Power Law rheology – Audit
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Power Law rheology model calculations, release 1a, issued 8 October 2008.
This worksheet takes Fann viscometer readings at 300rpm and 600 rpm. It outputs values of n and K for the Power Law model and plots a graph of Shear Stress against Shear Rate.
Fann 300 rpm dial reading, lb/100ft2
Fann 600 rpm dial reading, lb/100ft2
Fann viscometer 300 rpm reading
Fann viscometer 600 rpm reading
Calculate n and K
If n = 1, the fluid is Newtonian.
If n > 1, the fluid is Dilatent.
If n < 1, the fluid is non-Newtonian (most muds).
Shear stress Pστ = KΓn
Plot shear stress (Pστ) vs shear rate (Γ)
Click here when any values are modified to update the result.
Version 1 of this worksheet was released on 7 October 2008 by Steve Devereux.