Shear rate in the Couette viscometer with a narrow annular gap between cylinders. A new approximate formula

Abstract

For the narrow gap coaxial cylinder viscometer a new approximate formula is proposed $$\dot \gamma = f(\tau ) = - \beta ^2 \tau ^{\beta + 1} \int\limits_0^\tau {\Omega (t)t^{ - (\beta + 2)} } dt$$ whereβ = 2/(1 −s2).