Preparing for Flow Solution Analysis

Preparing analysis (post-processing) objects before running the flow simulation allows you to track the simulation progress while it runs. Planning ahead is particularly important for unsteady simulations if you want to store transient solution data.

To prepare for post-processing:
  1. Set up scenes that visualize representative solution variables.
    For example, set up a vector scene for velocity and a scalar scene for pressure or Mach number. Use plane sections to cut through the solution domain and visualize solution quantities inside the flow domain. To follow the flow path, you can add streamlines to the scenes. Streamlines represents the path of massless particles through the flow.

    For more information on the field functions that are available to visualize the solution, see Flow Field Functions Reference.

  2. Set up reports, monitors, and plots for solution analysis and to judge convergence.
    For example, set up reports that monitor the pressure or Mach number at specific points or on certain planes. For judging convergence, care should be taken in the choice of location, especially for steady-state calculations. Ideally, choose a sensitive region of the flow where the approach to the steady state is likely to be slowest—for example a recirculation zone. In transient flow calculations, the information has a different significance and so other criteria for choosing the location can apply. For example, you can choose a location so as to confirm an expected periodic behaviour in the flow variables.

    For internal flow simulations, you can set up a report to monitor the mass flowrate through a boundary or an interface—see Reporting Mass Flow Rate. Monitoring the mass conservation in the simulation domain can also help in assessing solution convergence—see Reporting Overall Mass Conservation.

    For external aerodynamics applications, you can monitor lift and drag coefficients to determine when the analysis has converged. See Reporting Lift and Drag Coefficients.

  3. For unsteady simulations, if you want to save selected data while the simulation is running, you can create a solution history file. After the simulation completes, you can load this file and query its states for post-processing. You can also create animations that show solution behavior over time. For more information, see Recording Transient Solution Data.