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Problem in Global Equations defined variable
Posted 7 avr. 2014, 19:43 UTC−4 Structural Mechanics 2 Replies
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Hi all,
Does anybody know how to fix this? I am simulating a cavity filled with incompressible fluid under external pressure. Following the COMSOL Blog: www.comsol.com/blogs/computing-controlling-volume-cavity/, I used the global equations to define a pressure load "Inner_pressure" to the inner wall of a cavity beam. The global equation is set to find out whatever value of "Inner_pressure" only if it can satisfy the constraint that the cavity's volume is always the same to undeformed state. I tried this method in 2D successfully, but in 3D it has a error like this.
****************************************
Failed to find a solution.
Singular matrix.
There are 1 void equations (empty rows in matrix) for the variable comp1.Inner_pressure.
at coordinates: (0,0,0), ...
Returned solution is not converged.
****************************************
Does anybody know how to fix this? I am simulating a cavity filled with incompressible fluid under external pressure. Following the COMSOL Blog: www.comsol.com/blogs/computing-controlling-volume-cavity/, I used the global equations to define a pressure load "Inner_pressure" to the inner wall of a cavity beam. The global equation is set to find out whatever value of "Inner_pressure" only if it can satisfy the constraint that the cavity's volume is always the same to undeformed state. I tried this method in 2D successfully, but in 3D it has a error like this.
****************************************
Failed to find a solution.
Singular matrix.
There are 1 void equations (empty rows in matrix) for the variable comp1.Inner_pressure.
at coordinates: (0,0,0), ...
Returned solution is not converged.
****************************************
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2 Replies Last Post 27 juin 2017, 14:46 UTC−4
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Posted:
1 decade ago
Hi,
In order to compute the volume using the technique from the blog post, the study must be geometrically nonlinear. It is only then that the spatial coordinates reflect the deformed configuration.
Regards,
Henrik
In order to compute the volume using the technique from the blog post, the study must be geometrically nonlinear. It is only then that the spatial coordinates reflect the deformed configuration.
Regards,
Henrik
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Posted:
7 years ago
Updated:
7 years ago
Link above is "broken" since it includes comma
Working link is below
www.comsol.com/blogs/computing-controlling-volume-cavity/
Working link is below
www.comsol.com/blogs/computing-controlling-volume-cavity/