I am unfamiliar with the FreeFEM and try to use it to solve the acoustic-elastic interaction problem.

The acoustic-elastic interaction problem is a coupling problem, where the exterior and interior domain are governed by the Helmholtz equation and Navier equation respectively. The exterior domain and interior domain are connected with a coupling conditon. Thus, we need to build two meshes to define the vector femspace for Navier equation and the scalar femspace space for Helmholtz equation. However, the error prints “Exec error : all the finites elements spaces must be defined on the same mesh in solve”.

I also didn’t find the example of the coupling problem defined on two meshes. So I wonder if such coupling problem could be solved by FreeFEM