Hey everyone,
I am setting up an FSI simulation between OpenFOAM and Abaqus. In the future I will have the setup running on a Linux based HPC. For now, I am running OpenFOAM and preCICE on WSL and Abaqus on Windows.
As there is no official Abaqus Adapter at the time being (maybe there is by now? ) I am writing two subroutines to link Abaqus to preCICE. UEXTERNALDB for file exchange and DLOAD (distributed load) to apply the loads from OpenFOAM to Abaqus. OpenFOAM sends the pressure values to preCICE/Abaqus and Abaqus sends the displacements back to the Fluid-Mesh.
Now concerning my question: To my knowledge preCICE calculates the loads at the element’s nodes. However, the DLOAD subroutine “will be called at each load integration point…”. Is this a potential issue for my simulation? Is there anything specific I need to be taking into account in this case?
Another question I have is about the data that the OpenFOAM Adapter can write. As mentioned above, I want to transfer the fluid pressure to the structure. Do I have to write the stresses and derive the pressure from them? I would appreciate some clarification on this matter.
These closed-source adapters are tricky for us to develop and maintain. However, these companies are often aware of preCICE and are waiting for customer demand to build adapters. If you are a customer, let them know!
preCICE follows the black-box approach, meaning that it has no concept of solver internals such as integration points. It only cares about point clouds and the data that is assigned to these points.
Therefore, you are free to choose what these meshes represent as long as the participants of your simulation have a common or compatible understanding of how to handle these meshes and data.
For this, I hand over to @Makis, who has a better understanding of recent developments.
I understand that with “preCICE” here you mean “the OpenFOAM-preCICE adapter”. Indeed, the OpenFOAM adapter writes stresses (and forces) at the face centers, see:
I have a documentation PR clarifying what is supported where, I will tend to it in the next days.
By “fluid pressure”, I would understand you want what the adapter calls “stress”:
There is a variant of the perpendicular-flap tutorial using stresses:
If you manage to couple with Abaqus, this would be a really helpful addition to that tutorial!
Maybe we should bring together everyone interested coupling Abaqus (us included) and lock them into a room with pizza and beer until code comes out…
Hey, thanks to the both of you, everything answered!
Once I have a working solution (fingers crossed), I will happily share with you. But it will take a couple of months for me to be finished, so there might be some more questions coming in this thread.
Until then take care and maybe see you in a room full of pizza and beer
) I am writing two subroutines to link Abaqus to preCICE. UEXTERNALDB for file exchange and DLOAD (distributed load) to apply the loads from OpenFOAM to Abaqus. OpenFOAM sends the pressure values to preCICE/Abaqus and Abaqus sends the displacements back to the Fluid-Mesh.
