= Inertialess Oldroyd-B circular Couette pressure
{title2=$p=p_0+2(\mu-\mu_r)\tau B^2/r^4$}
For circular <Couette flow> with $v=Ar+B/r$, the <rotating-frame reduction of circular viscoelastic shear> gives shear rate $g=-2B/r^2$. The total <shear stress> is $\mu g$, and the azimuthal minus radial <normal-stress difference> is $2(\mu-\mu_r)\tau g^2$ in the stress convention where $\sigma_{rr}=-p$. Radial <force balance> without inertia is $p'=-2(\mu-\mu_r)\tau g^2/r$, which integrates to the displayed pressure. The pressure constant is undetermined by these equations.
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