Trimmed Cell Mesher Reference

The trimmed cell template mesh is aligned with the global cartesian laboratory coordinate system by default. If the imported surface is not aligned to this coordinate system, then it can be advantageous to realign the template using a user-defined cartesian coordinate system instead. Once a new coordinate system has been defined, it can be selected using the Coordinate System pull-down menu in the Properties dialog:

The trimmed cell mesh is now generated based on the new local coordinate system instead of the global one.

The trimmed cell mesh alignment option is turned off by default, meaning that the template mesh is centered and aligned based on the global bounds and model alignment in the specified coordinate system.

In certain circumstances, such as free surface calculations, it is desirable to align a plane of mesh faces with a physical plane corresponding to a salient feature such as an initial free surface. Such alignment is done, not only in order to make the physical model setup and initialization easier, but also to improve accuracy. Turning the Perform mesh alignment option on allows the mesh location coordinates to be specified for the chosen trimmed cell coordinate system, so that the mesh lines coincide with that location:

With the perform mesh alignment option turned on, the Mesh Alignment Location node under Default Controls can be used to specify a location in the currently specified coordinate system. The trimmed cell mesh is then aligned so that this location is on a cell corner vertex in the resultant mesh. Selecting the Mesh Alignment Location node allows the mesh alignment values to be set:

The Location coordinate can be specified in any of the allowable units. If mesh alignment is only required in one direction, leave the other two location coordinate values set to 0. The current location of the grid alignment point is highlighted in the scene using a circular ball once the Mesh Alignment Location has been set.

The Size dependent growth rates property determines the growth rate options that are used to control the refinement next to surfaces and in the core mesh. Two options are provided:

• All cells
• Small and large cells

By default, the Size dependent growth rates is set to All Cells