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15.4.1 Boundary Layer Improvements in Trelis 16.0
15.4.2 New Features in Trelis
15.4.3 New Features in Trelis 16.3
15.4.4 New Features in 16.4
15.4.5 New Features in 16.5
2022.4+26187-e1209cf7 Apr 14, 2022

15.4 New In 16

15.4.1 Boundary Layer Improvements in Trelis 16.0

Trelis CFD 16.0 and Trelis Pro 16.0 support boundary layer meshing. Based on feedback from our CFD users Trelis 16.0 includes several enhancements to boundary layer processing. Below is a summary of the enhancements and improvements. Improved Quality

Overall element quality has been improved. In the example below the poorest element quality was 0.158 Scaled Jacobian before the improvements. The same model now contains no elements with quality lower than 0.463 Scaled Jacobian. Boundary Layers on Merged Surfaces

In some circumstances boundary layers on merged surfaces produced inverted pyramid elements, as seen in the left-hand image. This problem has been fixed as shown in the right-hand image. Boundary Layers Projected into Volume

In some circumstances, a boundary layer would not project correctly from a vertex into a volume. The problem is shown in the left-hand image. This problem has been fixed as shown in the right-hand image. Limited Support for Incrementally Adding Boundary Layers

Trelis CFD 16.0 and Trelis Pro 16.0 includes limited support for adding boundary layers, incrementally, while meshing. It should be noted this feature is new and may not work in all situations. Below are images showing two cylinders. The green and yellow cylinders share a common surface. The green cylinder contains a boundary layer and that cylinder is meshed. A boundary layer is added to the yellow cylinder and that cylinder is meshed. The existing boundary layer and mesh on the green cylinder is respected and preserved. The green cylinder includes a boundary layer. The green cylinder is meshed. A boundary layer is added to the yellow cylinder and it is meshed. The existing mesh on the green cylinder is respected.

15.4.2 New Features in Trelis

In addition to bug fixes and other improvements outlines in the Release Notes, Trelis includes many new features and enhancements.

Enhanced License Management

In previous versions of Trelis, in order to move a node-locked license from one computer to another, users were required to call technical support for assistance. For complete details about managing Trelis licenses, please see http://www.coreform.com/activate.

The Trelis Activation dialog for node-locked licenses now includes a "Deactivate" button. Users simply deactivate the license on computer A and then activate it on computer B. Trelis also includes a new dialog to see the status of all existing licenses. If a licensing error occurs, this dialog will show the problem, making it easier to diagnose and repair.

Updated to MeshGems 2.4-1

Measure Angle added to GUI Context Menu

MeshGems, from http://www.distene.com, includes bug fixes and enhancements. New functionality includes the integration of the "boundary recovery" algorithms when generating tet meshes, enhancing the success rate of very complex geometries.

When two curves or surfaces are selected, the user can select "Measure Angle" from the context menu. The computed angle between the two entities will be shown in the command output window.

Direction, Location, Plane, Axis Dialogs Improved

Added Wedges, Pyramids, Tet15 to Block Command Panel

These popup dialogs have been improved to include additional options, making them consistent with their associated commands.

Wedges, pyramids, and tet15 elements were added to the list of possible types when creating blocks.

New Warning for Block Operations

Added GUI to Modify Group Colors

Some users would assign geometry entities to a block, then perform additional destructive operations on those entities, such as webcuts or boolean operations. A warning has been added to inform the user to complete geometry operations on the geometry before assigning it to a block.

A command panel to modify the color of selected groups was added to Geometry/Group/Preferences.

Abaqus Exporter - Writing Additional File Types

Toggle Boundary Layer Visibility

The Abaqus exporter supports writing node files, element files, partial files, and flat files.

A new command, boundary_layer visibility on|off was added. A new tool button was added to support this new command.

Bug Fixes

  • Selecting 3D elements had an intermittent problem when selecting tet elements. This was fixed.

  • The Mesh Scaling GUI showed errors when using the "Maintain Mesh Features" option. This was fixed.

  • Boundary layers were duplicated during save/restore. This was fixed.

