Balance holes are organized in rows, each defining a circumferential distribution of holes.

For each row, design parameters are available to define the size, position and number of holes.

The radial position r is referenced to the hub surface. Consequently changes to the radial direction γR do not modify the hole center position on the hub surface.

The circumferential position φ specifies the relative position of the hole center between the profiles of adjacent main blades.

The circumferential direction γT is referenced to the direction of rotation. Positive values incline the hole axis in the direction of rotation relative to the hole center position on the hub surface.

Balance holes are not present in each segment!

A rotationally symmetric 3D segment cannot be generated because the number of holes per row is smaller than the number of periodic sectors in the full 360° geometry.

This information is provided for reference only and does not require any parameter changes.

Balance holes intersect each other!

Balance holes of different rows intersect each other.

To avoid unintended hole intersections, modify the parameters of one or more rows.

Balance hole intersects itself!

Intersecting balance holes within the same row result in a split hub material solid.

Reduce hole diameter or number of holes.

Increase radial position.

Balance hole intersects blade!

Intersections of balance holes with blade surfaces are not supported. Intersections with blade fillet surfaces are permitted.

Reduce hole diameter.

Change circumferential position.

Invalid interface between balance hole and flow path!

The balance holes do not provide a full connection to the flow path.

Reduce hole diameter.

Change radial position.

Invalid interface between balance hole and secondary flow path!

The balance holes do not provide a full connection to the secondary flow path.

Reduce hole diameter.

Change radial position or radial direction.

Change casing contour.