Modeling rheological behavior of bentonite suspensions as Casson and Robertson–Stiff fluids using Newtonian and true shear rates in Couette viscometry

摘要: Abstract The Casson model and the Robertson–Stiff have been used to determine whether they can describe rheology of aqueous bentonite suspensions. assessment utilized a total twelve sets experimental viscometric data from literature this work. Equations presented which allowed determination true shear rates experienced by fluids within gap rotational viscometer for both rheological models. Non-linear regression has applied two parameters three using Newtonian rates, are most often in analysis rheometric data. results showed that models well these suspensions with good statistical indicators. Furthermore, always higher than differences depend on particular suspension larger at low while become smaller indicating fluid behavior approaches rates. shapes rheograms remained essentially unchanged determined use very similar This was further confirmed computation approaches. For yield value computed were 7% plastic viscosity 3%. model, order 2 5% observed K -values, γ˙ 0 -values no n -values. These small differences, however, do not justify when analytical solutions exist allow without any compromise.