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Kamal,
<div><br>
</div>
<div>Have you looked at the peris example? The usr file there shows how to deform</div>
<div>a pipe geometry.</div>
<div><br>
</div>
<div>Paul</div>
<div><br>
<div style="font-family: Times New Roman; color: #000000; font-size: 16px">
<hr tabindex="-1">
<div id="divRpF449769" 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> Saturday, January 18, 2014 12:17 PM<br>
<b>To:</b> nek5000-users@lists.mcs.anl.gov<br>
<b>Subject:</b> Re: [Nek5000-users] Pipe with expansion<br>
</font><br>
</div>
<div></div>
<div>Dear Paul,
<div><br>
</div>
<div>I tried many ways to map my straight pipe geometry but it does not seem to work properly </div>
<div><br>
</div>
<div>I used something like </div>
<div><br>
</div>
<div>X = X + Z * tan ( alpha ) </div>
<div>Y = Y + Z* tan (alpha ) </div>
<div><br>
</div>
<div><br>
</div>
<div>even that dint work. could please help me with this </div>
<div><br>
</div>
<div>Thank you </div>
<div><br>
</div>
<div>Kamal.</div>
<div><br>
<div>
<div>On Jan 17, 2014, at 2:24 PM, <a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">
nek5000-users@lists.mcs.anl.gov</a> wrote:</div>
<br class="Apple-interchange-newline">
<blockquote type="cite">
<div bgcolor="#FFFFFF">Hi Paul, <br>
<br>
Thanks paul. I tried working with the diverging mesh modification.<br>
<br>
I tried to use this form of equation to modify the mesh <br>
<br>
z = mx + b<br>
z = ny + c <br>
<br>
x = ( z - b ) / m <br>
y = (z - c) / n<br>
<br>
Do you think would work ? or is there any other way to input that ?<br>
<br>
Thanks, <br>
<br>
Kamal<br>
<br>
<br>
<div class="moz-cite-prefix">On 17/01/2014 14:14, <a class="moz-txt-link-abbreviated" href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">
nek5000-users@lists.mcs.anl.gov</a> wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">Kamal,
<div><br>
</div>
<div>1) To check for convergence, run your simulation for increasing polynomial orders ( lx1 in the SIZE file) and measure some consistent quantity (drag, TKE, etc). You can plot this quantity against lx1 and this should give you a good picture of how you
are converging (without needing to change the physical mesh).</div>
<div><br>
</div>
<div>2) If you weren't using temperature in your simulation, you could do put the following code snippet in your userchk</div>
<div><br>
</div>
<div>c-------------------------------------------</div>
<div>integer i, ntot</div>
<div><br>
</div>
<div>ntot = nx1*ny1*nz1*nelv ! total number of points in simulation (on THIS processor)</div>
<div><br>
</div>
<div>do i = 1,ntot</div>
<div> t(i,1,1,1,1) = 0.5*(vx(i,1,1,1)**2 + vy(i,1,1,1)**2 + vz(i,1,1,1)**2)</div>
<div>enddo</div>
<div><br>
</div>
<div>ifto = .true.</div>
<div>c-------------------------------------------</div>
<div><br>
</div>
<div>I've assumed here that your density is unity. This computed kinetic energy point-wise and stores it in the temperature field. The part "ifto = .true." tells Nek to output the temperature field whenever it outputs a field file. You could then view this
in visit just like you would the velocity field.</div>
<div><br>
</div>
<div>Hope this helps!</div>
<div><br>
</div>
<div>Josh</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">On Wed, Jan 15, 2014 at 9:52 AM, <span dir="ltr"><<a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex; border-left:1px #ccc solid; padding-left:1ex">
Hi Paul,<br>
<br>
I will try that mapping, I created a straight pipe to do some simulations.<br>
<br>
1) Is there a way to check my spectral convergence, so that I can do some mesh convergence study?<br>
2) Is there a way to plot the kinetic energy in the flow ?<br>
<br>
Thank you,<br>
Kamal
<div class="HOEnZb">
<div class="h5"><br>