  • The Save As file type, when changing between .cub and .Trelis files would sometimes save the wrong type. This was fixed.

  • The Model Tree was not updating properly when importing some models that included multi-volume bodies. This was fixed.

  • A model may lose transparency when rotating. This was fixed. 

New Features in Trelis 16.1

In addition to bug fixes and other improvements outlines in the Release Notes, Trelis 16.1 includes the following new features and enhancements:

Smart Meshing Tool

Note: This new tool was introduced in Trelis 16.1. As of version 16.4 it has been removed from Trelis and moved into Bolt 2.0.

Coreform is continually looking for opportunities to make the power of Trelis more accessible and obvious. With Trelis 16.1 we have released the new Smart Meshing Tool. ITEM was designed to guide users through the complexities of hex meshing. The Smart Meshing Tool is a first step towards more automatic hex, tet, or mixed meshing. Simply tell the Smart Meshing Tool what bodies to mesh, set up the mesh scheme priority desired, indicate whether smoothing is desired, and hit "Run". The tool will use the power of Trelis’ automatic tools to produce a high-quality mesh if at all possible. See the documentation for more details.

New Model Tree

Rubber-band Selection using a Sphere

The Model Tree has been redesigned and rewritten. As a result, the tree is more efficient and much easier to replicate for 3rd-party developers who want to extend the graphical user interface for their customers’ needs. The underlying context-menu system was also redesigned making the user experience more consistent.

A new Sphere selection mode has been added to the rubber-band selection menu.

Copy Mesh Functionality Improvements

Mesh Scaling Improvements

The mesh copy surface command and command panel have been redesigned to be more robust and more precise and flexible. It is now possible to indicate specific vertices interior to the source and target surfaces which are to be matched during the copy. Any number of vertex pairs and vertex loops may be specified. This new functionality is documented here.

Mesh Scaling is an on-going area of research and development at Sandia National Labs, the creators of Cubit. Since Trelis is built on top of Cubit, Trelis users enjoy the benefits of Sandia’s excellent research. Mesh Scaling continues to improve in terms of functionality and robustness. Trelis 16.1 includes the latest version of Mesh Scaling.

Updated to MeshGems 2.3-4

Added volume (volume of a volume) to Extended Parsing

Trelis partners with the http://www.distene.com company and licenses their MeshGems tool suite for triangle and tetrahedral meshing as well as general surface cleanup for triangle meshing. Trelis 16.1 includes MeshGems version 2.3-4, the latest release from Distene.

The "volume" keyword was added to extended parsing. "Volume" refers to the volume of a 3-dimentional object such as a volume or body.

trelis> list volume with volume < 2.5

Parameterized Extended Selection Dialog

Trelis 16.0 introduced the Extended Selection Dialog. Selection filters, written in Python, did not accept input from users at runtime. With Trelis 16.1 users may interact with selection filters. The example shown below allows a user to input a selection radius and a selection type for target entities. 
New Features in Trelis 16.0

In addition to bug fixes and other improvements outlined in the Release Notes, Trelis 16.0 includes a handful of new features.

Improved Tri and Tet Meshing

Extended Selection Dialog

More http://www.distene.com™ Tri and Tet meshing controls have been exposed, making Tri and Tet meshing more robust and adaptable than ever before. Read the details here.

Picking entities in the graphics window can be challenging. The new Extended Selection Dialog and filter manager will allow users to create their own selection filters using Python.


Solid Modeler Upgrade

Post-Meshing Button

A major release signifies an upgrade to the ACIS™ solid modeling engine. Trelis 16x used ACIS 25. As such, Trelis cannot guarantee geometry ids are consistent between Trelis 15x and Trelis 16x. Users with journal files that use explicit id numbers may need to modify those files to use ids from the ACIS 25 space or ID-Less referencing to geometric entities. Please see the documentation for details.

On the right-side of the top-level mode buttons is the "Post Meshing Tool Launch" button. A typical use is to launch an external, executable program.

Trelis now includes an additional field to the dialog that configures the launch. The dialog is found under Tools/Options/Post Meshing.

