# Combining Results Files to Obtain a Single Animation

Often a user will run restarts of existing simulations because the solution did not reach steady-state conditions or because the simulation terminated too early. The question then becomes how to combine the original and restart results for a continuous time sequence animation. This document will provide the user with step by step instructions on how to combine data for a continuous animation in both 2-D and 3-D. The example Flow Over A Weir problem, found in the Example library through the FLOW-3D GUI, will be used to demonstrate how to combine results files.

## Creating the Output Files

A results file and several restart files will be created for this demonstration. The simulation will have the following parameters; complete simulation time 3 seconds, restart data at the default frequency of 0.1 seconds for restart data, and pressure as the parameter of interest.

1. From top menu in Graphical User Interface (GUI) select File>Add Example.
2. Select Flow Over A Weir.
3. Select General tab, change finish time to 3 seconds.
4. From top menu select Run Simulation.
5. When the simulation reaches about 1 second, click the Terminate button on the Simulate tab.
1. Add a restart of the previous simulation.
1. Select the Navigator tab.
2. Select the Flow Over A Weir simulation.
3. Select File>Add Restart Simulation from top menu in Graphical User Interface (GUI). Accept the defaults and select ok.
4. When the simulation reaches about 2 second, click the Terminate button on the Simulate tab.
1. Add a restart from a restart simulation.
1. Select the Navigator tab.
2. Select Flow Over A Weir Restart.
3. Select File>Add Restart Simulation from top menu in Graphical User Interface (GUI). Accept the defaults and select ok.
4. Let the simulation run to completion.

## Combining Results for 2-D Animations

The 2-D results can be added together to create a continuous time sequence of results from several restarts. In this example we will look at pressure contours in the x-z plane at y=0.25. The sequence of operations are important in order to produce results starting from t=0 and ending in t=3 seconds.

1. Open Flow Over A Weir Restart Restart results.
1. Select the Navigator tab.
2. Select Flow Over A Weir Restart Restart.
3. Select the Analyze tab>2-D tab.
4. Select the Open Results button.
5. Select flsgrf.Flow_Over_A_Weir_Restart_Restart.
6. Select the x-z radio button under Plane.
7. Move the y sliders to the far left. See Figure 1.

Figure 1: 2-D plot selections.

 Select the Render button. The results will be displayed on the Display tab. Select the Files button on the Display tab. The File options dialog box will open. Select the Create button. ACreate plot file dialog box will open. Assign a title to the plots with an extension of .plt. Example: flowoveraweir2to3.plt Figure 2: File options dialog

Figure 3: Create plot file dialog box.

1. Select the Write button.
2. Select the OK button.
3. Select the Close file button.
4. Select the Quit create button.
1. Open Flow Over A Weir Restart results.
1. Follow the steps 1a.-o. for Flow Over A Weir Restart
2. Open Flow Over A Weir results and append to these results.
1. Follow steps 1a.-i. for Flow Over A Weir.
2. Select Open(append) button.
3. Browse to Flow_Over_A_Weir_Restart directory.
4. Select the saved plot file-flowoveraweir1to2.plt.
5. Repeat steps 3b.-d. to add Flow Over A Weir Restart Restart plots.
6. Select Close from the File options dialog box.

Now you can create your animation.

## Combining Results for 3-D Animations

The 3-D results can be added together to create a continuous time sequence of results from several restarts. In this example we will create an animation of the fluid surface colored by pressure. The sequence of operations are important in order to produce time results starting from t=0 and ending in t=3 seconds.

1. Open Flow Over A Weir results.
1. Select the Navigator tab.
2. Select Flow Over A Weir.
3. Select the Analyze tab>3-D tab.
4. Select the Open Results button .
5. Select flsgrf.Flow_Over_A_Weir.
6. Select the Solid volume radio button under Component iso-surface overlay.
7. Open the time frame sliders so all of the time frames will be rendered.
8. Check Render frames to disk under Iso-surface options.

Figure 4: 3-D plot selections.

1. Select the Render button.
1. Open Flow Over A Weir Restart results and append to Flow Over A Weir results
1. Repeat steps 1a.-h. for Flow Over A Weir Restart.
2. Check Append to existing frames already rendered to disk.
3. Select Flow_Over_A_Weir directory.
4. Select OK. Once this has been selected a check box will appear next to Append to existing frames already rendered to disk.

Figure 5: Appending to existing frames.

1. Select Render. The results file will start from 0 seconds to roughly 2 seconds depending on when the actual termination occurred.

1. Open Flow Over A Weir Restart Restart results and append to Flow Over A Weir results
1. Repeat steps 2 a.-e. for Flow Over A Weir Restart Restart.

Now you can create your animation.

## Review of the Steps

For 2-D animations:

1. Open the final results file with parameters of interest.
2. Render results.
3. Create plots from the Files button.
4. Open the results file in between the final time and initial time if any.
5. Create plots from Files button if necessary.
6. Open the initial time results.
7. Append results files to current result file from the Files button.
8. Create Animation AVI.

For 3-D animations:

1. Open initial results file with parameters of interest.
2. Render the disks to frame.
3. Render results.
4. Open the results file in-between the final time and initial time if any.
5. Render the frames to disk and Append to existing frames already rendered to disk.
6. Browse to original or initial results directory.
7. Render results.
8. Open final time results.
9. Render the disks to frame and Append to existing frames already rendered to disk.
10. Browse to original or initial results.
11. Render results.
12. Create Animation AVI.

## Conclusion

Continuity is key in presenting highly accurate results whether they are 2-D animations or 3-D animations.