10.4.8. ATM3D

ATM3D is an alternative meshing approach to ATM. Whereas the original ATM meshing process uses a quasi-3D mesh smoothing process, ATM3D uses a full 3D mesh smoothing process. The goal of ATM3D is to ultimately produce a higher quality mesh, particularly for cases that are challenging for ATM.

Initially, ATM3D is not active by default. To use it by default, select Edit > Options, then, in the Options dialog box, with TurboGrid selected in the tree, select Use ATM3D Meshing By Default and click OK. This preference takes effect the next time you start TurboGrid.

For a given case, you can activate ATM3D by opening Topology Set and setting Mesh Generation Mode to ATM3D.

Limitations of ATM3D

  • Geometry: Cut-off blade geometry is not supported: If the geometry has a cut-off blade, ATM3D is turned off regardless of the Use ATM3D Meshing By Default preference setting. For details, see Cut-off or square.

  • Layers: Compared to ATM, ATM3D has less need to adjust the number of layers. When using ATM3D, the Layers object's Layers tab > Intermediate Layers > Insertion Mode setting can only be set to Manual - Uniform. You can only change the number of intermediate layers via the Count setting. For details, see Defining Intermediate Layers.

  • Layers: Unlike the ATM approach, ATM3D does not have a setting to change the type of the spanwise mesh interpolation guide curves that connect the layers. For details, see Spanwise Mesh Interpolation Guide Curves.

  • Mesh Data: Inserting/editing edge splits is not supported. For details, see Changing the Number of Elements on a Selected Master Topology Edge.

Also see Table 10.2: Mesh Generation Mode Comparison.

Note:

  • If you encounter high aspect ratio elements along the leading/trailing edge, or elements with poor angles:

    • Try adjusting the number of layers.

    • Try increasing the value of parameter Domain Meshing Smoothing Iterations After Remesh. This parameter is accessed by right-clicking the 3D Mesh object and selecting Edit in Command Editor.

  • With ATM3D, layers show neither the refined boundary layer mesh around the blade nor the blade tip mesh. You can, as usual, inspect the mesh using the 3D Mesh > Show Mesh object.