Building the Mesh

This section describes the step-by-step procedure for preparing the mesh for the rotating machinery. The mesh is created using the General Mesher.

Inlet and Volute Meshes

Select General Mesher in the Mesh Panel.
Select CAD Surfaces inlet_inlet , inlet_mgi, inlet_wall, volute_mgi, volute_outlet, volute_rotating_walls and volute_wall in the Geometric Entities Panel and click Add Surfaces icon for CAD Surfaces in the Properties Panel.
Ensure Relative to All CAD Surfaces is selected under Cell Size Specification.
Enter Maximum Cell Size as 0.01, Minimum Cell Size as 0.001 and Cell Size on Surfaces as 0.005 in the Properties Panel.
Click Create Mesh. A new mesh general mesh is created under Built Meshes in the Geometric Entities Panel. Rename it as inlet_volute.
The meshed volumes inlet and volute are generated under Volumes.

Figure 11.336 - Inlet and Volute mesh settings

Rotor Chamber Mesh

Select General Mesher in the Mesh Panel.
Select CAD Surfaces rotor_blades, rotor_bot, rotor_inlet, rotor_mgi and rotor_top in the Geometric Entities Panel and click Add Surfaces icon for CAD Surfaces in the Properties Panel.
Enter rotor in Mesh Name in the Properties Panel.
Ensure Relative to All CAD Surfaces is selected for Cell Size Specification.
Enter Maximum Cell Size as 0.01, Minimum Cell Size as 0.0005 and Cell Size on Surfaces as 0.005.
Click Create Mesh. A new mesh rotor is created under Built Meshes in the Geometric Entities Panel.
The meshed volume rotor is generated under Volumes.

Figure 11.337 - Rotor mesh settings

´	Note: The mesh can be edited/ replaced by selecting it under Built Meshes, and modify the mesh parameters in the Properties Panel. Click Create Mesh to reflect the changes.

The mesh created for the fluid domain is shown below.

Figure 11.338 - Inlet mesh

Figure 11.339 - Rotor mesh

Figure 11.340 - Volute mesh

Create interfaces

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

To connect the inlet and rotor chamber:

Select Boundaries entities inlet_mgi and rotor_inlet (see, Figure 11.341) from the Boundaries list under Volumes in the Geometric Entities Panel .
Click Connect Selected Boundaries via MGI icon to create the interface between the inlet and the rotor chamber.

A new entity MGI01 is created under Mismatched Grid Interfaces in Volumes (see, Figure 11.342).

To connect the rotor chamber and volute:

Select Boundaries entities rotor_mgi and volute_mgi from the Boundaries list under Volumes in the Geometric Entities Panel.
Click Connect Selected Boundaries via MGI icon to create the interface between the rotor chamber and the volute.

A new entity MGI02 is created under Mismatched Grid Interfaces in Volumes (see, Figure 11.342).

Figure 11.341 - Connecting inlet to rotor chamber

Figure 11.342 - 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.