Shear rate equations for yield stress fluids in couette flow

Main Article Content

Y.K. Leong

Abstract

The accuracy of the Krieger-Maron, power law and Yang-Krieger equations for calculating the shear rate of three specific Herschel-Bulkley fluids (r = + Kr) couette flow within the annulus of a concentric cylinder was assessed. The chosen fluids have a shear rate exponent n of 1, 1/2 and 1/3. The accuracy for all three equations was found to depend upon the fluid model, stress level and radius or gap ratio E of the concentric cylinders. With the Krieger-Maron equation, the shear rate is only accurate in the fully sheared regime for all n and E. In contrast both the power law and Yang-Krieger equations are accurate in both the plug and fully sheared flow regimes. For both equations, the largest absolute error generally decreases with increasing E and decreasing n and is usually located near the transition from plug to fully sheared flow. In terms of the largest absolute error, the Yang-Krieger is more accurate

Downloads

Download data is not yet available.

Article Details

How to Cite
Leong, Y. (1999). Shear rate equations for yield stress fluids in couette flow. Malaysian Journal of Science, 18(1), 91–97. Retrieved from https://mjes.um.edu.my/index.php/MJS/article/view/9396
Section
Original Articles