I have a 3d cad model of a medical bellow which I am using to generate negative pressure (NP) to suck body fluids. What I am trying to do is to enhance the 3d model of the bellow so that I can rise the generated negative pressure by the bellow. The problem here is that I need a way to get the generated (NP) value AFTER changing the 3d model AND according to the material that I set for the part in the program. So I need a simulation program that can achieve these tasks.
Can you tell me if I can do this with Freecad or should I use a different program?
If it is possible with Freecad please refer me to related explanation videos or posts.
That’s a very interesting but also complex topic for engineering simulation if you want to account for both deformation of the bellow and airflow inside it. In such a case you will have to perform FSI (Fluid-Structure Interaction) simulation and FreeCAD can’t do it. You will likely have to perform a co-simulation using two programs - for CFD and for mechanical part. Personally, I’d recommend Abaqus and XFlow but there are also other possibilities.
In FreeCAD you could only simulate mechanical or CFD part of the problem individually but I don’t think that’s what you want to achieve at the moment.
Am I right to think that sucking is generated by the manual compression of the bellow? in other word, it depends on the internal volume of this part (which depends itself on the design, the material stiffness and so on). If so, I propose the following workaround:
to impose a displacement of the bellow
contact condition must be activated (the solver is non-linear)
to get the internal volume; you’ll need to calculate it outside freecad using Python for example
to bench results; the current design is your reference (the lowest the volume is, the lowest the NP wil be I guess)
Note that your design is axisymetrix, you’ve to use this feature; then the volume can be easily calculated using Guldin formula.
