ANSYS, Inc. Release Notes
ANSYS, Inc. Release Notes
This release of the Meshing application contains many new features and enhancements, including completion of ANSYS CFX-Mesh user migration and evolutionary improvements to help GAMBIT, TGrid, and ANSYS ICEM CFD user migration. Areas where you will find changes and new capabilities include the following:
Note the following when resuming databases from previous releases:
ANSYS Workbench no longer supports the CFX-Mesh method. Upon import of a legacy model into release 13.0, any CFX-Mesh method controls will be made inoperable, and you must either delete the method manually or change it to a valid method type. If importing a *.cmdb file from Release 10.0 that contains CFX-Mesh data, you must first take the model into Release 11.0 and save it to convert it to a supported format for use in 13.0. In either case the geometry will be maintained, but the mesh method must be replaced.
The CutCell Cartesian mesh method has been added at release 13.0. CutCell meshing is a general purpose meshing method designed for ANSYS FLUENT. The CutCell meshing algorithm is suitable for a large range of applications, and due to the large fraction of hex cells in the mesh, often produces better results than tetrahedral methods. The CutCell method uses a patch independent volume meshing approach (surface mesh automatically created from boundary of volume mesh) without the need for manual geometry cleanup or decomposition, thereby reducing the turnaround time required for meshing.
The CutCell method is useful for meshing fluid bodies in single body parts and multibody parts; at release 13.0 it cannot be used to mesh assemblies of parts, nor a collection of loosely closed surface patches. CutCell is supported in the Meshing application only; it is not supported in the Mechanical application.
When Physics Preference is set to CFD and CutCell meshing is being used, a shape checking algorithm based on orthogonal quality is used. Orthogonal quality, which is new at release 13.0, is the recommended quality criterion for CFD simulations and can be used for all types of meshes including CutCell and polyhedral.
Process improvements such as direct meshing, mesh method interoperability, and improved failure handling have been made at release 13.0:
Using direct meshing, you can selectively pick bodies and mesh them incrementally, allowing you some control over meshing order. The Generate Mesh, Preview Surface Mesh, Preview Source and Target Mesh, and Preview Inflation ease of use features all support direct meshing. In the Tree Outline, the Meshed status icon will now appear for a meshed body within the Geometry folder, or for a multibody part whose child bodies are all meshed. If you make changes after meshing that invalidate the mesh for an individual body (such as adding sizing to the body), you will need to re-mesh that body only. This is in contrast to previous releases in which the entire part would need to be re-meshed. Direct meshing is supported for the following mesh methods: Patch Conforming Tetra, Patch Independent Tetra, MultiZone, Sweep, Hex Dominant, Quad Dominant, All Triangles, Uniform Quad/Tri, and Uniform Quad. Direct meshing is enabled by default, but you can use the Allow Direct Meshing option to disable it.
You can mix and match mesh methods on the individual bodies in a multibody part, and the bodies will be meshed with conformal mesh. Through this flexible approach, you can better realize the value of the various methods on the individual bodies. Refer to Conformal Meshing Between Parts for information about conformal meshing and mesh method interoperability. Also see Interactions Between Mesh Methods for information about how inflation is handled when more than one mesh method is being used.
When you mix mesh methods in multibody parts, the manner in which topology shared by multiple bodies is protected depends on whether adjacent bodies are being meshed with Patch Independent methods and/or Patch Conforming methods. Refer to Meshing by Algorithm and Direct Meshing for information about protected topology.
The new Verbose Messages from Meshing option controls the verbosity of messages returned to you. Depending on the setting, before meshing a message reports the subset of bodies that is going to be meshed and/or after meshing a message reports the subset of bodies that failed to mesh. In either case, you can right click on the message to view the bodies.
The new Extra Retries For Assembly option specifies whether the mesher should perform extra retries when meshing an assembly if meshing would otherwise fail due to poor mesh quality. These retries are in addition to the number specified by the Number of Retries option. Extra Retries For Assembly is available in the Advanced group under the Details view as well as in the Options dialog box.
For the Number of Retries option, there are new behaviors to be aware of, most of which are due to the introduction of direct meshing and mesh method interoperability:
Retries will not occur if you are using the Patch Independent Tetra or MultiZone mesh method in combination with any other solid mesh method to mesh bodies contained in the same part, or if you are using Uniform Quad/Tri or Uniform Quad in combination with any other surface mesh method to mesh bodies contained in the same part.
