Building the Mesh

This section describes the step-by-step procedure for preparing the mesh for the mixing tank model that contains stator and rotor. The mesh is created using the General Mesher.

Rotor

Select General Mesher in the Mesh Panel.
Select CAD Surfaces mixingtank_rotor, mixingtank_rotor_mgi_statorbot, mixingtank_rotor_mgi_statorside and mixingtank_rotor_mgi_statortop in the Geometric Entities Panel.
Enter Maximum Cell Size as 0.01, Minimum Cell Size as 0.001, Cell Size on Surfaces as 0.01 in the Properties Panel.
Click Create Mesh. A new mesh mixingtank_rotor is created under Built Meshes in the Geometric Entities Panel.
To refine the interfaces, click mixingtank_rotor from Built Meshes and select mixingtank_rotor_mgi_statorside from CAD Surfaces.
Select User Input from Cell Size on Boundaries drop-down list and enter 0.005 for Size in the Properties Panel. Click Create Mesh to update mixingtank_rotor under Built Meshes in the Geometric Entities Panel.
The meshed volume mixingtank_rotor is generated under Volumes.

Figure 11.283 - Rotor mesh settings

Stator

Select General Mesher in the Mesh Panel.
Select CAD Surfaces mixingtank_stator_mgi_rotorbot, mixingtank_stator_mgi_rotorside, mixingtank_stator_mgi_rotortop, mixingtank_stator_shaft and mixingtank_stator_wall in the Geometric Entities Panel.
Enter Maximum Cell Size as 0.01, Minimum Cell Size as 0.001 and Cell Size on Surfaces as 0.01 in the Properties Panel.
Click Create Mesh. A new mesh mixingtank_stator is created under Built Meshes in the Geometric Entities Panel.
To refine the interfaces, click mixingtank_rotor from Built Meshes and select mixingtank_rotor_mgi_statorside from CAD Surfaces.
Select User Input from Cell Size on Boundaries drop-down list and enter 0.005 for Size in the Properties Panel. Click Create Mesh to update mixingtank_rotor under Built Meshes in the Geometric Entities Panel.
The meshed volume mixingtank_stator is generated under Volumes.

Figure 11.284 - Stator mesh settings

The mesh created for the fluid domain is shown below.

Figure 11.285 - Full Mesh view

Figure 11.286 - Cross-sectional view

Create interfaces

In this section, the Mismatched Grid Interfaces (MGI) are generated between boundaries.

The steps to create the MGI is as follows:

Geometric Entities Panel > Volumes > Boundaries, select entities shown under boundaries (see, Table 11.12).
Click Connect Selected Boundaries via MGI icon to create the MGI entities (see, Figure 11.287).

A group display of entities can be viewed using the Group Entities by Volumes/Types icon at Geometric Entities Panel toolbar.

Connecting interfaces	Boundaries	Entity
Stator Bottom and Rotor Bottom	mixingtank_stator_mgi_rotorbot, mixingtank_rotor_mgi_statorbot	MGI01
Stator Side and Rotor Side	mixingtank_stator_mgi_rotorside, mixingtank_rotor_mgi_statorside	MGI02
Stator Top and Rotor Top	mixingtank_stator_mgi_rotortop, mixingtank_rotor_mgi_statortop	MGI03

Table 11.12 - Creating interfaces

The new entities are created under MGI in Volumes (see, Figure 11.288).

Figure 11.287 - Connecting rotor and stator bottom

Figure 11.288 - Created interfaces

Note: If MGIs are created by connecting the wrong boundaries, delete the created MGIs by clicking on Delete Selected Geometric Entity icon and then recreate the MGIs.