37.8. Step 5: Run Transient Trials

  1. On the Parameters and optimization panel State-space tab under Solution type, select Transient.

  2. Enter 5.0 W for the Input object power.

  3. Next to Transient setup, click Set to automatically set the time step size and duration.

    Note:  The automatic Set option sets simulation duration of 10,000 seconds to make sure that the system reaches a steady state. This also uses smaller time step size at the start to capture in initial transient behavior. Edit option can be used to change these settings.

  4. Next to Steady state solution, click Select to open the File selection dialog and browse for the steady-state.fdat file.

    Note:  Icepak restarts from a full data steady state solution and runs a transient energy only solution (no flow).

    Note:  Icepak generates step response data.

  5. Enter a Trial ID prefix and click Run trials.

    Figure 37.9: Set Up Transient Trials

    Set Up Transient Trials


    Note:  For every input, Icepak runs one solution. For every output, Icepak creates step response curves within each solution.

    Note:  The concurrent solving ability in Icepak is not used for these runs.

  6. Note the trials residuals in the images below. Ensure that the solution is converged. The temperature monitor point curves must be flat at the end.

    Figure 37.10: Transient Trials Residuals

    Transient Trials Residuals

    Note:  Icepak generates 16 monitor files, which are the step responses of the system. These (.out) files are saved in the project directory within a directory named Twin BuilderFiles. The following files are generated:

    • [InputObjectName].[OutputObjectName].out

    • [SolutionID].gif

    • [SolutionID].simpinfo

    • InputPortNames.txt

    • InputStepInputValues.txt

    This completes the generation of the step response data using Icepak. In the next section, we will use the step response data to create a state-space model in Twin Builder.