[davparl]

Hi everyone,

I am running a two-way Fluent-Mechanical simulation of a shelf (100x3x200mm; xyz) immersed in a tank (300x500x300mm; xyz) filled with a liquid and a gas using VOF method. The tank is subject to the force of gravity and a harmonic force acting along the x-axis with a frequency f=2Hz. Since I wanted the liquid to be initialized with an angle of 10° I have created a region register with cylinder shape with the coordinates shown below. The other settings are shown below as well.
When I launch the analysis it stops at a certain time step for "Negative cell volume detected". I have tried to reduce the time-step but it stops even earlier in the simulation. Furthermore, looking at force report (from Fluent) and displacements report (from Mechanical) I have noticed that in the time step that leads to the error, the force and the displacements increase inexplicably and I am not understanding the reason if everything is going well until that time step. To visualize the cells with negative volume I have created a volume register and a iso-surface.

• Mesh of the shelf and a plane in the middle of the tank at t=0 https://ibb.co/61VVWmQ
• Mesh of a plane in the middle of the tank at t=0 https://ibb.co/zHTP3MW
• Register region settings https://ibb.co/89MXwBR
• Displacement of the shell at last time step https://ibb.co/1XwHhx0
• Iso-surface with negative volume cells and a plane along the tank at last time step https://ibb.co/T1FL5tm--> I think that the weird shape of the negative volume cells is due to the register region that I have created to patch the liquid region since it goes from the minimum coordinates and maximum coordinates that I have selected for the region register. I am not sure of this.
• Register region with tank and negative volume cells https://ibb.co/QJHVH6r
• Display of the shelf and negative volume cells at last time step pt.1 https://ibb.co/SsXFTCP
• Display of the shelf and negative volume cells al last time step pt.2 https://ibb.co/7RFsf1Q
• Dynamic Mesh Settings: Smoothing (Diffusion method with Diffusion Parameter: 1.5) and Remeshing (Unified Remeshing).

Can anyone point me a solution or a way to understand what is failing during the analysis?
Feel free to ask any other information that you may need. Thanks in advance.