Conditions

This section explains the conditions related to the boundaries and the volume in a rolling piston simulation.

The conditions for a desired boundary are accessed as follows:

Geometric Entities Panel > Boundaries > [Desired boundary]

Properties Panel > Model Tab > Rolling Piston> [Desired options]

Figure 6.685 - Rolling piston-Conditions

Chamber Wall: This is assigned to the outer boundary of the mesh volume encircling the rotor chamber (chamber wall). It can correspond to a physically solid surface, a fluid interface, or a combination of the two.

Note: This boundary can be a solid surface, a fluid-fluid interface, or a combination of the two (the latter two conditions are achieved via MGI (s)).

Rotor: This is assigned to rotor surfaces. This condition is automatically assigned by rotor template mesher. The rotational properties of the Rotor are set under the global Angular Velocity Definition parameters and displayed in Blue.
Vane: This is assigned to vane surfaces. This is automatically assigned by rotor template mesher.
Vane Tip: This is assigned to vane tip surfaces. This is automatically assigned by rotor template mesher.
Inlet: This specifies an inlet boundary and assigns inlet properties for Flow and all other modules. The default inlet boundary for Rolling Piston module uses a Static Inlet Pressure as the Flow boundary conditions.
Outlet: This specifies an outlet boundary and assigns outlet property for Flow and all other modules. The default outlet boundary for Rolling Piston module uses a Static Outlet Pressure as the Flow boundary conditions.
Rotating Wall: This boundary condition enables setting a rotational velocity on a boundary. This allows specifying an angular velocity (rpm) and an axis of rotation for a selected boundary other than the rotor. This adds rotational sources to the momentum of the fluid (via the Flow module) without displacing the boundary.
Wall: This corresponds to a solid boundary and by default assigns the Wall boundary condition for Flow and other modules.

Note: The default values in each module under the template can be accessed and modified, by using the Extended Mode.

The Rolling Piston template has following parameters assigned to the fluid volumes. The conditions for a desired volume are accessed as follows:

Geometric Entities Panel > Volumes > [Desired Volume]

Properties Panel > Model Tab > Rolling Piston > [Desired options]

The template has conditions which apply to Volumes in the simulation under Rolling Piston module. Each volume may be assigned specific independent volume conditions.

Material: The material properties are provided as a convenience and can also be set individually under the appropriate modules using Extended Mode. The fluids available are Oil, Water, Air and User Defined.
Operating Conditions: The Operating Conditions are provided as a convenience and can also be set individually under the appropriate modules using Extended Mode. The available properties depend on the modules that are active.

Figure 6.686 - Material properties

Output

Primary and Derived variables can be integrated over a selected boundary and stored in the ASCII format file filename_integrals.txt for subsequent Post-Processing. These data can also be displayed real-time in the GUI using the X-Y Plots feature.

The desired output can be activated for a selected boundary in the Model Tab of the Properties Panel. The outputs which can be activated are specified as User Select (Area, Normal).

For the boundaries specified as rotor, the outputs Torque, Power, Revolution Averaged Power are automatically available in the Plot Panel and displayed using X-Y Plots. For more information on outputs, refer Output variables under each module.

When monitoring Points are created as part of the simulation, the output quantities are stored in the ASCII format file filename_points.txt for subsequent Post-Processing.