Coupled Mechanic-Acoustic Eigenvalues in a Fluid Filled Pipe
We consider a fluid filled pipe in an axi-symmetric setting. Three eigenvalue analyses are done, first for the individual problems (fluid only, pipe only) and then for the coupled case.
- Look at the geometry definition in the Trelis journal file
- Go through the simulation input
mech-acou-eigenvalues.xml. The material file
mat.xmlis pretty standard
- Run the simulation using the run-script
- Look at the mode shapes for the different sequence steps. You can use the provided paraview state file
Things to think about
- How could you estimate the first fluid-only mode analytically?
- What does the mode shape and natural frequency of the pipe only represent? What do the natural frequencies depend on?
- Why are the natural frequencies of the coupled system lower?
- Can you estimate the wave speed of a compression wave in the pipe?