CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > FLUENT

Steady state Acoustic source contours

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

Reply
 
LinkBack Thread Tools Display Modes
Old   November 5, 2012, 00:31
Default Steady state Acoustic source contours
  #1
Member
 
Arun raj.S
Join Date: Jul 2011
Posts: 53
Rep Power: 5
arunraj is on a distinguished road
Hi all,

I am working on noise reduction in axial flow fan.. I am using FW-H acoustic model for noise prediction... It is an steady state analysis... But during post processing I am not able to find the acoustic source contours to understand from where the noise is actually generating... Is it possible to plot acoustic contours in steady state if I use Broadband noise model instead of FW-H.... It is really difficult to find how much contribution is there due to turbulence,tip vortex for fan noise generation with FW-H....
arunraj is offline   Reply With Quote

Old   November 5, 2012, 09:17
Question Error: Divergence detected in AMG solver: x-momentum.
  #2
New Member
 
Jaiganesh S
Join Date: Dec 2011
Posts: 8
Rep Power: 5
Jaiganesh S is on a distinguished road
Hi Mr. Arun raj,

I am doing Aeroacoustic analysis on aircraft wing using Ansys fluent. After 53 iterations, it getting error. I have mentioned that error below.

Error: Divergence detected in AMG solver: x-momentum.

I have described about my case below.
Pressure based, Transient.
LES Model.
Velocity Inlet , pressure outlet.
Scheme- PISO, neighbor correction - 1, Pressure - standard, momentum - Bounded central differencing, Transient formulation- First order Implicit, non iterative time advancement.
URF for Pressure - 0.001, for Momentum - 0.004.

And also I used Outflow as outlet instead of Pressure outlet. I changed neighbour correction & under relaxation factor. These Changes are not working.

Grid quality details:
Max. cell squish= 9.23091e-001.
Max. aspect ratio = 3.22832e+002.

Kindly help me to solve this problem. I am waiting for your kind response.

Thank you.
Jaiganesh S is offline   Reply With Quote

Old   November 5, 2012, 23:48
Default
  #3
Member
 
Arun raj.S
Join Date: Jul 2011
Posts: 53
Rep Power: 5
arunraj is on a distinguished road
Hi,

I havenot worked in transient simulation... But this error seems to be related to your boundary condition...check your boundary condition properly...
arunraj is offline   Reply With Quote

Old   November 7, 2012, 07:23
Default
  #4
New Member
 
Jaiganesh S
Join Date: Dec 2011
Posts: 8
Rep Power: 5
Jaiganesh S is on a distinguished road
Hi,
Thank you for your kind response. If i use hemi sphere domain instead of rectangular domain, will it solve x momentum error? what is the advantages of hemi sphere domain?

Kindly reply me. Thanks again.
Jaiganesh S is offline   Reply With Quote

Old   November 7, 2012, 07:30
Default
  #5
Member
 
Arun raj.S
Join Date: Jul 2011
Posts: 53
Rep Power: 5
arunraj is on a distinguished road
Hi,
I didnt anything related to your domain... It might be related to your mesh...check your mesh quality or bounday condition...I am doing acoustic analyis of axial flow fan...But I am not using any hemispherical domain...
arunraj is offline   Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
groovyBC in openFOAM-2.0 for parabolic velocity bc ofslcm OpenFOAM 22 August 26, 2013 11:06
friction forces icoFoam ofslcm OpenFOAM 3 April 7, 2012 10:57
Version 15 on Mac OS X gschaider OpenFOAM Installation 120 December 2, 2009 11:23
DecomposePar links against liblamso0 with OpenMPI jens_klostermann OpenFOAM Bugs 11 June 28, 2007 17:51
About the difference between steady and unsteady problems Lisa Main CFD Forum 11 July 5, 2000 14:37


All times are GMT -4. The time now is 21:08.