In addition to specifying the executable’s location, name, and input arguments, users may also specify a script which will be run before launching the executable. A use may include exporting the model to a known location.

Boundary Layer Improvements

Surface Overlap Check Tool

Trelis CFD/Pro 16.0 includes several improvements to boundary layers. All improvements are based on feedback from our Trelis CFD users. Details for some of the improvements can be found here.

Trelis cannot produce a contiguous mesh on a model that contains overlapping surfaces. Trelis now includes a button, located on the top tool bar, that quickly locates overlapping surfaces. The middle button, shown in this image and circled in yellow, is the "Locate Overlapping Surfaces in the Model" tool.

New Quality Tool on Properties Page

The Quality Tool on the properties page will now respect the quality defaults in the options panel. In other words, all of the quality metrics selected in the options panel will be executed when the user clicks on the Quality Tool.

Mesh Scaling Improvements

Mesh Scaling has been significantly improved over the version in Trelis 15.x. Mesh scaling globally refines or coarsens the current hexahedral mesh in Trelis based upon a multiplier. A multiplier of 2.0 will result in approximately double the number of hexes in the model. A multiplier of 0.75 will reduce the number of hexes by approximately 25%. (Image courtesy of Sandia National Labs)

Hex Cleanup

A new hex cleanup capability has been added to Trelis 16.0. This capability improves mesh quality when the mesh contains columns of "high-angle" hexes on volume boundaries. A combination of column operations is done to add three additional columns of hexes to mitigate the high angle. (Image courtesy of Sandia National Labs)

New Entity Align Command Panel

An Align (3 Step) command panel has been added to the GUI making geometry alignment much easier and more intuitive. The command panel is available for volumes, surfaces, curves, and vertices.

15.4.3 New Features in Trelis 16.3

Many updates and enhancements from the Cubit core have been integrated into Trelis 16.3. The development team at Coreform have been focused on making Trelis easier to use and more customizable. We will continue to create core functionality then expose it through the powerful Python interface so users can build their own workflows and user experiences. In addition, users can share their customized workflows with others anywhere.

Customization - Toolbars

Geometry Command Panel Button Hierarchy Change

The Custom Toolbar architecture has been completely redone. Users can create custom tools as in previous versions of Trelis, but the toolbars can now be used as workflow managers. Toolbars may include standard buttons, journal files, Python scripts, and command panels. Toolbars and workflows may be exported and imported.

The button hierarchy for the Geometry command panels is now action based rather than entity based. Other button hierarchies have been modified with a focus on ease of use.

New Context Menus for Boundary Conditions

New Look Icons

Context menus for list, draw, and draw add have been added to boundary condition objects in the model tree.

All of the icons have been refreshed, making the look of the GUI consistent and easier to understand.

General Improvements

New APREPRO Functions

Many improvements for robustness, memory use, speed, and results have been added to.

  • Mesh Scaling

  • Paving (quadrilateral meshing)

  • Triangle Meshing

  • Graphics

  • Patran Export

  • Abaqus Import

  • Geometry creation using Lofting

  • Mesh Power Tool

New APREPRO functions include:

  • NumBlocks

  • NumSidesets

  • NumNodesets

15.4.4 New Features in 16.4

As with all other releases, updates and enhancements from the Cubit core have been integrated into this version of Trelis. The Coreform team continues to make Trelis easier to use and more robust. Our technology partners, including http://www.distene.com and http://www.spatial.com, also continue to make their respective contributions better, faster, and more robust. Release Notes for Trelis 17 can be found http://coreform.com/trelisnew#release.

Enhanced Python Script Tab

Trelis is a command-driven software. At the Python level this is most apparent. The syntax for generating a command is:

cubit.cmd("enter a command string here")

Trelis 17 includes a new field where users can enter the "raw" command, press enter, and the Python script will be generated and sent. This feature can be toggled on and off from the Tools/Layout Options Dialog, partially shown at the left.

Improved Mesh Import Dialog

The Mesh Import dialog has been streamlined and is easier to understand and use. Users may import Mesh Geometry, Free Mesh, or Lite [Exodus] meshes. Lite meshes are explained below.

