METHOD OF DETERMINING NON-NEWTONIAN VISCOSITY Russian patent published in 2011 - IPC G01N11/14 

FIELD: physics.

SUBSTANCE: method of determining non-Newtonian viscosity involves feeding the medium under investigation onto a measuring surface. The method also involves measuring a parameter and calculating viscosity of a non-Newtonian liquid. The measuring surface used is a flat disc and the medium (1) under investigation is fed through an outlet hole onto the centre of a rotating disc (3) at a certain distance r from the axis of rotation and the edge of the disc. After establishing constant rotation speed, thickness δ₀ of the film one or more points is measured. At the same flow rate of the medium, the rotation speed of the disc is measured and similar measurements are repeatedly taken while repeating the operation several times and according to the functional relationship: where γ is shear velocity, τ_m=ρw²rδ₀ is the shearing stress on the wall, ρ is density of the non-Newtonian liquid, δ₀ is film thickness, r is coordinate for measuring film thickness from the centre, w is the angular speed of the disc, Q is volume flow rate, Φ=Qρ²rw⁴/2π. The rheological curve is plotted.

EFFECT: wider measurement range due to generation of any pressure gradient owing to change in revolutions of the disc of the viscosimetre, and simple and accurate measurement of viscosity of non-Newtonian liquids.

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