[sagi shahar]

Hello everyone,
I am trying to create a fluent simulation for free falling of flat plate in-water. The plate falls between a guide box walls that are located very close to it (gap of 0.5-2 mm) and allows the plate to move only on the vertical direction.
The problem occurs when I run the simulation.
It stops at the beginning and shows me the massage: "Negative cell volume detected".
Attached a document with print screens of the settings that I set for the simulation. The pictures are pretty unclear because I had to compress the file, so if you don't understand it I would like to send you the original file.
I will be happy if someone here will be able to help me, because I've tried to solve it in many ways and I didn't succeed yet.

Thank you,
Sagi

[maccheese]

Did you try "display zone motion" and "preview mesh motion" in the dynamic mesh settings? With these functions you can get a good overview on which time step size is required for the remeshing to work properly.


I have faced the same problem and in my case I had to choose a smaller time step so the mesh doesn´t fold.

[Blue]

Originally Posted by sagi shahar

Hello everyone,
I am trying to create a fluent simulation for free falling of flat plate in-water. The plate falls between a guide box walls that are located very close to it (gap of 0.5-2 mm) and allows the plate to move only on the vertical direction.
The problem occurs when I run the simulation.
It stops at the beginning and shows me the massage: "Negative cell volume detected".
Attached a document with print screens of the settings that I set for the simulation. The pictures are pretty unclear because I had to compress the file, so if you don't understand it I would like to send you the original file.
I will be happy if someone here will be able to help me, because I've tried to solve it in many ways and I didn't succeed yet.

Thank you,
Sagi

Use tetrahedral mesh and small time-step. See the previous discussion on this website.