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Hi Vatslav,
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<div>Assuming your pipe is radius R, centered at x=y=0,</div>
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<div>then:</div>
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<div> rr = (x/R)**2 + (y/R)**2</div>
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<div> uz = 1-rr</div>
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<div>should work for axial.</div>
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<div> For the radial that you prescribe,</div>
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<div> ux = x ! = r cos theta = sqrt(rr)*(x/r) = x</div>
<div> uy = y</div>
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<div>Paul<br>
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<div id="divRpF687156" style="direction: ltr;"><font face="Tahoma" size="2" color="#000000"><b>From:</b> nek5000-users-bounces@lists.mcs.anl.gov [nek5000-users-bounces@lists.mcs.anl.gov] on behalf of nek5000-users@lists.mcs.anl.gov [nek5000-users@lists.mcs.anl.gov]<br>
<b>Sent:</b> Friday, November 11, 2016 1:54 AM<br>
<b>To:</b> nek5000-users@lists.mcs.anl.gov<br>
<b>Subject:</b> [Nek5000-users] Boundary condition on velocity<br>
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<div>Hi, neks.<br>
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I am trying to simulate a 3d pipe, fluid flows along z. And I need an inflow boundary condition on velocity on forming of cylinder.<br>
How I can set a radial velocity in userbc (Vr = sqrt( vx**2+vy**2 ) ) ? <br>
I need to set Vr and dVr/dr.<br>
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Thank you so mach<br>
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Vatslav<br>
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