<div dir="ltr">Hi Aleks, following your advice, it works. Thank you very much!<div><br></div><div>Wei</div><div class="gmail_extra"><br><div class="gmail_quote">2014-11-06 12:31 GMT+01:00 <span dir="ltr"><<a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div>
<div style="direction:ltr;font-family:Tahoma;color:#000000;font-size:12pt">P.S. Sorry, correction -- I meant you should increase your p22 from 1e-16 to. say 1.e-12 but you will also need to keep p21 at least 1 or 2 order of magnitude higher, say 1.e-10<br>
<br>
Aleks<br>
<div style="font-family:Times New Roman;color:#000000;font-size:16px">
<hr>
<div style="direction:ltr"><font color="#000000" face="Tahoma"><span class=""><b>From:</b> <a href="mailto:nek5000-users-bounces@lists.mcs.anl.gov" target="_blank">nek5000-users-bounces@lists.mcs.anl.gov</a> [<a href="mailto:nek5000-users-bounces@lists.mcs.anl.gov" target="_blank">nek5000-users-bounces@lists.mcs.anl.gov</a>] on behalf of <a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a> [<a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a>]<br>
</span><b>Sent:</b> Thursday, November 06, 2014 5:28 AM<br>
<b>To:</b> <a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a><br>
<b>Subject:</b> Re: [Nek5000-users] **ERROR**: Failed in HMHOLTZ<br>
</font><br>
</div><div><div class="h5">
<div></div>
<div>
<div style="direction:ltr;font-family:Tahoma;color:#000000;font-size:12pt">Hi Wei,<br>
<br>
Your Helmholtz tolerance of 1e-16 is too high (p22) -- velocity components start an interation from 5...4.e-2 residuals and converge to 4...2.e-16.<br>
<br>
Once you lower it, make sure the Divergence tolerance (p21) is still an order or 2 magnitude higher.<br>
<br>
Aleks <br>
<div style="font-family:Times New Roman;color:#000000;font-size:16px">
<hr>
<div style="direction:ltr"><font color="#000000" face="Tahoma"><b>From:</b> <a href="mailto:nek5000-users-bounces@lists.mcs.anl.gov" target="_blank">nek5000-users-bounces@lists.mcs.anl.gov</a> [<a href="mailto:nek5000-users-bounces@lists.mcs.anl.gov" target="_blank">nek5000-users-bounces@lists.mcs.anl.gov</a>] on behalf of <a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a> [<a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a>]<br>
<b>Sent:</b> Thursday, November 06, 2014 5:21 AM<br>
<b>To:</b> <a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a><br>
<b>Subject:</b> [Nek5000-users] **ERROR**: Failed in HMHOLTZ<br>
</font><br>
</div>
<div></div>
<div>
<div dir="ltr">
<div class="gmail_extra"><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px">Hi Neks</span>
<div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px"><br>
</div>
<div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px">when I setup a profile 2D flow, there are informations like this, but the simulation is not crash,</div>
<div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px"><br>
</div>
<div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px">
<div style="margin:0px;font-size:18px;font-family:'Andale Mono';color:rgb(41,249,20);background-color:rgb(0,0,0)">
<div style="margin:0px">Step 800, t= 8.0000000E-02, DT= 1.0000000E-04, C= 0.431 9.2444E+03 1.0117E+01</div>
<div style="margin:0px"> Solving for fluid F T T</div>
<div style="margin:0px"> 800 100 **ERROR**: Failed in HMHOLTZ: VELX 3.7727E-16 5.3129E-02 1.0000E-16</div>
<div style="margin:0px"> 800 100 **ERROR**: Failed in HMHOLTZ: VELY 2.4683E-16 3.5181E-02 1.0000E-16</div>
<div style="margin:0px"> 800 U-PRES gmres: 23 5.6827E-15 1.0000E-14 9.6473E-07 9.5640E-01 2.4052E+00</div>
<div style="margin:0px"> 800 8.0000E-02 1.0044E+01 Fluid done</div>
<div style="margin:0px"> 800 8.00000000000E-02 6.70022578679E-01 1.99103625323E-01 4.70918953356E-01 1dragx</div>
<div style="margin:0px"> 800 8.00000000000E-02 4.12612202513E-01 5.10664067531E-01 -9.80518650173E-02 1dragy</div>
<div style="margin:0px"> dump history points</div>
<div style="margin:0px"> done :: dump history points</div>
<div><br>
</div>
</div>
<div><br>
</div>
<div>The CFL number is below than 0.5 already, the polynomial order is 7 in this case. when I choose a lower order p, this information will be disappeared after several iteration steps. I have checked the mesh looks fine, the parameters setting are copied
from “ext_cyl” with a smaller values of p21 to p25, I don’t know what is wrong, should I ignore ?</div>
</div>
<div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px"><br>
</div>
<div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px">thanks,</div>
<div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px"><br>
</div>
<div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px">Wei</div>
<div><br>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div></div></div>
</div>
</div>
<br>_______________________________________________<br>
Nek5000-users mailing list<br>
<a href="mailto:Nek5000-users@lists.mcs.anl.gov">Nek5000-users@lists.mcs.anl.gov</a><br>
<a href="https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users" target="_blank">https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users</a><br>
<br></blockquote></div><br>
</div></div>