[CIG-SHORT] Petsc linear solver not converging

[Birendra]

Thanks Brad. I agree. I am trying to create an unstructured grid with better aspect ratio. I will probably use 'bias' in cubit to get smaller cells near surface and coarser cells at depth.

Birendra 

> On Feb 27, 2015, at 10:17 AM, Brad Aagaard <baagaard at usgs.gov> wrote:
> 
> Birendra,
> 
> Another issue you need to keep in mind is the accuracy of the solution. Even if it converges, the regions with very poor aspect ratio may have much higher local errors. If the solution is very smooth, the high aspect ratios won't introduce much error. However, if the solution is not very smooth in the regions with the high aspect ratios, the errors could be significant. Once you get things to converge, you will likely need to iterate and adjust the mesh to resolve the solution accurately.
> 
> Cheers,
> Brad
> 
>> On 2/26/15 7:36 AM, Birendra jha wrote:
>> Brad,
>> 
>> Maximum aspect ratio is around 50. I know it's too large and I am working on a new grid. Is there anything I can do on the solver side?
>> 
>> Thanks
>> Birendra
>> --------------------------------------------
>> On Thu, 2/26/15, Brad Aagaard <baagaard at usgs.gov> wrote:
>> 
>>  Subject: Re: [CIG-SHORT] Petsc linear solver not converging
>>  To: cig-short at geodynamics.org
>>  Date: Thursday, February 26, 2015, 10:23 AM
>> 
>>  Birendra,
>> 
>>  Have you run the mesh quality
>>  checks? What is the maximum aspect ratio?
>> 
>>  Brad
>> 
>>  On
>>  2/26/15 7:04 AM, Birendra jha wrote:
>>  >
>>  Hi
>>  >
>>  > I am facing
>>  linear solver convergence issue while trying to run the
>>  attached test case. The only complexity in the problem is
>>  its unstructured grid, created to honor surface layers and
>>  two faults.
>>  >
>>  > I will
>>  appreciate any help in resolving this issue. I would like to
>>  avoid grid refinement.
>>  >
>>  > Thanks and regards
>>  >
>>  Birendra
>>  >
>>  >
>>  >
>>  >
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