Calculation of resonant frequencies in empty bottle through FEA

Hello!

I need to solve the titled problem through numerical simulation/FEA. With resonant frequencies, I mean the modes that can be excited and heard when one by blows lightly across the mouth opening.

To start off I have created the geometry model of the air envelope as well as the surrounding wall in Solidworks. I have Matlab available to me through my University. Iam aware that the program Hyperworks would be able to do this, and been investigating this but my computer can simply not run HW (compatibility issues).

I am familiar with the PDE toolbox in Matlab and it's basic code operations for PDE (importGeometry, define boundary conditions etc.)and I have also watched tutorials and read helpfiles on the PDE problem setup. However in this particular case I would also need to define parameters such as bulk modulus (compressability) of air in the cavity, which I have not found available as a material property in Matlab.

So my concern is, I don't know if this type of simulation can be done in Matlab? I would appreciate any suggestions to this.

Best Regards

Marius

Answer 1

[Precise Simulation]

If you can export your geometry as STL CAD file, or alternatively create a Gmsh finite element mesh (from STEP, STL, or IGES format), then you can use the FEATool FEM simulation toolbox to model and simulate resonance frequencies with the Helmholtz equation as for example done here:

https://www.featool.com/model-showcase/07_classic_pde_03_resonance1