Impeller > CFD setup

► IMPELLER | CFD setup

Extension, RSI connection

Description can be found in the topic Virtual geometry.

Segment

The segment is the flow passage around a single blade and represents the smallest rotation-symmetric part of the impeller.

The middle of blade pressure and suction side of two neighboring main blades forms the segment boundary. These periodic surfaces are extended into the inlet and outlet area.

Blade projection

Blade projection can be used for meshing purposes.

In case of an unshrouded impeller the outer blade profile is projected onto the casing.
If an Extension exists, the blade trailing edge is projected onto the Rotor-Stator-Interface (RSI).

Possible warnings

Problem	Possible solutions
Generation of segment may fail due to meridional contour.
The angle between rotation axis and hub contour is too small (lower than 0.1 degree).	Set a value for hub diameter higher than zero or round the hub contour to avoid a geometry with needle form.

Problem

Possible solutions

Generation of segment may fail due to meridional contour.

The angle between rotation axis and hub contour is too small (lower than 0.1 degree).

Set a value for hub diameter higher than zero or round the hub contour to avoid a geometry with needle form.