About the Mesh

The mesh divides a solid body into many cells (or elements). You can modify the typical size of all elements throughout the mesh, and you can modify the size of elements at important boundary locations. These changes enable you to refine the results values or to reduce computation time.

See Also
Setting Up the Mesh

Within each element in your mesh, the simulation considers material, temperature, and flow behavior to be constant. By creating a more refined mesh with smaller cells, the simulation can predict more detailed results at the expense of longer simulation times.

Having a more refined mesh can also enable you to capture how temperature and flow conditions change within a body. For example, using a single mesh cell to represent flow at a narrow gate will cause the simulation to approximate the flow conditions in the gate as uniform, whereas using a more refined mesh with five or more cells through the cross section of the gate will allow the simulation to more correctly capture the spatial gradients in velocity and temperature that exist in this critical location.

Modifying the mesh setup controls is optional. By default, the computational mesh is not displayed, and it is generated automatically when you execute your first simulation step. You can separately control the mesh refinement of the plastic parts, coolant parts, and virtual mold. You can also manually execute mesh generation and inspect the resulting mesh before proceeding to run a simulation.

Separate controls are available for meshing of the plastic parts, the coolant parts, and the virtual mold.

Cavity
The cavity controls are applied to parts through which plastic flows. The mesh here utilizes a number of thin boundary layer elements near the cavity walls, with larger elements toward the center of the cavity thickness where conditions are more uniform. This approach allows more accurate resolution of temperature and solidification effects that vary through the thickness of the part, because the surface layers freeze while the central layers continue to flow. For a simple part of uniform thickness, the default mesh parameters are selected to create five elements through the thickness of the part, which is a reasonable balance of accuracy and computational cost.
Coolant parts
The coolant parts do not require boundary layer mesh refinement because coolant flow conditions are typically turbulent, resulting in more uniform conditions through the cross section of the cooling channel. A single mesh size control is used for these parts.
Virtual Mold
The virtual mold mesh serves to conduct heat between the plastic and coolant parts. This mesh is automatically refined to match the meshes of these parts and can typically be allowed to become more coarse toward the outer surfaces of the mold where temperature gradients are low.