### 8.2.2. Geometry Tab

Figure 8.2: Geometry Tab

This tab contains all the required geometric input data in the Impeller frame.

Frame 1: Diameters

This frame contains the following data items:

- Shroud exit/inlet radius ratio. This is the ratio of the exducer shroud radius to the impeller inlet radius.

- Hub exit/inlet radius ratio. This is the ratio of the exducer hub radius to the impeller inlet radius.

Frame 2: Vanes

This frame contains the following data items:

- Number of vanes.

- Mean vane thickness at exit.

- Vane roughness (k). The Vane roughness is only available when using the `Suhrmann` stage efficiency correlation and is otherwise disabled. There are two options:

  - `Cast finish` ()

  - `Machined finish` ()

- Spanwise distribution can be set to `Radial` or `General`. If it is set to `Radial`, then, if the vane geometry is exported to BladeEditor or BladeGen, all camberlines will have the same theta value at any given axial coordinate. An example of a radial element blade is shown in Figure 10.5: Contour plot of theta (θ) versus radial (R) and axial (Z) coordinates on a blade defined with `Radial Element` .

Frame 3: Axial length

There are two options:

- Correlation. The impeller axial length will be estimated by a correlation.

- Specify. You must specify the Length/diameter as a percentage.

Frame 4: Tip clearance

There are two option:

- Tip clearance/vane inlet height. This is the tip clearance expressed as a ratio

- Tip clearance. This is the tip clearance specified directly.

Release 18.2 - © ANSYS, Inc. All rights reserved.