Erik Kostson
Ansys Employee
to further clarify.

Ansys in general does not have an equivalent MFLUID like capability to account for the fluid added mass.
(as a side Aqwa is not suitable for doing what you need (investigate the vibration of submerged structures))

They way to do what you describe with an Ansys product, is to use Ansys Workbench (Mechanical Modal Acoustics or Harmonic Acoustics) which can account for the fluid added mass. This is done in practice by modelling and meshing the water with acoustic elements (FLUID220/FUID221 and FLUID30), which are then connected with the structural elements (say of a submerged steel structure). For more info on this approach search the forum for fluid added mass (I have written a few times about this and you should see how this is done in practice).
As I said this is not similar to the mfluid approach as we use acoustic elements to represent the actual fluid and the fluid added mass on to a structure, but it is the way we can do this. Hope you still find this info. useful.