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<div style="direction: ltr;font-family: Tahoma;color: #000000;font-size: 10pt;">Hi all,<br>
<br>
I am new to Nek5000, and am using the ALE capability in Nek500. I am trying to override the default way Nek5000 sets the mesh boundary conditions based on the fluid/thermal boundary conditions (section 5.7 in the PRENEK manual).<br>
<br>
On one boundary I have a Dirichlet velocity condition, 'v ', and on another I have an outflow condition, 'O '. On both these boundaries I would like to allow the mesh to move freely, without any constraint. At the moment Nek5000 either fixes the mesh or
allows the mesh nodes to slide freely in the tangential direction with a zero normal velocity.<br>
<br>
It seems that here <a href="https://github.com/Nek5000/Nek5000/blob/master/core/mvmesh.f#L41" target="_blank">
https://github.com/Nek5000/Nek5000/blob/master/core/mvmesh.f#L41</a> the mesh boundary conditions are set for the velocity boundary. Would the mesh be free to move in any direction on the velocity boundary if in mvmesh.f I change:<br>
<br>
IF (CBF(1:1).EQ.'V' .OR. CBF(1:1).EQ.'v' .OR.<br>
$ CBF(1:1).EQ.'W' ) THEN<br>
IFLD = 1<br>
CB = 'FIX'<br>
IF (IFMELT .OR. CBM.EQ.'+') CB='SYM'<br>
GOTO 200<br>
ENDIF<br>
<br>
to<br>
<br>
IF (CBF(1:1).EQ.'V' .OR. CBF(1:1).EQ.'v' .OR.<br>
$ CBF(1:1).EQ.'W' ) THEN<br>
IFLD = 1<br>
IF (IFMELT .OR. CBM.EQ.'+') CB='SYM'<br>
GOTO 200<br>
ENDIF<br>
<br>
?<br>
<br>
I did not notice an equivalent statement for the outflow condition 'O ' in mvmesh.f, is this set somewhere else?<br>
<br>
Any advice would be very much appreciated.<br>
<br>
Thanks very much,<br>
<div><br>
<div class="BodyFragment"><font size="2"><span style="font-size:10pt;">
<div class="PlainText">Louis Steytler<br>
Department of Mechanical Science and Engineering<br>
University of Illinois at Urbana-Champaign<br>
1206 West Green Street<br>
Urbana, Il 61801<br>
steytle1@illinois.edu </div>
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