Transient Solution Data

For transient solutions, Simcenter STAR-CCM+ provides the simulation history file (.simh) to which you can save selected data while a simulation is running. After the simulation completes, you can load this file and query its states for post-processing.

Simulation history files are designed to work with the simulation (.sim) file that created them; simulation history files do not work with different or empty simulation files.

In addition to the solution data, each simulation history file can contain a copy of the volume mesh, the standalone boundary surfaces, or both. When recording solution history, the mesh is only written when it changes. If only the vertex coordinates change for the same mesh connectivity, such as during morphing or rigid body motion, only the modified coordinate array is written in the subsequent states. This behavior is true for recorded snapshots and automatic recording to a simulation history file.

In the simulation tree, you add a solution history node within Solution Histories for each .simh file that you wish to write. You can control the choice of functions, file location, and frequency of writing. No solution settings, such as solver parameters, are contained in this file.

To access the data that is stored within a simulation history file, use a solution view. Solution views are located within the Solution Views manager node, and you can create additional ones. You can visualize the data in a solution view in the following ways:

  • Create and view snapshots of the current solution in steady state simulations, which are useful for comparing the results between different design iterations.
  • Animate the recorded solution data and record this animation to file. Alternatively, build the animation of the scene by exporting to an MP4 file (see Animating Objects in a Scene) or setting up a screenplay animation (see Animating Transient Data).
  • Use recorded solution data in reports and plots.

Information from the simulation history file can be used to annotate scenes to display the iteration number, the solution time, and the time step of the displayed state.

Moving or deleting the simulation history file breaks the link between it and the simulation file. Any scenes that display data from the simulation history file are not rendered. If the link between the simulation history file and the simulation file is broken, you can re-establish it by right-clicking on the Solution Histories node and selecting Load. You can then navigate to the simulation history file and load it into the simulation.

If you are only concerned to observe solution progress in a scene without setting up a simulation history file, you can quickly obtain a movie file from a scene with the following steps:

  1. Set the scene to export every time-step to an MP4. For details, see Saving Scene Images to File.
  2. Run the simulation, perhaps on a cluster.
  3. View the resulting MP4 file to examine the simulation results.