Lite [Exodus] Meshes

Trelis supports Lite, or light-weight, Exodus meshes. These meshes are loaded very quickly and are easy and efficient to manipulate in the graphics window. An explanation of Lite meshes is found in the documentation.

Import/Export Support for Gambit Neutral Files

Import Gambit Neutral Files fromthe File/Import dialog.

Export Gambit Neutral Files fromthe File/Export dialog.

Decomposition Suggestions as a Command Panel

One of the most popular tools in the ITEM tool is the decomposition suggestions tools. This tool remains in ITEM but has been replicated as a command panel for easy access. Find this tool in the Command Panels under Geometry/Webcut/Volumes/Decomposition Suggestions.

Source/Target Suggestions as a Command Panel

Another popular tool in ITEM is the Source/Target Suggestions tool. This tool has been replicated in the Command Panels and can be found under Mesh/Volume/Mesh/Suggest Source/Target.

Import/Export Toolbuttons Added to Toolbar

Tool buttons to launch the Import and Export dialogs have been added to the main toolbar.

15.4.5 New Features in 16.5

As with all other releases, updates and enhancements from the Cubit core have been integrated into this version of Trelis. The Coreform team continues to make Trelis easier to use and more robust. Our technology partners, including http://www.distene.com and http://www.spatial.com, also continue to make their respective contributions better, faster, and more robust. Release Notes for Trelis 16.5 can be found http://coreform.com/trelisnew#release.

Updated Meshing Algorithms

Triangle Meshing Improvements

  • The self-intersection prevention algorithm for triangle meshes has been enhanced, especially on curved thin areas.

  • Mesh quality has been improved when sizing is chaotic

  • Volume gradation performance has improved

  • More robust triangle meshing of discrete geometry

Tetrahedral Meshing Improvements

  • The gradation, minimum size, and maximum size are handled better making it possible to generate a coarser mesh than previous versions as the gradation increases.

  • Improved memory management decreasing crashes

Enhanced Graphics Pipeline Performance

The graphics subsystem was upgraded to VTK 8.0, using OpenGL2. Rendering speed has increased anywhere from 4 times to 100 times, depending on the model being rendered. Memory usage is roughly the same as in previous versions of Trelis, although memory management has improved.

Other Important Changes

  • Added ability to add a force on a node or face

  • When selecting a material on the model tree, users can now assign that material to a block or edit the material using a context menu.

  • Added ability to perform a quality check on a block.

  • When importing or exporting Gambit Neutral File, users must now use the keyword ’neutral’. Otherwise, a .dbs file will be assumed.

  • Users can now stitch surfaces that contain composites

  • The ITEM Wizard is now its own docking window.

  • The ’create surface from curves’ command is more tolerant of sloppy geometry.

  • Added a new function the CubitInterface. double evaluate_exterior_angle_at_curve( int curve_id, int volume_id)

Lite Mesh Enhancements

’Lite’ mesh elements introduced in the previous version have some additional functionality, including:

  • When hitting ’n’ in the graphics window the listing now includes Lite elements

  • More functions for highlighting and drawing Lite elements

  • The Model Tree icon will change for blocks, sidesets, and nodesets when Lite elements are contained

Remove Blunt Tangencies

A new command and command panel was added to remove blunt tangencies. Read more detail about the function here. Command: blunt tangency vertex <id> [remove_material] [angle <degrees=45>] [depth <value> ] [preview] Command Panel:

This command works on areas where tangencies cause very small elements and small time steps.

Easy Access to More Power Tools

The ITEM Wizard contains many tools that are useful for defeaturing models or otherwise preparing a model for meshing. The most popular tools have been exposed as command panels making them easier to access and enabling their use in a custom tool bar.

  • Remove Small Features

  • Check Meshability

  • Check for Blend Surfaces

  • Manage Gaps and Overlaps

  • Manage Imprint and Merge

  • Force a Sweep

  • Suggest Source and Target Sweep Surfaces

  • Suggest Decomposition Solutions

Figure 626: