Before generating a mesh, review our meshing and CAD model best practices to ensure optimum results. You can generate multiple meshes within a project and swap between them. To view and select meshes, click on Mesh and select Swap Mesh.
After uploading a CAD model, click on the Mesh section within the control panel.
In the properties panel, click New Manual Mesh.
Adjust the meshing parameters in the properties panel. We'll walk through these options in the sections below.
Click on Mesh in the control panel. Scroll to the bottom of the properties panel and click Generate Mesh.
You will see a progress bar in the top left of the 3D Viewer that shows an estimate of your mesh size. You can cancel mesh generation at any time by clicking Cancel.
Note: We currently have limits of 200 million cells and two hours for the mesh to generate. If the mesh generation process exceeds either of these, it will be canceled automatically.
Sizing Strategy
Start by choosing a sizing strategy for your mesh:
Max Count | Generate a mesh based on the max cell count you specify. The default value is 200 million CVs.
If the mesh cell count exceeds the limit you provide, the mesh will be scaled back to the limit while maintaining the requested boundary layer profile. |
Target Count | Generate a mesh based on the target number of cells you specify. The default value is 200 million CVs.
The meshing parameters will be used to set the relative cell size, which will be scaled to meet the target cell count. As with the Max Count, the requested boundary layer profile will be maintained. |
Minimal Count | Generate a mesh to confirm your problem setup while keeping your time and credit spend low. This option will generate a coarse mesh without any other inputs. |
Mesh Size
Click Edit in the properties panel (or select Mesh Size from the control panel) to adjust the following parameters:
Min Size | Set the minimum size allowed for generated cells. |
Max Size | Set the maximum size allowed for generated cells. |
Applies to | Choose which volumes you'd like to apply the min and max values to.
If you want to set a different min and max for certain volumes, click + Custom Mesh Size and apply to the desired volumes. |
The default sizes for Min and Max are based on analysis of the smallest features of your model and overall size of the flow domain. While a mesh can be generated from these defaults, they are only a guide, and you will likely want to adjust both values to produce a better mesh.
Model
Click Edit in the properties panel (or select Model from the control panel) to adjust the following parameters:
Curvature | Set the sensitivity to curvature along the surfaces that you specify. A smaller angle means a larger sensitivity. |
Max Size | Set the maximum size along the surfaces that you specify. |
Applies to | Select the surfaces that make up the model.
If you want to set a different curvature and max size for certain surfaces, click + Custom Model and apply to the desired surfaces. |
Boundary Layer
Click Edit in the properties panel (or select Boundary Layer from the control panel) to adjust the following parameters:
Number of Layers | Set the number of boundary layers. The default value is 40. |
Initial Size | Set the height of the first cell above the surface. |
Growth Rate | Set the growth rate of cell heights away from the surface. |
Applies to | Select the surfaces to apply these options to.
If you want to set different boundary layer properties for certain surfaces, click + Custom Boundary Layer and apply to the desired surfaces. |
Refinement Regions
Sometimes specific areas of a mesh need additional resolution. Use refinement regions to set different sizing limits in specific areas of your mesh. Multiple refinement regions can be defined for a single mesh.
In the control panel, click the + icon next to Refinement Regions and choose from the following shapes. You will see the shape you’ve chosen over your model in the 3D Viewer.
Box |
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Cylinder |
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Sphere |
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💡Tip: Turn on the axes grid by clicking the grid icon at the top left of the toolbar to help you size and orient the shapes accurately.
Note: In a mesh with overlapping refinement regions, the smaller limit will be applied. This is also true if you are using the optional Auto Refinement Regions feature in addition to refinement regions. If the regions you have defined overlap the automatic refinement regions, the smaller limit will be applied.
Optional Properties
Click on the Mesh section in the control panel and scroll down to the bottom of the properties panel. There are two options:
Auto Refinement Regions | Check this box to enable automatic refinement of the mesh. This may be useful for complex external flow cases where you need to better capture flow features. It uses the definitions of which surfaces are part of the model that you set in the Model section and the Body Frame to determine the area around the model and the flow direction, and adds overlapping refinement areas in this zone. The sizes of the refined control volumes is proportional to the Max Size set for surfaces.
Note that this will create a larger total number of control volumes, which may result in slower simulations. For more precise refinement, use Refinement Regions. |
Proximity | Check this box to improve the quality of surface and volume meshes in areas with very small gaps between surfaces or around sharp edges of surfaces with boundary layers. |