Structural and acoustic boundary conditions and loads are applied:
A unit force is applied on the voice coil using surface effect element SURF154. A resulting load per unit area of 2425.21892 is applied on face 2. The value is constant with respect to frequency. Structural symmetry boundary conditions are applied to the x = 0 and z = 0 locations. The cabinet is assumed to be free to move and is unconstrained.
The outermost PML faces are constrained, with the pressure degree of freedom set to 0 to specify the truncated domain location. The naturally occurring boundary condition in acoustics is a symmetry boundary condition, so no specification on the acoustic elements is necessary to designate a symmetry plane.
In the following example input, an FSI flag is applied to predefined nodal component “FSI” to designate acoustic faces that have fluid-structure interaction calculations activated:
d,PML,pres,0 esel,s,ename,,220,221 sf,FSI,fsi allsel,all cmsel,all
The acoustic elements must be selected first, as the FSI flag is applied only to acoustic element faces, and not structural element faces that share the same nodes.