Erik Kostson
Ansys Employee
PLease post them in-line like below:

As we said before to see the change in eigen-frequencies and response due to the flow in a pipe that is conveying fluid (so dynamic beam bending differential equation + Centripetal and Coriolis terms due to fluid flow) we just need a vibroacoustic (acoustic harmonic system ) analysis with structure (pipe) and fluid (water say), and we need to add the BF,ALL,VMEN,,, command to the acoustic nodes, for the mean flow in the acoustics - of course if the amplitudes are high and you have some nonlinear effects then this approach (vibroacoustic - linear theory) will not work.

Hope this helps:

So nonlinear vibrations (say high amplitudes) -> 2 way FSI (E.g., Fluent+Transient Structural Mechanical)
Linear vibrations (small amplitude vibrations) -> vibroacoustics.

All the best
PS:If you are using Fluent/CFD to mechanical coupling and why (due to nonlinear vibrations), then it is better to post under the fluids forum also.