CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

pisoFOAM - internal pipe flow - convergence

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 18, 2017, 13:12
Default pisoFOAM - internal pipe flow - convergence
  #1
gu1
Senior Member
 
Guilherme
Join Date: Apr 2017
Posts: 231
Rep Power: 10
gu1 is on a distinguished road
Hello,

First, I'm using OpenFOAM 5.0 (komegaSST), the mesh is attached below as well as the link to Dropbox, where you can see all my settings.

Re = 5300 (R = 0,006035 - L=5D)
DROPBOX

I believe my settings are ''good'', but they can improve and I need your help for this.
Inside the file there are two images related to RESIDUAL. With a shorter timeStep I was able to converge faster, but to certain extent (300 iterations), then tend to behave steadily ... I would like to improve performance, because according to bibliographical references it was possible the convergence with 1200 iterations (if not verified in my configurations).

And a question that arises is with respect to the Courant number, for deltaT = 1e-4 the value is around 0.1, while for deltaT-1e-6 this value drops significantly (Co = 0.01). Would it be necessary to have such a low Co to accelerate convergence?

Quote:
yPlus yPlus write:
writing object yPlus
patch pipe y+ : min = 0.0264039, max = 0.0322391, average = 0.0302202
For this reason (y + ~ 1) and according Tobi, I set my settings:

Quote:
-boundary conditions for walls:
U=(0,0,0), p=zeroGradient, k=1e-15, omega=omegaWallFunction, nut=calculated
to eliminate the wall conditions. Did I execute correctly?

... and, according to my settings, I set the internal velocity to be 1 m/s (because it is a cyclic domain, there is a need for a fvOption file). This velocity was not constant throughout the iterations, reducing it. This is normal?

Thanks
Attached Images
File Type: jpg mesh.jpg (105.2 KB, 14 views)

Last edited by gu1; December 20, 2017 at 13:12.
gu1 is offline   Reply With Quote

Reply

Tags
komegasst, openfoam, pisofoam, wallfunction

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Laminar Pipe Flow convergence issues preichl OpenFOAM Running, Solving & CFD 11 September 22, 2014 21:22
Internal Flow Not Enough Turbulent - (pisoFoam, LES, sub grid models) vut OpenFOAM Running, Solving & CFD 5 September 15, 2014 14:18
modeling a pipe with both internal and external flow amir_14 FLUENT 4 July 9, 2014 17:18
[snappyHexMesh] Pipe flow / Internal fluid dynamics with SnappyHexMesh denner OpenFOAM Meshing & Mesh Conversion 3 October 13, 2011 09:24
Disturbed flow field at outlet boundary (Multiphase flow through pipe) Michiel CFX 17 April 21, 2010 10:14


All times are GMT -4. The time now is 06:54.