Perfectly Matched Layers (PMLs)
Care should be taken when setting up perfectly matched layers (PMLs) in multiphysics models where different waves propagate. A discussion about the Acoustic-Structure interaction situation is given in Configuration of Perfectly Matched Layers (PMLs) for Acoustic–Structure Interaction Models in Modeling with the Acoustic–Structure Interaction Branch. The approach described is valid in general for models where several sound speeds are present.