CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > REEF3D

Timestep synchronization between CFD_VTU and 6DOF_VTP groups

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 8, 2024, 08:00
Default Timestep synchronization between CFD_VTU and 6DOF_VTP groups
  #1
New Member
 
Stamatios Petalas
Join Date: Dec 2023
Posts: 10
Rep Power: 2
pe_sta is on a distinguished road
Hello,

I have the following problem during my testing:

I successfully run a configuration with a numerical wave tank, which has walls in all faces except the wave generation one. An .stl file was used to import a floating body, and the simulation run smoothly. The ctrl.txt file can be seen below.

When I import the pvtu group in paraview I realize that the time-steping is different from the vtp file that describes the floating object, so the two are out of sync during the animation.

I know that I can use a time synchronization filter in paraview to match the two, but my question is: how can I change this within the input file, so that data are written at the same timesteps?

Best,
Stamatis
pe_sta is offline   Reply With Quote

Old   February 8, 2024, 16:29
Default
  #2
New Member
 
Ahmet Soydan
Join Date: Jun 2015
Location: Trondheim, Norway
Posts: 25
Rep Power: 12
soydana is on a distinguished road
I can not see your ctrl file. Can you share it ?

Quote:
Originally Posted by pe_sta View Post
Hello,

I have the following problem during my testing:

I successfully run a configuration with a numerical wave tank, which has walls in all faces except the wave generation one. An .stl file was used to import a floating body, and the simulation run smoothly. The ctrl.txt file can be seen below.

When I import the pvtu group in paraview I realize that the time-steping is different from the vtp file that describes the floating object, so the two are out of sync during the animation.

I know that I can use a time synchronization filter in paraview to match the two, but my question is: how can I change this within the input file, so that data are written at the same timesteps?

Best,
Stamatis
__________________
Ahmet Soydan
Team REEF3D
www.reef3d.com
soydana is offline   Reply With Quote

Old   February 9, 2024, 05:52
Default
  #3
New Member
 
Stamatios Petalas
Join Date: Dec 2023
Posts: 10
Rep Power: 2
pe_sta is on a distinguished road
Yes, sorry, I forgot to attach the file. Here it is.
Stam
Attached Files
File Type: txt ctrl.txt (2.0 KB, 7 views)
pe_sta is offline   Reply With Quote

Old   February 9, 2024, 06:17
Default
  #4
New Member
 
Ahmet Soydan
Join Date: Jun 2015
Location: Trondheim, Norway
Posts: 25
Rep Power: 12
soydana is on a distinguished road
VTU and VTP printout files are supposed to be sync. Which version of REEF3D are you using?
Quote:
Originally Posted by pe_sta View Post
Yes, sorry, I forgot to attach the file. Here it is.
Stam
__________________
Ahmet Soydan
Team REEF3D
www.reef3d.com
soydana is offline   Reply With Quote

Old   February 10, 2024, 02:50
Default
  #5
New Member
 
Stamatios Petalas
Join Date: Dec 2023
Posts: 10
Rep Power: 2
pe_sta is on a distinguished road
Thank you Ahmet. I'm using version 23.11, so I guess this shouldn't be the problem..

In my case, the run has created 165 VTU files and 440 VTP files; I cannot find a logic relation between the two numbers.

Is there a way to force printout synchronization, or maybe manually set the time-step of VTP printout?
pe_sta is offline   Reply With Quote

Old   February 10, 2024, 03:50
Default
  #6
Member
 
Felix S.
Join Date: Feb 2021
Location: Germany, Braunschweig
Posts: 87
Rep Power: 6
Felix_Sp is on a distinguished road
Hey,


I think this is a bug related to P20 and P35. In all 6DOF files, there is a print flag:

Code:
if(((p->count%p->P20==0) && p->P30<0.0)  || (p->simtime>printtime && p->P30>0.0)   || (p->count==0 && p->P35==0))
P20 is initialized to be -10 if nothing else is given. Therefore, the printer prints for your P35 option AND for p->count%p->P20==0 so every tenth iteration.

I will forward this to the bug report channel, so there is a quick fix

For your application, why don't you use P 30 0.05 for the time being? Should result in the output you want.

Kind regards
Felix
Felix_Sp is offline   Reply With Quote

Old   February 10, 2024, 07:19
Default
  #7
New Member
 
Stamatios Petalas
Join Date: Dec 2023
Posts: 10
Rep Power: 2
pe_sta is on a distinguished road
This was very insightful Felix and good to know, thanks a lot.

Following your suggestion the synchronization problem was solved; VTU and VTP files are now printed at the same timestep.

Best,
Stamatis
pe_sta is offline   Reply With Quote

Reply


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



All times are GMT -4. The time now is 21:17.