is in good agreement with the prediction formula proposed by Cornish. (2004), 'Estimation of the parameters of Herschel–Bulkley fluid under wall slip using a combination of capillary and squeeze flow viscometers', Rheologica Acta, 43 (1): 80–88, doi: 10. This relationship between the apparent viscosity and the characteristic shear rate. developed 2-D flows of liquids with a rate-dependent viscosity, the calculation. Apparent viscosity (sometimes denoted ) 1 is a rheological property calculated from rheometer readings performed by a Mud engineer on drilling fluid. An iterative procedure is required, as the pressure drop is required to initiate the calculations as well as be the outcome of them. At the end of one single point measurement, an apparent viscosity a. The pressure drop can then be calculated, given a suitable friction factor correlation. Each apparent value is one point of the viscosity function (eta over shear rate). This is the apparent viscosity or apparent shear viscosity.

Therefore, you need to specify at which shear rate a viscosity value was determined. When both ends of the coupling are spinning at the same rotational speed, the viscosity of the dilatant fluid is minimal, but if the ends of the coupling differ in speed, the coupling fluid. 1 Etymology 2 Definition Toggle Definition subsection 2.1 Dynamic viscosity 2.2 Kinematic viscosity 2.

They are in common use in viscous couplings in automobiles. They show a decrease in viscosity with increasing shear rate. Dilatant, or shear-thickening fluids increase in apparent viscosity at higher shear rates. These curves are typical for pseudo plastic materials. Three parameters characterize this relationship: the consistency k, the flow index n, and the yield shear stress τ 0 Īllows standard Newtonian friction factor correlations to be used. For shear-dependent fluids, on the other hand, the viscosity varies. shear rate functionality of PP with different fraction of glass fibres at 230☌ is shown in Figure 4. The Herschel–Bulkley fluid is a generalized model of a non-Newtonian fluid, in which the strain experienced by the fluid is related to the stress in a complicated, non-linear way.

Apparent viscosity formula