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Hi Toon,
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<div>If you also have Walls, then v=0 at the all, and 0.1 at the other grid points. However, what</div>
<div>you have is a polynomial that is 0 at one point and 0.1 at the others... such a thing will be oscillatory.</div>
<div>(Similar to Gibbs phenomena for Fourier representation of a square wave.)</div>
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<div>Usually, we would have a boundary layer that smoothly transitions from a constant down to zero</div>
<div>at the wall.</div>
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<div>I usually do this with a polynomial fit that uses a polynomial order = (lx1-1)</div>
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<div>Paul</div>
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<div id="divRpF858542" 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> Tuesday, July 26, 2016 2:12 PM<br>
<b>To:</b> nek5000-users@lists.mcs.anl.gov<br>
<b>Subject:</b> [Nek5000-users] Velocity inlet boundary condition issue<br>
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<p>Dear users,</p>
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<p>I have a channel simulation where I set the boundary condition of one of the domain side as 'v' (in the box file). Then in the userbc subroutine, I define the velocity at that boundary as a constant (say 0.1). After I run my simulation and visualise the
result, the velocity at that boundary is not exactly the constant I put in the user file. Do you have any idea how this could happen?</p>
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<p>Thank you in advance.<br>
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<span style="font-size:11pt; font-family:Helvetica,Sans-Serif">Best regards,<br>
<br>
Toon</span><span style="font-family:'Trebuchet MS',sans-serif; font-size:11pt"><br style="font-family:'Trebuchet MS',sans-serif">
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