Mesh

The Mesh manager node allows you to define and control the volumetric discretization of the computational domain.

The Electronics Cooling Toolset generates predominantly hexahedral cells in the volume mesh with prism shaped cells next to the walls. The prismatic cells are created in the fluid domain only and allow the solver to accurately capture near-wall flow and heat transfer. An integrated mesh refinement procedure automatically refines the mesh to capture complex features. The refinement takes place on surfaces that are in close proximity to one another, strongly curved, or relatively small when compared to the rest of the surfaces.

The Electronics Cooling Toolset provides three types of mesh settings:

  • Global settings—apply to all QuickParts and QuickPart Surfaces.
  • Surface Controls—are valid for specific QuickPart Surfaces and override the global settings.
  • Volume Controls—are valid for the volume contained within a QuickPart or a Construction Geometry and override the global settings.

The Custom Control—Surface Control or Volume Control—that produces the smallest cell size takes precedence.

Mesh Settings

The following properties define the global characteristics of the mesh:

Automatically compute Base and Minimum Sizes Controls the definition of the base size and the minimum cell size. By default the Electronics Cooling Toolset calculates these values automatically, where the calculation is based on the geometric scales of your electronics device. Deactivating this option allows you specify cell sizes directly.
Base Size Specifies a characteristic dimension of the model. The minimum cell size and the fluid boundary layer thickness can be set as a percentage of this value. It also defines the target cell size on the surfaces.
Minimum Size Specifies the lower limit of cell size.

Decreasing this value allows more refinement in areas where the mesher is trying to capture complex features. However, an extensive refinement increases the CPU time and size of the mesh.

Mesh Refinement Controls the refinement of the mesh in order to accurately capture complex geometrical features.
Surface Proximity
When activated, allows mesh refinement on surfaces that are close to one another. It determines the cell size as the distance between surfaces across a gap divided by the specified value.
Increasing this value produces more cells in gaps.
Pts around Circle
When activated, allows mesh refinement on curved surfaces. The specified value determines the number of cells that are used to define a 360 degree cylindrical surface.
Increasing the value increases the relative refinement of cells next to curved surfaces. For components that have a relatively small diameter when compared to the rest of the mesh region, decrease this value to avoid over-refinement.
Edge Proximity
When activated, allows mesh refinement on relatively small surfaces. It determines the cell size as the distance between opposite perimeter edges across a surface divided by the specified value.
Increasing this value produces more cells on small surfaces.
NoteIf a QuickPart is composed of one QuickPart Surface only, applying edge proximity has no effect. You must split the QuickPart Surface first to get perimeter edges accordingly. See Splitting a QuickPart Surface.
Fluid Boundary Layer Controls the prismatic mesh for the fluid boundary layer.
Total Thickness
Specifies the total overall thickness of the prism layer.
Number of Layers
Specifies the number of cell layers that are generated within the prism layer.
Stretching
Specifies the target growth rate of successive prism layers away from the wall.

Custom Mesh Settings

The following properties define the customized characteristics of the mesh:

Properties Surface Control Volume Control
Name Specifies the name of the Custom Control under which it is stored in the tree.
Surfaces Specifies the QuickPart Surfaces that define the surfaces of mesh customization.
Parts Specifies the Construction Geometries that define the volumetric zone of mesh customization.
Target Size Specifies the target cell size in the volumetric zone of mesh customization.
Minimum Size As for Mesh Settings.
Fluid Boundary Layer As for Mesh Settings.

Options

The following options control the specification of various properties within the global and customized settings:

Percentage of Base Specifies the reference value as percentage of the base size that is defined within the Edit Mesh Settings dialog. The advantage of a relative size specification is that changing the base size scales both global and object specific sizes.
Absolute Size Specifies the reference value as absolute in any of the allowable length units.
Use Parent Value Applies the global value to the mesh setting as defined in the Edit Mesh Settings dialog.
Specify Custom Value Applies a customized value to the mesh setting.
Disable Does not apply prismatic cell layers to the surface.

Mesh Right-Click Actions

The following action is available when you right-click the Mesh manager node:

Edit Mesh Settings
Allows you to specify the global Mesh Settings.

The following action is available when you right-click the Mesh > Custom Controls node:

New > [Type]
Creates a new custom control. The following types are available:
  • Surface Control
  • Volume Control
A separate Edit tab opens and allows you to set the Custom Mesh Settings of the respective custom control.

The following specific actions are available when you right-click a particular custom control:

Highlight
Highlights the respective surfaces or parts of the selected custom control in the Graphics window.