![\"\"](\"https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/6\/2020\/04\/Corvette_Template5_23@done_BlogAR5-1-1024x717.png\")
<\/figure>\n\n\n\nIn CFD modeling, there are three key ways in which Simcenter STAR-CCM+ can help you handle complex geometries in your simulation. Let us look at one of the most complex systems and CFD simulations in the world \u2013 Vehicle Thermal Management (VTM) for a full passenger car, in this case the formidable Corvette. <\/p>\n\n\n\n
Easily Organize Complex Models for Simulation<\/strong> <\/h2>\n\n\n\nThe Corvette model shown below has more than 15,000 parts, not all of which are needed for the simulation. Manually searching for and organizing the parts can involve thousands of clicks, miles of mouse travel, and several units of your favorite caffeinated beverage to get the job done. <\/p>\n\n\n\n
Fortunately, several capabilities\u202fexist to simplify the job, including tags<\/a>, filters<\/a>, and query-based selection<\/a>s in Simcenter STAR-CCM+. These allow you to more efficiently organize large complex assemblies and ultimately automate the mesh pipeline. <\/p>\n\n\n\nTo organize the Corvette model, you can: <\/p>\n\n\n\n
\n- Tag the parts to create a new grouping without altering\u00a0the original\u00a0imported\u00a0hierarchy\u00a0(so don\u2019t be afraid to try it out).\u00a0Groupings\u00a0can be\u00a0made\u00a0based on\u00a0qualities like \u2018material\u2019\u00a0or solid part or exterior parts of the\u00a0car:\u00a0for example,\u00a0all\u00a0the plastic parts in\u00a0the\u00a0powertrain can be\u00a0grouped and combined\u00a0as\u00a0a single part.\u00a0This allows\u00a0you\u00a0to organize and reduce the number of parts used as input to fluid regions.\u00a0<\/li>\n<\/ul>\n\n\n\n
\n- Use the\u00a0tags as an input\u00a0in\u00a0filters or the query-based selection in the mesh operation pipeline.\u00a0Using the filter to create a query-based selection makes it possible to find and select objects in the simulation tree without having to do it manually, producing more accurate results in a fraction of the time.\u00a0\u00a0<\/li>\n<\/ul>\n\n\n\n
![\"\"](\"https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/6\/2020\/04\/Organizse_File1-1024x668.png\")
Before and after organizing complex models for CFD simulation<\/em> <\/figcaption><\/figure><\/div>\n\n\nAfter organizing the model using tags and groups, the model\u2019s original count of 15,000 parts has been reduced to around 8,000 for the VTM simulation. The image below shows the re-organized hierarchy tree for parts. <\/p>\n\n\n\n
Reduce Turnaround Time from Weeks to Hours<\/strong> <\/h2>\n\n\n\nLast year during a Simcenter Conference training session called \u201cMeshing made Easy,\u201d attended by simulation engineers from around the world, the trainer asked the question, \u201cHave you ever seen perfect geometry?\u201d Not a single attendant raised their hand \u2013 no one in the room was confident enough to say that they had ever gotten perfect geometry that was simulation-ready. Seeing perfect geometry is equivalent to seeing a flying unicorn! <\/p>\n\n\n\n
In a model with a few parts, CAD preparation involves cleaning up the dirty geometry, unite the parts, and extract the fluid volume manually without any problem. The same workflow, however, cannot be used to handle a full vehicle or a ship model; a manual geometry preparation of model with thousands of parts equates to weeks or months of tedious work, putting serious speed limits on product development. You need to go from CAD-to-Solution rapidly in order to study and produce the best designs. <\/p>\n\n\n\n
One way to achieve this is with the Simcenter STAR-CCM+ Surface Wrapper tool, which creates a geometric representation of the model by \u201cshrink-wrapping\u201d a high-resolution triangulated surface on the complex aspects of the geometry. If doing a VTM analysis on our Corvette model, the entire car along with the ambient air surrounding the car can be easily generated with our surface wrapper technology in just a few clicks. The goal of using the surface wrapper is to prevent leakage into the main cabin, avoid geometry issues (missing faces, gaps, intersecting parts), capture the original geometry features, and make sure there is no artificial intersection between parts. Contact prevention, Gap closure, and Surface Wrapper Defeature options provide more controls to capture enough data from geometry. <\/p>\n\n\n\n![\"\"](\"https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/6\/2020\/04\/Corvette_Template5_23@done_CopyMesh_Copy-of-Blog-1024x569.png\")
Surface mesh-generated for underhood parts of a Corvette model<\/em> <\/figcaption><\/figure>\n\n\n\nFast, Robust, Pipelined Mesh Operations<\/strong> <\/h2>\n\n\n\n Next, you need to create a volume mesh for simulation. The mesh operation pipeline allows you to create a custom workflow that suits the needs of an application. With pipelined operations, the user can automate the execution, keep track of the operation sequence, and revert them in a fully reversible approach. After surface wrapping the Corvette model, you can add the automated mesh and weak contact creator in the mesh pipeline to create the final volume meshing for the VTM simulation (see image below). <\/p>\n\n\n\n![\"\"](\"https:\/\/blogs.sw.siemens.com\/wp-content\/uploads\/sites\/6\/2020\/04\/2020-01_Corvette_steady_noMesh_Mesh_Done_Cell-volume-2_2-1024x542.png\")
