[Jack80]

Hi.

I haver recently installed the foam-extend-4.0 to perform a fsi analysis.

I have run a simulation of a liquid flowing over a flat plate with constant speed using the 3dtube tutorial.

I have modeled 2 bodies, the blue one is called agua (liquid) its dimensions are 1m x 0.2m x 0.002 m, and the orange one is called niquel (solid) with dimensions 1m x 0.2 m x 0.001 m.

The liquid boundaries are as follow:

- Inlet (0.2m x 0.002m)

- Outlet (0.2m x 0.002m)

- agua (region in contact with the solid, face-zone name is agua-zone)

- pared-agua (the rest of the walls).


The solid boundaries are as follow:

- niquel (region in contact with the fluid, face-zone name is niquel-zone)

- niquel externo (top face of the solid)

- pared-fija (the side walls of the solid).

I'm using weakFsiFoam as a solver (fsiFoam solver also works, but is way too slow).


The results show that the maximum displacement is below 1e-8 meters, which can't be right. The pressure in the fluid domain is too low (below 10 Pa, but I'm not 100% sure if the pressure shown is not in fact P/rho).


I'm also not sure what DD and pointDD files which can be found in some tutorials are for.

And last, I can see that in every time step a new polymesh is generated for region fluid, but I can't find a polymesh generated for the solid. Is there any file with the new solid mesh generated, or I should use the pointD file generated and modify manually the solid mesh?

I have attached my case. The blockMesh file is in the constant/polyMesh folder and the facezones file is in the fluid or solid folder.


Any help or advice you can provide me will be appreciated.

[HosseinB]

Originally Posted by Jack80

Hi.

I haver recently installed the foam-extend-4.0 to perform a fsi analysis.

I have run a simulation of a liquid flowing over a flat plate with constant speed using the 3dtube tutorial.

I have modeled 2 bodies, the blue one is called agua (liquid) its dimensions are 1m x 0.2m x 0.002 m, and the orange one is called niquel (solid) with dimensions 1m x 0.2 m x 0.001 m.

The liquid boundaries are as follow:

- Inlet (0.2m x 0.002m)

- Outlet (0.2m x 0.002m)

- agua (region in contact with the solid, face-zone name is agua-zone)

- pared-agua (the rest of the walls).


The solid boundaries are as follow:

- niquel (region in contact with the fluid, face-zone name is niquel-zone)

- niquel externo (top face of the solid)

- pared-fija (the side walls of the solid).

I'm using weakFsiFoam as a solver (fsiFoam solver also works, but is way too slow).


The results show that the maximum displacement is below 1e-8 meters, which can't be right. The pressure in the fluid domain is too low (below 10 Pa, but I'm not 100% sure if the pressure shown is not in fact P/rho).


I'm also not sure what DD and pointDD files which can be found in some tutorials are for.

And last, I can see that in every time step a new polymesh is generated for region fluid, but I can't find a polymesh generated for the solid. Is there any file with the new solid mesh generated, or I should use the pointD file generated and modify manually the solid mesh?

I have attached my case. The blockMesh file is in the constant/polyMesh folder and the facezones file is in the fluid or solid folder.



Any help or advice you can provide me will be appreciated.

I am trying to understand fsiFoam and running some test simulations.



Hi Jack, Did you find out what DD and pointDD are? Do they have to be included in the set-up files?



By the way, since there is no gravity in the model, why do you expect to have a larger displacement?



Your steel density was 12000!


Cheers,
Hossein

[Hgholami]

Hi.
For your first question.
The DD and PointDD are "Differential Displacement" and "Point Differential Displacement", respectively. These variable are uses in Incremental total Lagrangian. When you use unsIncrTotalLagrangianSolid solver for solid in fsiFoam, you need two files.