[Nek5000-users] Integral on the wall

[nek5000-users at lists.mcs.anl.gov]

Dear Valerio,


You would need to modify torque calc to do this,

assuming that your objective is to compute a line

integral of the pressure on the GLL points.


Assuming that your pipe mesh was made by

sweeping the geometry in the z direction with

n2to3, the modification should be quite easy.


The routine I would start with would be drgtrq

in navier5.f, which I see uses the two-index

loop to traverse faces based on jskip1 and jskip2.


For your case, I would use the facind() 3 index

loop approach (e.g., as used in norcmp2 routine).


Then you track the outer "k" loop and accumulate one

value for each k value and for each z level of the elements.

You will know the z level because it will be:


   klevel_e = 1 + (eg-1)/nelxy


where nelxy is the number of elements in your pipe

cross section.


Hopefully this will get you pointed in the right direction...


Best,

Paul




________________________________
From: Nek5000-users <nek5000-users-bounces at lists.mcs.anl.gov> on behalf of nek5000-users at lists.mcs.anl.gov <nek5000-users at lists.mcs.anl.gov>
Sent: Wednesday, May 9, 2018 3:13:19 AM
To: nek5000-users at lists.mcs.anl.gov
Subject: [Nek5000-users] Integral on the wall


Dear all,

I want to compute the integral of the pressure on pipe wall at different cross-sections. I tried using the routine set_obj, setting as many objects as the number of elements along the pipe length and then using the routine torque_calc. However I would like to compute it on each circumference where GLL nodes are defined, for example if I use lx1 = 8 I would like to compute it on 8 cross-sections per element. Is there an efficient way to do this using the set_obj routine?


Thanks. Best regards.

Valerio
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/nek5000-users/attachments/20180509/961eccb9/attachment.html>