The final volume mesh for the VTM simulation generated by the mesh pipeline.<\/em> <\/figcaption><\/figure>\n\n\n\nIntegrated CAD Environment <\/strong> <\/h2>\n\n\n\nNext, changes to the design often need to be made. In our example, if the Corvette model needs to be investigated for the overall aerodynamic drag reduction impact on front end cooling then the grill, bumper vents, and radiator fan parts need to be parameterized. This can be easily done through our very own built-in 3D-CAD platform which allows you to create and parameterize CAD models without having to use external tools or depend on a design engineer to parameterize parts of a design study.\u202f <\/p>\n\n\n\n
To organize the Corvette model, you can: <\/p>\n\n\n\n
- \n
- Tag the parts to create a new grouping without altering\u00a0the original\u00a0imported\u00a0hierarchy\u00a0(so don\u2019t be afraid to try it out).\u00a0Groupings\u00a0can be\u00a0made\u00a0based on\u00a0qualities like \u2018material\u2019\u00a0or solid part or exterior parts of the\u00a0car:\u00a0for example,\u00a0all\u00a0the plastic parts in\u00a0the\u00a0powertrain can be\u00a0grouped and combined\u00a0as\u00a0a single part.\u00a0This allows\u00a0you\u00a0to organize and reduce the number of parts used as input to fluid regions.\u00a0<\/li>\n<\/ul>\n\n\n\n
- \n
- Use the\u00a0tags as an input\u00a0in\u00a0filters or the query-based selection in the mesh operation pipeline.\u00a0Using the filter to create a query-based selection makes it possible to find and select objects in the simulation tree without having to do it manually, producing more accurate results in a fraction of the time.\u00a0\u00a0<\/li>\n<\/ul>\n\n\n\n
Before and after organizing complex models for CFD simulation<\/em> <\/figcaption><\/figure><\/div>\n\n\n After organizing the model using tags and groups, the model\u2019s original count of 15,000 parts has been reduced to around 8,000 for the VTM simulation. The image below shows the re-organized hierarchy tree for parts. <\/p>\n\n\n\n
Reduce Turnaround Time from Weeks to Hours<\/strong> <\/h2>\n\n\n\n
Last year during a Simcenter Conference training session called \u201cMeshing made Easy,\u201d attended by simulation engineers from around the world, the trainer asked the question, \u201cHave you ever seen perfect geometry?\u201d Not a single attendant raised their hand \u2013 no one in the room was confident enough to say that they had ever gotten perfect geometry that was simulation-ready. Seeing perfect geometry is equivalent to seeing a flying unicorn! <\/p>\n\n\n\n
In a model with a few parts, CAD preparation involves cleaning up the dirty geometry, unite the parts, and extract the fluid volume manually without any problem. The same workflow, however, cannot be used to handle a full vehicle or a ship model; a manual geometry preparation of model with thousands of parts equates to weeks or months of tedious work, putting serious speed limits on product development. You need to go from CAD-to-Solution rapidly in order to study and produce the best designs. <\/p>\n\n\n\n
One way to achieve this is with the Simcenter STAR-CCM+ Surface Wrapper tool, which creates a geometric representation of the model by \u201cshrink-wrapping\u201d a high-resolution triangulated surface on the complex aspects of the geometry. If doing a VTM analysis on our Corvette model, the entire car along with the ambient air surrounding the car can be easily generated with our surface wrapper technology in just a few clicks. The goal of using the surface wrapper is to prevent leakage into the main cabin, avoid geometry issues (missing faces, gaps, intersecting parts), capture the original geometry features, and make sure there is no artificial intersection between parts. Contact prevention, Gap closure, and Surface Wrapper Defeature options provide more controls to capture enough data from geometry. <\/p>\n\n\n\n
Surface mesh-generated for underhood parts of a Corvette model<\/em> <\/figcaption><\/figure>\n\n\n\n Fast, Robust, Pipelined Mesh Operations<\/strong> <\/h2>\n\n\n\n
Next, you need to create a volume mesh for simulation. The mesh operation pipeline allows you to create a custom workflow that suits the needs of an application. With pipelined operations, the user can automate the execution, keep track of the operation sequence, and revert them in a fully reversible approach. After surface wrapping the Corvette model, you can add the automated mesh and weak contact creator in the mesh pipeline to create the final volume meshing for the VTM simulation (see image below). <\/p>\n\n\n\n
The final volume mesh for the VTM simulation generated by the mesh pipeline.<\/em> <\/figcaption><\/figure>\n\n\n\n Integrated CAD Environment <\/strong> <\/h2>\n\n\n\n
Next, changes to the design often need to be made. In our example, if the Corvette model needs to be investigated for the overall aerodynamic drag reduction impact on front end cooling then the grill, bumper vents, and radiator fan parts need to be parameterized. This can be easily done through our very own built-in 3D-CAD platform which allows you to create and parameterize CAD models without having to use external tools or depend on a design engineer to parameterize parts of a design study.\u202f <\/p>\n\n\n\n
- Use the\u00a0tags as an input\u00a0in\u00a0filters or the query-based selection in the mesh operation pipeline.\u00a0Using the filter to create a query-based selection makes it possible to find and select objects in the simulation tree without having to do it manually, producing more accurate results in a fraction of the time.\u00a0\u00a0<\/li>\n<\/ul>\n\n\n