# velocities exceeding critical value N 61

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April 20, 2022, 10:19
velocities exceeding critical value N 61
#1
New Member

shuqichang
Join Date: Feb 2022
Posts: 20
Rep Power: 3
Hello,
I always get an error at run time that is faster than N 61. I also tried to change some of the parameters, but nothing worked out. I hope you can help me solve it. Attached are my running file and STL file. Thank you for your help .
Attached Files
 file.zip (76.0 KB, 5 views)

 April 22, 2022, 08:44 #2 Super Moderator   Arun Kamath Join Date: Nov 2014 Location: Trondheim, Norway Posts: 175 Rep Power: 10 Some comments: You are attempting a 3D simulation with 2D boundary conditions. control.txt should have C12 and C 13 as 21 C 14 also 21. ctrl.txt I 12 1 N 40 3 N 47 0.1 Have you tried refining the grid, say to dx=0.5m? __________________ Arun Team REEF3D www.reef3d.com

April 22, 2022, 09:06
#3
New Member

shuqichang
Join Date: Feb 2022
Posts: 20
Rep Power: 3
Quote:
 Originally Posted by kamath Some comments: You are attempting a 3D simulation with 2D boundary conditions. control.txt should have C12 and C 13 as 21 C 14 also 21. ctrl.txt I 12 1 N 40 3 N 47 0.1 Have you tried refining the grid, say to dx=0.5m?
Hello，
I will make corrections according to your suggestions. But I removed X 24 after I asked the question, and it worked fine without the error of exceeding N 61. I'm not sure if the problem has anything to do with X 24.

 April 22, 2022, 10:07 #4 Super Moderator   Arun Kamath Join Date: Nov 2014 Location: Trondheim, Norway Posts: 175 Rep Power: 10 That is interesting. Are you sure then that the X 24 inputs you provide are correct? A wrong input for the moment of inertia can be a problem. OR The stl file may have two few triangles for representing the structure. This can be improved using the cad software you used to generate the stl file. __________________ Arun Team REEF3D www.reef3d.com