Exporting Data to wave6

Export of Surface Geometries

Exporting surface geometry data enables you to benefit from the surface handling capabilities of Simcenter STAR-CCM+, such as CAD import or surface preparation, before you create a vibro-acoustics model in wave6.

To transfer surface geometry data from Simcenter STAR-CCM+ to wave6 use one of the following file formats:

• Nastran Shells (*.nas)
• Stereolithography File (*.stl)

The .nas file format is useful for exporting geometries in which the surfaces are defined as separate groups. Be aware that .nas is an ASCII file format and thus file size can be large for large models. The .stl file format is a binary format and therefore more compact. The .stl format is the recommended format for exporting surfaces when you do not require grouping of individual surfaces.

To export from Simcenter STAR-CCM+, follow the instructions for Exporting a Part.

Export of Volume Meshes

Exporting volume meshes enables you to benefit from the volume meshing capabilities of Simcenter STAR-CCM+ before you define finite element solids and cavities in wave6.

wave6 supports arbitrary linear and quadratic finite elements. In Simcenter STAR-CCM+ you can generate appropriate element topologies by using the following mesh operations:

• Directed Mesh
• Automated Mesh that uses the Tetrahedral Mesher and, optionally, the Thin Mesher.

The Directed Mesh operation generates linear hexahedral elements (Hex8) and the Tetrahedral Mesher generates linear tetrahedral elements (Tet4). An Automated Mesh Operation that combines the Tetrahedral Mesher and the Thin Mesher generates linear wedge elements (wedge6) in thin geometry parts, but can also create linear hexahedral (Hex8) or linear pyramids (Pyramid5) as transition elements.

To transfer volume meshes from Simcenter STAR-CCM+ to wave6 use the following file format:

• CCM files (*.ccm)

To export from Simcenter STAR-CCM+, follow the instructions for Exporting Mesh Data.

To import into wave6:

1. Create a new Fe Model Importer.
2. Select the New Fe importer node and set the following properties:

   Property		Setting
   File name		Click on the folder icon to browse to the .ccm input file.
   File format		.ccm (StarCCM+)
   Import mesh as		FE model

3. Right-click the New Fe importer node and select Import.

Export of Fluctuating Surface Pressures

Exporting fluctuating surface pressures enables you to take time domain surface pressures from an unsteady Simcenter STAR-CCM+ simulation and use them to define surface loads on structures in a wave6 model. This approach is particularly useful to model wind noise effects, such as side mirrors generate in the automotive industry.

To export from Simcenter STAR-CCM+:

1. Before running the simulation, set up an Auto Export following the instructions for Automatically Exporting Mesh and Solution Data at Regular Intervals
2. In the Auto Export dialog set the following nodes specifically for surface pressure export:

   Node		Value
   File Format		Surface fft files (*.trn)
   Scalar Functions		Select the relevant pressure fields. For example: for side mirror wind noise problems, export Pressure and Acoustic Pressure (available through the Acoustic Wave Model).
   Boundaries		Select the boundaries of interest.

3. Run the simulation.

To import into wave6, do the following for each field function:

1. In the object tree, right-click the Operations > Import > CFD importers node and select Create Fluctuating Surface Pressure Importer.
2. Select the New fluctuating surface pressure importer node:
   1. Set the following General properties:

      Property		Setting
      File name		Click on the folder icon to browse to the .trn input file.
      File format		.trn (STAR-CCM+ 3D)
      Field name		Enter the name of the field function exported from Simcenter STAR-CCM+.
      Boundary name(s)		Optionally, enter the names of specific Simcenter STAR-CCM+ boundaries.
      Fluctuating surface pressure load		Select the relevant Fluctuating Surface Pressure object defined within your wave6 model (located under Loads > Surface Load > Fluctuating Surface Pressure).

   2. Set the Mapping Options and Signal Processing Options properties as required.
3. Right-click the New fluctuating surface pressure importer node and select Import.

Export of Fluctuating Fan Sources

Exporting fluctuating fan sources enables you to take time domain surface pressures from an unsteady Simcenter STAR-CCM+ simulation and use them to define noise sources in an acoustic fluid in a wave6 model. This approach is particularly useful to model sound radiation, propagation, and scattering of rotating fans and propellers to account for installation effects.

To transfer fluctuating fan sources from Simcenter STAR-CCM+ to wave6 use the following file format:

• Surface fft files (*.trn)

To export from Simcenter STAR-CCM+:

1. Before running the simulation, set up an Auto Export following the instructions for Automatically Exporting Mesh and Solution Data at Regular Intervals.
2. In the Auto Export dialog set the following nodes specifically for fan source export:

   Node		Value
   File Format		Surface fft files (*.trn)
   Scalar Functions		Pressure
   Boundaries		Select the boundaries of interest.

