code_saturne User's Forum

Posted: **Thu Jun 01, 2023 4:14 pm**

Hi folks, I am running an ALE case, with a typical fluid init phase, and a restart for the mesh movement, but I encounter the following issue :

Code: Select all

 Start reading
 Reading dimensions complete
  Reading the previous time step number (restarting computation)  NTPABS =          500
  Reading the previous time step number (restarting computation)  TTPABS =   0.5000E+02
 Reading options complete
  Read variables from restart: restart/main.csc
 Reading complete

         READING THE AUXILIARY RESTART FILE             

 Start reading                                          
   Finished reading options                             
  restart/auxiliary.csc: section "ref_presstot01" not present.
@                                                            
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@                                                            
@ @@ WARNING: WHEN READING THE AUXILIARY RESTART FILE        
@    =======                                                 
@      Lecture des proprietes physiques                      
@                                                            
@    It was not possible to read some values from the        
@      auxiliary restart file.                               
@    They will be initialized by the default values.         
@                                                            
@     This situation can occur when the restart file         
@      originates from a run realised with different         
@      options or when the file is damaged.                  
@                                                            
@    The run will continue...                                
@                                                            
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@                                                            

   Fin de la lecture des proprietes physiques           
   Fin de la lecture du pas de temps                    
   Fin de la lecture des flux de masse                  
   Fin de la lecture des conditions aux limites         
  restart/auxiliary.csc: section "time_moments:sizes" not present.
   Fin de la lecture des donnees ALE                    
@                                                            
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@                                                            
@ @@ WARNING:       WHEN READING THE AUXILIARY RESTART FILE  
@    =======                                                 
@                                                            
@      The max number of structures NBMOMX supported by      
@        the writing format of the suite file is             
@        NFMTST =         99
@      There is here a greater number of structures          
@        NSTRMX =        200
@       If the effective number of structures is greater,    
@        these will not be reread.                           
@                                                            
@    The run will continue.                                  
@                                                            
@    Check the subroutine lecamx.                            
@                                                            
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@                                                            

   Fin de la lecture des donnees des structures ALE     
 End reading

I already tried changing the I/O writing and reading modes, and deactivated the parallel I/O too. Can anybody help me out ?. My mesh doesnt move at all.

Thanks by advance,

Here are some of my files :

Posted: **Fri Jun 02, 2023 3:31 pm**

Hello,

I checked the code, and this warning should not be an issue in practice. In v8.0, I expect the warning to have disappeared, as the 200 structure limit has been removed and the code changed a bit.

Same for the reference pressure point. I'll try to improve the logic to remove the warning, but using the default settings, it should remain at the same point for the restart, and have no impact.

Best regards,

Yvan

Posted: **Tue Jun 06, 2023 2:49 pm**

Hi Yvan, thanks for your answer, I understand it might only be a warning. Although i don't any explanations as to why my model doesnt move at all during the simulation. Do you have any idea why ? or do you know of any typical issues that may arise ?

The convergence tool doesnt even show anything for the mesh velocity.

Thanks by advance,

Posted: **Wed Jun 07, 2023 11:48 am**

Hello,

Do you have movement before the restart ? In that case there might be a bug.

Otherwise this may be due to BC's.

Best regards,

Yvan

Posted: **Wed Jun 07, 2023 12:01 pm**

Hi again, I don't have any movement before. I set a very simple case with an inlet, an outlet, a wall and symmetry conditions for the other sides of the box. ALE conditions are either all fixed or all sliding(I tried both ), with the wall being an internal coupling. I have set all my damping, mass, stiffness matrixes, and I tried having no initial mesh velocity aswell, still no luck.

I'm not very familiar with the ALE boundary conditions, so I'm trying to learn the subject. Is there a need for a least one sliding boundary ?

Posted: **Thu Jun 08, 2023 12:28 pm**

Hello,

Answering from my phone so I don't have the GUI before me to check, but I thi.k you need at least one coupled boundary.

I would guess that if ylu can acess the settings for stifffnes, damping lass, ... you have the correct boundary type (in v8.0 we movee that to the main BC définition so it is clearer).

I have only one test case with FSI. You can access it here https://github.com/code-saturne/saturne ... nteraction

You can compare that with your sertings (and check you have movement on the tutorial).

Best regards,

Yvan

Posted: **Fri Jun 09, 2023 10:28 am**

Thanks Yvan, I think my case isnt really possible within Code_Saturne. I would like to simulate the speed loss of a cylinde when entering water, I don't think Saturne's default tools can help me with it . I'll make a new post asking for opinions on the feasibility of said simulation.

You stay awesome, thanks for the fast answer !

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