In this blog post we will look at some important highlights of the new features for Simcenter STAR-CCM+ version 2021.3. This version of the software was released this week and contains several improvements worth highlighting. This post will focus on the features most relevant to a broad audience. Where we will focus on the topics of user experience, 3D-CAD, mesh pipeline, fluid flow and turbulence.
I will also take the opportunity to remind once again, that a full list of new features for the latest version can be found in the documentation. It is accessed with the installation of said software. Opening the latest version and selecting help or simply pressing F1 will take you to the correct location on your disk, using a html extension.
Service – Xcelerator share
Note that the feature presented here is NOT part of the standard licencing options for Simcenter STAR-CCM+. Contact your sales representative for more information.
As part of securing for the future, Siemens now provide a service called Xaas and a large part of that functionality includes what is presented as Xcelerator share. This is a cloud-based collaboration that allows for file sharing and accessing material directly form the GUI. Via a login you can simply access your files. It facilitates for close collaboration between groups in a project, and works does not replace Teamcenter, but rather complement it. See the example below to build an understanding of the possibilities.
3D-CAD – Support tessellation
Previously the commonly used surface mesh formats like STL, Jt Open and dbs, has been possible to import as parts into the Simcenter STAR-CCM+ tree structure. With this release you can import these formats into 3D-CAD. This facilitates for faster geometry organization. The video below shows the feature and that the search-function is still valid with these types of files.
Meshing – Advancing Layer Mesher (ALM)
The Advancing layer mesher is complement method to the prism layer mesher. In some instances where the prism layer mesher fails, the ALM can get you a desired result instead. The main difference in methodology between advancing layer mesher and the prism layer mesher is that the ALM perform the building of layers first, and then creates a bulk mesh. While the prism layer mesher uses the mesh of an already created bulk in creating the layers.
However, one large update for this method, is a speed up in the process, since now the core mesh when using ALM is done in parallel. The layers with ALM are still made in serial, so the relative speedup for meshing in a case with ALM is heavily dependant on the prism/core mesh ratio.
Another big update for the ALM is the fact that it is now possible to combine with Anisotropic meshing. This allows for efficient mesh distribution to capture high curvature geometry. Mainly the mesh generation becomes faster because the cell count is reduced. The picture below shows a comparison, and the agreement between isotropic and anisotropic mesh looking at longitudinal velocity. The test case is the DARPA SUBOFF public test case (Geometry can be found here DARPA Suboff | 3D CAD Model Library | GrabCAD). The cell saving of employing anisotropic ALM is 19%.
The below video show how to use it in your case. Note also, that there are some limitations. The ALM supports only tetrahedral and polyhedral meshes.
Heat Transfer – New external radiation workflow
There have been some changes to the workflow when simulating radiation, where improvements have been implemented. Mainly, the surface orientation option has been removed. Instead, you will now have the option of making a region radiate only internally, only externally or both. Also, the wall boundary condition of Environment has been merged into Convection. This change results in that the thermal resistance option is now activated by the convection option. Meaning that thermal radiation can be enforced in addition to other thermal boundary conditions.
In version 2021.3 there is also more helpful and meaningful post-processing when it comes to simulation radiation (S2S). Some new field functions allow for better visualisation of results. These new field functions significantly simplify the identification of radiating parts that are responsible for unwanted thermal hotspots.
Aeroacoustics – Lighthill Wave model
The Lighthill wave model is a new hybrid aeroacoustics modelling approach. Compared to the existing hybrid approach (the Acoustic Wave model), this new model has higher usability, reduced error, improved performance and accuracy. It is especially beneficial for HVAC simulations.
Using the old model approach, the Acoustic Wave model, the user has to set up noise source blending functions to exclude parts of the domain which generates spurious noise. The results are also very sensitive to noise source regions and to the numerics, while with the new model there is no spurious noise at mesh transition and no need for complex noise source regions. The picture below shows a comparison between the new and old method compared to experiments experiments.
The new methods also allow for a reduced turnaround time due to the possibility of using a coarser mesh and fewer inner iterations.
It is now possible to Export 3D-CAD models. This means that you can “export parametric CAD” to allow for simple transfer CAD between files. The suppress and rollback features in 3D-CAD are not exported.
Light weight display is a new option in which you can view your model with a lowered resolution, and lower level of detail, while a significant speed up is employed.
Part shells included in offset allows for creation of an offset surface around a shell part.
It is now possible to select or deselect Part surfaces in morph surface mesh operation. Where before you included a full part, you can now keep better control by including or excluding specific part surfaces.
There is now Expression input for under-relaxation factors (URF) and CFL Ramps. You can also use expressions for the turbulent viscosity solver. This improvement reduces the need for scripting and enables for easier use of Simulation operation with global parameters.
As usual we at Volupe hope that this has been useful for you and that it will help you with your simulations in Simcenter STAR-CCM+. Do not hesitate to reach out to firstname.lastname@example.org if you have any questions. Next week’s blog post will mainly focus on the news regarding multiphase simulations. One example of a new feature is meshless DEM.