Sweep shear rate over a specimen, fit Newtonian, power-law and Herschel-Bulkley models to the resulting flow curve, and read the residual plot that tells you whether the fit is trustworthy.
This instrument implements the three flow models from Module 2 and is the tool Module 10 asks you to use for model fitting. Choose a specimen, choose a model to fit to it, and drag the shear-rate cursor to read the flow curve and viscosity curve at a point. The fit updates live; the residual plot below the curves is what tells you whether the model you picked actually describes the specimen, independently of the R² number.
Apparatus — parallel-plate rheometerThe instrument, not the specimen. A thin disc of material sheared between two plates is how every flow curve on this site was (synthetically) generated.
Flow curve — shear stress τ (Pa) vs shear rate γ̇ (s⁻¹), log–logViscosity curve — apparent viscosity η (Pa·s) vs shear rate γ̇ (s⁻¹), log–logResidual plot — measured minus fitted stress (Pa) vs shear rate γ̇ (s⁻¹, log axis)
Measured (synthetic) sweep point
Fitted model curve
Shear-rate cursor
Residual: model overpredicts
Residual: model underpredicts
Fitted parameters
References
Steffe, J.F. (1996). Rheological Methods in Food Process Engineering, 2nd ed. Freeman Press.
Walstra, P. (2003). Physical Chemistry of Foods. Marcel Dekker.