Meaning
Mathematical adjustments for non-Newtonian fluids convert the observed flow rate at the wall into a more accurate representation of the actual shear rate. The rabinowitsch-mooney correction accounts for the fact that shear-thinning liquids do not have a parabolic velocity profile. This formula applies to tube and slit flow but is not used for Newtonian fluids where the shear rate is a simple linear function of the flow rate.
Shear Calculation
Wall shear rates are typically underestimated in raw rheometer data. Applying the rabinowitsch-mooney correction involves finding the slope of the flow curve to adjust the values for the fluid’s specific degree of non-linearity.
Fluid Characterization
Accurate material data is necessary for the design of pumps and dies. Using the rabinowitsch-mooney correction ensures that the viscosity measurements used in simulations reflect the actual behavior in a production line. A pilot result that uses uncorrected data will lead to incorrect predictions of pressure drop and motor load.
Profile Distortion
Velocity profiles in a pipe become flatter as the material becomes more shear-thinning. The rabinowitsch-mooney correction quantifies this distortion to provide a true picture of the velocity at every point in the cross-section. Production yields rely on this accuracy to ensure that the material is not exposed to excessive shear that could break down the molecular structure.
