External FEM Acoustics workflow creates external acoustic sound radiation domain to predict the propagation of radiated sound in the near field and far field due to vibration of the external surface of the structural assembly or flow source port of the fluid flow.
External FEM Acoustics workflow can create different domain shape as per your requirement. The available options are Convex Irregular Shape Enclosure (Irregular Body Fitted Convex), External Part Enclosure (custom domain shape through imported CAD file), Spherical Enclosure, Hemispherical Enclosure. All mesh domains have the option to create near field acoustic domain mesh which is enough for radiation or infinite element boundary condition. You also have the option to add Perfectly Matched Layers (PML/IPML) to define PML boundary condition.
When you select Mesh Workflows as External FEM Acoustics, Mesh Workflow loads a predefined template with Steps and Outcomes. Mesh Workflow performs the Steps through Controls and Outcomes to achieve the desired mesh for the External FEM Acoustics.
External FEM Acoustics workflow has the following steps:
Fill Holes: Fill the holes defined in the Hole Filling step. The operation type available for Fill Holes is Fill Holes.
Wrap Parts: Wraps the selected parts. The operation type available for Wrap Parts is Wrap.
Improve Wrap Mesh: Improves the surface mesh. The operation type available for Improve Wrap Mesh is Mesh Surface.
Create Enclosure: Creates the enclosure around the specified scope. The operation type available for Create Enclosure is Create Enclosure.
Mesh Volume: Creates the volumetric mesh. The operation type available for Mesh Volume is Mesh Volume.
Improve Volume Mesh:Improves the volumetric mesh generated in the Mesh Volume step. The operation type available for Improve Volume Mesh is Improve Volume Mesh.
Extrude Acoustic Region : Generates layers of prismatic elements from the input surface to a specified height. The generated volume may have layers of constant size hexahedral or triangular prism elements depending on the input surface. The operation type available for Extrude Acoustic Region is Extrude.
Extrude PML/IPML Region: Generates layers of prismatic elements from the acoustic region to a specified height. The generated volume may have layers of constant size hexahedral or triangular prism elements depending on the input surface. The operation type available for Extrude PML/IPML Region is Extrude.
Note: You can add or delete Extrude PML/IPML Region as per your requirement. You can create PML/IPML layers extruding the external surface layer based on the Number of Layers and Per Layer Height you specify.
Create Acoustic Regions: Creates the topology from the mesh only model. The operation type available for Create Acoustic Regions is Create Topology.
Merge Acoustic Regions: Merges the volume. The operation type available for Merge Acoustic Regions is Merge Volumes.
Assign Physics Properties: Defines material properties and thickness on the scoped parts or zones. The operation type available for Assign Physics Properties is Manage Zone Properties.