### 5.2.3. Controls Tab

Figure 5.8: Control Input Tab

Throughflow controls:

Max iterations, Error tolerance and Relaxation factor.

The design and analysis calculations are made using an iterative throughflow solver. Max iterations, Error tolerance and Relaxation factor control the maximum number of attempted iterations, the relative error in mass balance and the damping between iterations respectively. The default solver settings are robust and accurate and should only be adjusted where difficulties are encountered and modification of the input data does not help.

Design Iterations (available only from the Design cell):

Inner loop iterations and Outer loop iterations.

In the design calculation, the throughflow code is run multiple times in order to achieve the required duty. The inner loop makes adjustments to the blade angles and requested pressure rise in order to achieve the duty, while the outer loop updates the efficiency estimate and reruns both the meanline and throughflow calculations in order to achieve a consistent result.

The process is illustrated by Figure 5.9: Design Calculation Flowchart.

Figure 5.9: Design Calculation Flowchart

Export options

Blade to export (BladeGen) is used to select the blade row to export when exporting to BladeGen (BladeGen can only model a single blade row at a time.). By contrast, when exporting to BladeEditor, all blade rows are always exported.

Layers to export settings control which spanwise layers are exported. Although the throughflow calculation uses geometry on 5 spanwise layers, the number of layers used to create the blade model can be reduced by clearing the check boxes for any of the 3 internal layers. The hub and shroud layers are mandatory.

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