3. Run the simulation.

To import into wave6:

1. In the object tree, right-click the Operations > Import > CFD importers node and select Create Fluctuating Fan Source Importer.
2. Select the New fluctuating fan source importer:
   1. Set the following General properties:

      Property		Setting
      File name		Click on the folder icon to browse to the .trn input file.
      File format		.trn (STAR-CCM+ 3D)
      Field name		Pressure
      Boundary name(s)		Optionally, enter the names of specific Simcenter STAR-CCM+ boundaries.
      Fluctuating surface pressure load		Select the relevant Fluctuating Fan Source object defined within your wave6 model (located under Loads > Volume Load > Fluctuating Fan Source).

   2. Set the Mapping Options and Signal Processing Options properties as required.
3. Right-click the New fluctuating fan source importer node and select Import.

Export of Fluctuating Surface Pressure Gradients

Exporting fluctuating surface pressure gradients enables you to take time domain surface pressure gradients on rigid surfaces in an unsteady Simcenter STAR-CCM+ model and use them to define aero-acoustic loads on the boundaries of acoustic spaces in a wave6 model. An example application is modeling aero-acoustic rush noise in a muffler at higher frequencies.

To transfer fluctuating surface pressure gradients from Simcenter STAR-CCM+ to wave6 use the following file format:

• Surface fft files (*.trn)

To export from Simcenter STAR-CCM+:

1. Before running the simulation, select the Solvers > Segregated Flow node and activate Temporary Storage Retained to provide the field function Apparent Pressure Gradient.
2. Create the following field function to calculate the surface normal pressure gradient:

   dot($$ApparentPressureGradient,$$Area.unit())

3. Set up an Auto Export following the instructions for Automatically Exporting Mesh and Solution Data at Regular Intervals
4. In the Auto Export dialog set the following nodes specifically for the export of surface pressure gradients:

   Node		Value
   File Format		Surface fft files (*.trn)
   Scalar Functions		Select the field function created in step 2.
   Boundaries		Select the boundaries of interest.

5. Run the simulation.

Export of Fluctuating Surface Stresses

Exporting fluctuating surface stresses enables you to predict a time domain 2D Maxwell surface stress along a curve in Simcenter SPEED/Simcenter STAR-CCM+ and then bring it into wave6 to describe a frequency domain surface load in a 3D VA model. This approach is particularly useful for modeling noise and vibration from electric machines when you have excitation from rotating magnetic fields.

To transfer fluctuating surface stresses from Simcenter STAR-CCM+ to wave6 use the following file format:

• Surface fft files (*.trn)

To export from Simcenter STAR-CCM+:

1. Before running the simulation, set up an Auto Export following the instructions for Automatically Exporting Mesh and Solution Data at Regular Intervals
2. In the Auto Export dialog set the following nodes specifically for the export of surface stresses:

   Node		Value
   File Format		Surface fft files (*.trn)
   Scalar Functions		Electromagnetic Force Density
   Boundaries		Select the boundaries of interest.

3. Run the simulation.

Export of Time-Averaged Volumetric Data

Exporting time-averaged volumetric data enables you to take pressure and temperature data from a thermal analysis in Simcenter STAR-CCM+ and use them to calculate the acoustic properties in a wave6 finite element acoustic model. This approach is particularly useful for applications that involve hot gases, where a non-uniform thermal/pressure distribution affects the acoustic wave propagation, such as in mufflers or combustion chambers.

To transfer time-averaged volumetric data from Simcenter STAR-CCM+ to wave6 use the following file format:

• CCM file (*.ccm)

To export from Simcenter STAR-CCM+:

1. Before running the simulation, create a Field Mean Monitor for each of the Pressure (absolute or relative) and Temperature field functions, see Sampling Data Values During and After the Solution.
2. Set the Field Mean Monitor properties accordingly to average the fields for the relevant regions over time, see Field Function Monitor Properties.

   Field functions related to the Field Mean Monitors are created automatically. Check the Title property of the monitors for the names of the field functions.

3. Run the simulation.
4. Export the field functions related to the Field Mean Monitors to a CCM file (*.ccm) following the instructions for Exporting Mesh and Solution Data.

To import into wave6:

1. In the object tree, right-click the Operations > Import > CFD importers node and select Create Acoustic Property Map Importer.
2. Select the New acoustic property map importer node and set the following properties:

   Property		Setting
   File name		Click the folder icon to browse to the .ccm input file.
   File format		.ccm (StarCCM+)
   Temperature field name		Enter the name of the field function that is related to the temperature averaging Field Mean Monitor.
   Pressure field name		Enter the name of the field function that is related to the pressure averaging Field Mean Monitor.
   Pressure option		Absolute or Relative, depending on the exported pressure data.

3. Right-click the New acoustic property map importer node and select Import.

   wave6 calculates the relevant acoustic properties, such as effective speed of sound or density, based on the imported data.