If Number of Retries is set to 0 and a single body in a multibody part fails during direct meshing, the mesher returns as much of the mesh as possible. Bodies with valid meshes will have a meshed state while bodies with invalid or partial meshes will have an unmeshed state. You can display and examine the partially meshed bodies and then apply more mesh controls to correct any problems you find. If Number of Retries is set to a value greater than 0 and any body fails to mesh, the mesher returns nothing for the given part. The return of a partial mesh is applicable to the Quad Dominant, All Triangles, Uniform Quad/Tri, Uniform Quad, Patch Independent Tetra, and MultiZone methods only. The Patch Conforming Tetra, Sweep (general or thin), and Hex Dominant methods cannot return partial meshes.
If you are performing direct meshing and at least one body of a particular part has been meshed successfully, no additional retries will occur if the mesh of a subsequent body within that same part fails.
For shell models, if the Advanced Size Function is on, the default values of Min Size, Max Face Size, and Defeaturing Tolerance are reduced automatically with each subsequent retry.
The following MultiZone mesh method enhancements have been made at release 13.0:
Source face automation has been improved.
Baffle meshing is supported by the MultiZone mesh method for free meshing. The body with a baffle must be meshed with a free mesh of tetrahedral elements. For this reason, you must set the Free Mesh Type to Tetra for bodies with baffles.
Program Controlled inflation is supported by the MultiZone mesh method.
The MultiZone mesh method now supports the Smooth Transition option for the Inflation Option control, along with the previously-supported Total Thickness and First Layer Thickness options. Smooth Transition is the default for MultiZone.
Improvements in imprinting include improved side face and body handling, as well as new support for models that contain multiple connected internal loops.
While mixing Sweep and MultiZone mesh methods, pre-meshed faces may be used in these ways:
Mapped faces can be supported as side faces when MultiZone or Sweep is used to mesh subsequent bodies. The pre-meshed faces may have been generated using either General Sweep or MultiZone. There are limitations on how the face is mapped. Simple mapped faces (that is, 4-sided) are supported; however, more complicated sub-mapped cases may cause problems.
Mapped faces can be supported as source faces.
Free faces (where mesh does not have a quad mapped pattern) can be supported as source faces only.
The following Patch Independent Tetra mesh method enhancements have been made at release 13.0:
Improvements have been made in quadratic memory handling.
The body sizing control is supported by the Patch Independent Tetra mesh method.
You can use the Smooth Transition and Growth Rate controls to further define the Patch Independent Tetra mesh method. The value of Smooth Transition determines whether the Octree volume mesh generated from the Patch Independent Tetra mesh method should be kept or whether it should be replaced with a Delaunay volume mesh starting from the Patch Independent surface mesh. When Smooth Transition is on, the volume mesh will be a Delaunay mesh. When Smooth Transition is off, the volume mesh will be an Octree mesh. The Growth Rate value represents the increase in element edge length with each succeeding layer of elements. Its Default value is affected by the settings of the Use Advanced Size Function and Smooth Transition controls.
The new Feature Angle control specifies the minimum angle at which geometry features will be captured when using the Patch Independent Tetra mesh method. If the angle between two faces is less than the specified Feature Angle, the edge between the faces will be ignored, and the nodes will be placed without respect to that edge. If the angle between two faces is greater than the Feature Angle, the edge should be retained and mesh aligned and associated with it (note the edge could be ignored due to defeaturing, etc.).
The following Uniform Quad/Tri and Uniform Quad mesh method enhancements have been made at release 13.0:
If you select the Uniform Quad/Tri or Uniform Quad mesh method to mesh a multibody part that contains a mix of line bodies and surface bodies, all surface bodies and all line bodies that share edges with surface bodies will be meshed with the selected method. Any remaining line bodies (where only vertices are shared with surface bodies) will be meshed with the Quad Dominant mesh method.
The Element Midside Nodes option is now supported for the Uniform Quad/Tri and Uniform Quad mesh methods, allowing you to choose between a quadratic or linear mesh.
The Uniform Quad/Tri and Uniform Quad mesh methods are available for 2D models.
The following enhancements to defeaturing have been made at release 13.0:
The Pinch group of global mesh controls has been replaced by the new Defeaturing group. The Pinch controls are now located under the Defeaturing group, along with the new global defeaturing tolerance controls and loop removal controls. Turning on the new Automatic Mesh Based Defeaturing option exposes the Defeaturing Tolerance option, where you can specify a global tolerance for defeaturing. Using the loop removal controls—which apply only to sheet models—you can instruct the Meshing application to remove loops automatically according to the criteria you specify. Prior to meshing, you can use the Show Removable Loops feature to preview the loops that will be removed according to the current settings. The user interface controls for defeaturing tolerance and loop removal (where applicable) are now consistent across the Patch Conforming Tetra, Patch Independent Tetra, MultiZone, Sweep, Hex Dominant, Quad Dominant, All Triangles, Uniform Quad/Tri, and Uniform Quad mesh methods.
