and with a variation angular velocity of (0,02 to 0,9) rd./s for the second. They translate the behavior of this structure in the geometry of Couette (coexistence of two areas different and the existence from an unstable zone in the curve of flow of material) [5], [6], [7], [8].…”

“…The equation (5) reformulates the equation (4) by taking account of the assumption that the inertias are negligible compared to the forces of viscosity and so that, the rate of flow takes into account the property of the solution related to the number of Reynold R e = (ω R 1 e)/µ with µ = η/ρ, via a constant. The geometry of the device of Couette has the internal radius R 1 and external radius R 2 [5].…”

“…rc marks the interface between the solid zone and the liquid zone for a flow in the geometry. The variation of the shear rate with the velocity profile from γ • 2 to γ • 1is observed before falling into the blocked zone[5].…”

“…Local 2D-dimensional velocity profiles in the air gap of a Couette cylinder with the variation of the experimental parameters: V(ω, r)/V0 for different rotational angular velocities (0.02 to 0, 9 rd. / s) imposed on the inner cylinder[5].…”