### 6.5.1. Time Transformation: Workflow Requirements

The basic procedure for setting up a Transient Blade Row model is outlined in Setting up a Transient Blade Row Model. When your simulation involves the Time Transformation model, your workflow should include the following steps:

- Ensure that the pitch ratio between adjacent components is within the proper range by appropriately adjusting the number of blades in each component. The proper range is described in Time Transformation.

- Those transient rotor stator interfaces not referenced by a disturbance will be treated with the Profile Transformation method.

- You can model only a single stage. As a result, there must be exactly one domain interface between two time transformed domains.

- Based on the case you are working on, for a given domain, add one disturbance to the list of disturbances.

- Ensure that the relative speed associate with the disturbance is not zero.

Note: When multiple Time Transformation instances are used, the solver will attempt to compute the streamwise scale equation(*). In cases where the machine contains more than one inlet or outlet (for example, due to the presence of injection holes or cooling grooves) you must manually specify the main inlet and/or main outlet of the machine; that is done by entering the following lines of CCL:

    TRANSIENT BLADE ROW MODELS:
     Inflow Boundary = <main inlet name>
     Outflow Boundary = <main outlet name>
     Option = Time Transformation
     .
     .
     .
    END

Failure to specify the main inlet and/or outlet will result in the solver issuing the following message:

    Multiple Inlets and/or Openings were detected for this multi-disturbance Time Transformation
    simulation. Please specify one inlet as streamwise scale specified boundary condition region.

(*) The streamwise scale equation is used to compute the streamwise location of the machine components.

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