Leakages

This section explains the settings for specifying the leakages in the swash plate piston chamber. Leakages can be modelled using the Swash Plate Piston template as follows.

The parameters related to swash plate piston chamber leakages can be accessed by setting the Setup Options to Advanced Mode.

Side Leakage Gap

This corresponds to the height of axial gap between the piston pumping chambers and valve plate. Specify a real number for giving the gap height in m.

Gap Inner Radius

This corresponds to the inner radius of the Side Leakage Gap (axial gap). This radius is taken relative to the Rotational Axis Vector. Specify a real number for giving the inner radius in m.

Gap Outer Radius

This corresponds to the outer radius of the Side Leakage Gap (axial gap). This radius is taken relative to the Rotational Axis Vector. Specify a real number for giving the inner radius in m.

Figure 6.408 - Side leakage gap-Swashplate

Note: A non-zero value of Side Leakage Gap will cause this gap volume to be created under Volumes. A gap with thickness of Side Leakage Gap, is added between the valve plate and cylinder cap and automatically connected to the piston cap volume via MGI.

Gap Layer Limit

Allows to limit number of mesh layers under Limited to 5 Layers option and allows to add more than 5 mesh layers in gaps under Unlimited option, as shown in Figure 6.409.

This option gives user additional control for Number of Layers in Gap, as shown in Figure 6.409. When the Limited to 5 Layers option (the default option) is selected, user can only set up to 5 layers for Number of Layers in Gap. When Unlimited option is selected, user can set any number of layers for Number of Layers in Gap.

Figure 6.409 - Gap Layer Limit

Gap Mesh Size

Allows the user to control the mesh cell size and distribution in the Side Leakage Gap (axial gap).

The Gap Mesh Size has the following options:

Default: Uses the default mesh settings of the template in the radial and tangential directions for the leakage gap..
User Input: Allows the user to specify the number of cells in the radial and tangential directions using the options No. of Gap Cells in Radial Dir and No. of Gap Cells in Tangential Dir respectively.

Figure 6.410 - Gap mesh size-Swashplate

Gap Position

This allows the user to select the position of Side Leakage Gap (axial gap) between the piston pumping chambers and the valve plate.. The options to specify the Gap Position are as follow:

Allow Small Overlap: The cylinder cap volume of piston pumping chamber is shrunk to accommodate the gap, with a quarter of a cell overlap at the boundaries. This option can be used when there is no gap between the piston pumping chambers and valve plate in CAD.
Shrink Rotor: The cylinder cap volume of piston pumping chamber is shrunk as needed to accommodate the gap with no overlap at the boundaries. This option is used when there is no gap between the piston pumping chambers and valve plate in CAD.
Gap Outside Rotor: The pumping chamber is not shrunk and the gap is placed between the piston pumping chambers and valve plate. This option requires that space for the gap has already been created in CAD.

Figure 6.411 - Gap position-Swashplate