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stefanos January 19, 2013 10:23

Negative-cell volume error for water entry problem
Dear community,

I am trying to simulate a steady velocity motion for a 2D cylinder water-entry problem by using the VOF method in Fluent 13.0. I have already checked the functionality of VOF method within Fluenr for free-surface modeling, by solving a steady-state case.

Thus, now i am using a DEFINE_CG_MOTION UDF with a steady vertical velocity for the solid boundary motion. Due to the quad mesh i use the Smoothing and Layering options for the deforming mesh. Next, i assign the rigid body motion at the moving wall and at a moving fluid zone outside the wall which includes the boundary layer, while the deforming zone is set at the surrounding fluid.

However i get the "Negative-cell volume" detection error.

I have also noticed that at the Dynamic Mesh Zones panel there are more than one zones referred to only one, e.g., for the deforming fluid there is a zone "fluid" and a zone "interior-fluid" as well. I have tried to solve by assigning the deforming zone option at only one of the two labels and at both labels, as well and, at all cases, the negative-cell volume problem remains.

I would be very thankful if someone gave me an idea for facing this problem.


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