<br>
<br>
<br>
On 15/01/2014 12:14, <a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">
nek5000-users@lists.mcs.anl.gov</a> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex; border-left:1px #ccc solid; padding-left:1ex">
<br>
Hi Kamal,<br>
<br>
For the geometry you describe, I would apply mesh morphing<br>
to a standard straight pipe. You can create such a pipe<br>
using a subset of the mkmesh script provided in the expansion<br>
example.<br>
<br>
If your transition region is conical, then I woud make<br>
certain that the change in slope occurs at element boundaries,<br>
i.e., as in the half cross-section depicted below:<br>
<br>
_______________<br>
/| | |<br>
/ | | |<br>
/| | | |<br>
________________/ | | | |<br>
| | | | | | | |<br>
| | | | | | | |<br>
+-----+-----+---+--+---+------+------+----> z<br>
<br>
<br>
Paul<br>
<br>
<br>
<br>
On Wed, 15 Jan 2014, <a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">
nek5000-users@lists.mcs.anl.gov</a> wrote:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex; border-left:1px #ccc solid; padding-left:1ex">
Hi Paul,<br>
<br>
I looked at the example and it looks very helpful, but for a sudden expansion we have only two parts (i.e) the inlet pipe and the outlet pipe. Whereas in a diverging pipe we have three section (i.e,) The inlet pipe, Diverging section and the outlet pipe.<br>
<br>
<br>
Is it possible for me to create a 2D diverging section using mesh modification and revolve it around the centre axis to get a 3d diverging pipe ?<br>
<br>
<br>
or should I apply the mesh modification directly to the 3d sudden expansion pipe using usrdat2() ?<br>
<br>
Thanks,<br>
Kamal<br>
<br>
<br>
On 14/01/2014 21:09, <a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">
nek5000-users@lists.mcs.anl.gov</a> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex; border-left:1px #ccc solid; padding-left:1ex">
Hi Paul,<br>
<br>
Thanks a lot for the update. I will take a look at as soon as possible and keep you updated with it.<br>
<br>
Thank you,<br>
<br>
Kamal<br>
<br>
On Jan 14, 2014, at 9:04 PM, <a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">
nek5000-users@lists.mcs.anl.gov</a> wrote:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0
0 .8ex; border-left:1px #ccc
solid; padding-left:1ex">
Kamal,<br>
<br>
I've added an example for a step-type expansion in a pipe. New example directory<br>
is nek5_svn/examples/expansion, with a README.<br>
<br>
If you want a standard diffuser, I would use mesh-morphing, as outlined in the<br>
nek primer, which can be found on this page:<br>
<br>
<a href="http://nek5000.mcs.anl.gov/index.php/UG#Documentation" target="_blank">http://nek5000.mcs.anl.gov/index.php/UG#Documentation</a><br>
<br>
I've also automated our turbulent outflow bc treatment -- one simply provides an<br>
expansion factor (typically ~ 1.5) and two persistent arrays to turb_outflow(), which<br>
is now in navier5.f. This can be useful when very strong vortices are leaving the<br>
domain, which is possible for certain diffuser flow conditions (and others).<br>
<br>
Paul<br>
________________________________________<br>
From: <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>
Sent: Monday, January 13, 2014 3:35 AM<br>
To: <a href="mailto:nek5000-users@lists.mcs.anl.gov" target="_blank">nek5000-users@lists.mcs.anl.gov</a><br>
Subject: [Nek5000-users] Creating a Mesh<br>
<br>
Hi<br>
<br>
Can some one please help me in this because I am new to nek<br>
<br>
1) How can I create a .rea for a specific geometry say ' A sudden<br>
expansion pipe ' or a ' Diverging pipe '<br>
<br>
2) What tool I should use to create that mesh.<br>
<br>
<br>
Thank you<br>
<br>
<br>
kamal<br>
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