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-   -   Steady state Acoustic source contours (http://www.cfd-online.com/Forums/fluent/108913-steady-state-acoustic-source-contours.html)

arunraj November 5, 2012 00:31

Steady state Acoustic source contours
 
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....

Jaiganesh S November 5, 2012 09:17

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

arunraj November 5, 2012 23:48

Hi,

I havenot worked in transient simulation... But this error seems to be related to your boundary condition...check your boundary condition properly...

Jaiganesh S November 7, 2012 07:23

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.

arunraj November 7, 2012 07:30

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...


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