The Pinch feature has been extended to include support for face-edge and face-vertex pinch controls. In addition, overall usability of the Pinch feature has been improved with the introduction of the Set As Pinch Master/Slave and Add To Pinch Master/Slave context menu options and the Snap to Boundary control.
The Pinch feature now supports the use of the same master in more than one manual pinch control. This is true for all types of manual pinch controls: edge-edge, edge-vertex, vertex-vertex, face-edge, and face-vertex. When multiple pinch controls use the same master, the aggregate of the pinch controls is used to determine the pinch.
The following enhancements to sheet model default handling have been made at release 13.0:
Better defaults for sheet models have been implemented. When Use Advanced Size Function is on, the default Defeaturing Tolerance for sheets is 75% of the value of Min Size. (For solids, it is 50% of the value of Min Size.)
When Physics Preference is set to Mechanical or Explicit, Use Advanced Size Function is set to On: Curvature for sheet models by default.
The Max Size option (which was known as the Max Tet Size option in previous releases) is hidden if no solids are present in a model.
At release 13.0, the Write ICEM CFD Files control has been moved from the Options dialog box (Tools> Options) to the Details view of the Uniform Quad, Uniform Quad/Tri, Patch Independent Tetra, and MultiZone mesh methods. The control has been extended to include options for running ANSYS ICEM CFD interactively or in batch mode from an ANSYS ICEM CFD Replay file.
The following enhancements related to large scale meshing have been made at release 13.0:
Speed improvements have been made across the board, but especially for surface and hex meshing.
Better memory management for Patch Conforming Tetra has been implemented.
The Number of CPUs option has been added to the Options dialog box in support of same machine parallel (SMP) meshing (for multiple cores; not supported for clusters). Using this option you can specify a number of processors from 0 to 256. Specifying multiple processors will enhance the performance of the Uniform Quad, Uniform Quad/Tri, Patch Independent Tetra, and MultiZone mesh methods. This option has no effect when other mesh methods are being used.
In release 13.0, you can parameterize global and local mesh controls for use in the ANSYS Workbench Parameter Workspace.
New at release 13.0, you can use the Virtual Split Edge feature to split one edge into two virtual edges. You can define the location of the split either by picking the location in the Geometry window or by specifying a numerical value in the Details View. Using the F4 key, you can interactively adjust previously defined virtual edge splits.
At release 13.0, mixed order meshing is now supported for the Patch Independent Tetra, MultiZone, Uniform Quad/Tri, and Uniform Quad mesh methods. To use mixed order meshing with these methods, all of the bodies in the part must be meshed with the same mesh method [that is, either all Patch Independent Tetra, all MultiZone, or all Uniform Quad(/Tri)].
The following inflation control enhancements have been made at release 13.0:
Improved pre-inflation smoothing has led to less stair stepping and better quality during layer compression.
For pre-inflation, new options are available for the Inflation Option control. The new options, called First Aspect Ratio and Last Aspect Ratio, allow you to control the heights of the inflation layers by defining the aspect ratio of the elements that are extruded from the inflation base.
To simplify inflation control specification, you can define inflation boundaries via Named Selections (one or more for the faces in 3D models, or one or more for the edges in 2D or Sweep models).
The following enhancements to ease of use features have been made at release 13.0:
In the area of ease of use features, Show and Preview RMB menu options have been reorganized under new Show and Preview flyout menus. In addition, a new Parts flyout menu has been created to organize the Generate Mesh, Preview Surface Mesh, and Clear Generated Data menu options when they are selected via RMB on the Geometry window.
A Graphics Options toolbar has been added to help diagnose potential problems with a geometry's topology and connectivity.
To assist you in mapped face meshing, you can use the new Show Mappable Faces feature to highlight mappable faces prior to defining mapped face meshing controls, which provide more guidance to the mesher.
You can use the new Show Missing Tessellations feature to highlight geometry with missing facets prior to generating the mesh. This feature is available only for the CutCell and Patch Independent Tetra mesh methods.
You can Clear Generated Data on a selected part or body.
The following improvements to size functions have been made at release 13.0:
Body of influence now behaves as a soft setting instead of a hard setting, making it more useful for external aerodynamics problems.
The proximity size function is not applied between faces that share an edge or between edges that share a vertex, reducing unnecessary refinement in Patch Conforming Tetra meshing.
Transitioning between swept and tetra meshes with inflation has been improved.
The following changes and behaviors are new at release 13.0:
The Max Tet Size option, which was available in previous releases, has been renamed the Max Size option.
You cannot apply a match control to topology on which a face-edge pinch, mesh connection, or symmetry control has been applied. In cases involving a match control and a pinch control, the match control will be suppressed and the reason (Overridden) will be reported in the Active read-only field in the Details view. In cases involving match with either mesh connection or symmetry, an error message will be issued.