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Say, we have bottled viscous liquid - such as a dishwashing liquid. There are two different caps for the bottle. One with a smaller hole, one with slightly bigger hole. Both holes are very small though.

Now, we invert the bottle with cap 1 on (smaller hole) then again with cap 2 (slightly bigger hole) .

Will the same liquid exhibit different (apparent viscosity) or same?

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  • $\begingroup$ How can we measure this viscosity looking at fluid flow? $\endgroup$ – Alex Trounev Jul 31 '19 at 14:07
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(What's apparent viscosity?)
The regular, diffusive viscosity, of dimension $m^2/s$ that appears in the Navier-Stokes equations divided by $\rho$, is mainly dependent on temperature in most newtonian fluids.

If your fluid is non-newtonian, then the viscosity is a function of stress, and it will change its value relative to how much it can relax, i.e. it is going to be a function of your hole diameter.

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