how to find the shear rate equation from the velocity profile equation?
Physics and electronics discussion, revision, exam and homework help.
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how to find the shear rate equation from the velocity profile equation?I know the velocity profile equation (for laminar flow in a circular pipe) is:
uaverage = umax ((1 - r2)/R2)
and I know the shear rate= shear stress/viscosity
finding it difficult to relate the two?
The specific equation i'm dealing with is:
u = 9 [(1 - rr)/16]
Would appreciate any help :/Last edited by Sifr; 19-07-2012 at 18:56. -
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Re: how to find the shear rate equation from the velocity profile equation?http://en.wikipedia.org/wiki/Shear_stress
Look at "Shear stress in fluids". Shear stress is defined as the viscosity multiplied by the rate of change of the velocity in a direction perpendicular to its velocity. Verify in your head that this makes sense.
That equation should be all you need. For a fuller treatment see the Navier-Stokes equation.
