Fire Dynamics Simulation Results

Fire dynamics simulation results are stored in the following folder:

..\Project directory\Results\Scenario ID\fds

Where:

• Project directory — the directory where the project file is located;
• Scenario ID — the ID of the scenario in the project.

The scenario ID cannot be defined using the application tools. Therefore, in order to open the folder with the fire dynamics simulation results, you must double-click fire dynamics simulation for the desired scenario on the evacuation simulation control panel.

When the fire dynamics simulation is conducted, FDS creates many different files. Here is a description of some of them.

The label XXXXXXXX in the file name indicates the ID of the scenario.

• XXXXXXXX.fds - is the FDS source file;

• XXXXXXXX.out - is the file, which contains statistics of the simulation process;

• XXXXXXXX.smv - is the data file for visualizing simulation results in Smokeview application;

• XXXXXXXX_01.s3d - are files containing information on the distribution of smoke and fire;

• XXXXXXXX_devc.csv - are files containing information on how danferous fire factors change in registering devices;

• XXXXXXXX.bf - files containing data about the heat flux change on obstacle surfaces;

• XXXXXXXX_0001.restart - contains information, which is necessary to resume simulation after it has been stopped;

• XXXXXXXX_xx.sf - are files containing information on the fields of dangerous fire factors;

• PROJECT NAME.fnx - is a copy of the project file, which includes only one scenario, results of which are stored in this folder. The project file extension can be different. For more information, see Logical Structure of Project Folder.

The application stores files with fire dynamics simulation results for a scenario until you run a new simulation in this scenario. Changing fire dynamics simulation parameters, editing the topology of the building or changing the fire component of the scenario does not modify or delete files with evacuation simulation results. If you make changes to the scenario and close the project without running a new simulation, when you open the project again the program displays the fire dynamics results from the previous simulation that do not reflect the changes made.

Viewing fire dynamics simulation results

There are several ways to view fire dynamics simulation results:

1. Using Fenix+ 3 application tools.
2. Using Smokeview application.

Using Fenix+ 3 application native tools, you can view simulation results as tables and graphs, as well as playback the fire dynamics.

To view simulation results in tables and graphs in fire risk calculation projects, navigate to the simulation results view tab and switch to the Fire tab.

In the graph below, the red line shows the maximum allowed (critical) value for the selected dangerous fire factor. The maximum allowed values for all dangerous fire factors are provided below:

• Temperature - 70°C;
• Visibility - 20 m
• Oxygen concentration $O_2$ – 0,226 kg/m³
• Carbon dioxide concentration $CO_2$ – 0,11 kg/m³
• Carbon monoxide concentration $CO$ – 1,16·10-3 kg/m³
• Hydrogen chloride concentration $HCl$ – 23·10-6 kg/m³

The graph can display how any dangerous fire factor changes in any control point. For example, the figure above displays how all dangerous fire factors change in the place where door is located.

To select a dangerous fire factor and a control point, click a corresponding cell. To select multiple cells, use the Shift and Ctrl keys.

To display all dangerous fire factors for one control point, press the LMB on the cell with the name of the desired control point.

If the registering device has several control points, you can view how a certain dangerous fire factor changes in all control points. For this, click on the cell that corresponds to the desired registering device and the desired dangerous fire factor.

If different dangerous fire factors are selected on the graph, then the value of each dangerous fire factor is reduced to the critical value (marked with the * symbol on the graph). As a result, the critical value for all dangerous fire factors on the graph equals to 1.

If Visibility is selected for several control points with different critical values, then all values are reduced to the critical value in the corresponding control point.

You can configure the application settings so that values of dangerous fire factors are always reduced to the critical value. For more information, see General Settings.

To view the simulation results as tables and graphs in a universal project when calculating fire safety distances, switch to the tab for simulation results.

On the Heat Flux tab, a table is displayed showing the calculation results: values of critical heat flux qcrit, threshold heat flux qthres, and incident heat flux qinc for all objects located within the boundaries of the calculation area. On the right side of the window, a graph showing the change in heat flux density is displayed.

When you select a value in the table, the dynamics of the change in heat flux density for the corresponding object are displayed.

Heat flux is controlled in windows and on objects made of combustible materials located in a building without a fire source.

In the table with calculation data, color indication is used. If the value of the incident heat flux (qinc) for any object exceeds the value of the threshold heat flux (qthres), the corresponding entry in the table is highlighted in red.

On the Structure Temperature, a table is displayed which shows the results of the calculation of the maximum temperature of structures for all objects located within the boundaries of the calculation area. On the right side of the window, a graph showing the change in the temperature of structures is displayed.

When you select a value in the table, a graph of changes in the surface temperature of the corresponding object is displayed.

To view graphs of changes in the controlled volume in detectors, switch to the Detector tab.

The red line on the graph shows the value of the measured parameter (%/m), the yellow line shows the time to reach the threshold value (s), and the green line shows the activation time of the detector.

To playback the fire development, click the button on the additional tools panel. As a result, the panel for playback of the simulation results opens.

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The visualization panel is used to display evacuation simulation results as well as fire dynamics simulation results. To display fire dynamics simulation results, select the Fire dynamics option and click .

As a result, the visualization of the selected dangerous fire factor for the selected registering device is displayed in the scene editor.

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Fenix+ 3 application allows you to display visualization of the following dangerous fire factors (DFF):

• Temperature;
• Visibility;
• Oxygen concentration $O_2$;
• Hydrogen chloride concentration $CO_2$;
• Carbon dioxide concentration $CO$;
• Carbon monoxide concentration $HCl$.

Since the default height at which DFFs are measured is 1.7 meters from the level of the floor, some objects on the scene (including people) may appear under the DFF field. Thus, it may be inconvinient to display visualization of evacuation and fire dynamics simulation results at the same time. You can change the level at which DFF fields are displayed. For this, change the value in the Display Level field. The Display Level parameter only determines the level at which the DFF fields are displayed, but not the level at which they are measured.

To display the fire dynamics simulation results in Smokeview application, click Show results in 3D on the visualization panel. As a result, a window opens displaying all the objects located in the calculation area.

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In Smokeview application, press the RMB and select SOOT DENSITY.

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To display how the flames on the burning objects, press the RMB anywhere in the application window and select HRRPUV

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To display the dynamics of the heat flux, right-click in the Smokeview application window and select INCIDENT HEAT FLUX from the opened menu.

Viewing the dynamics of the heat flux is only possible in a universal project.

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To view the DDF fields right-click in the Smokeview application window and select “Slice” from the menu that opens. After that, choose the required DFF and the desired plane.

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Viewing the vertical DFF fields is only possible in projects, where the Measuring device element is installed.

There are other options you can use when viewing simulation results in Smokeview. For more information follow the Smokeview user guide (Fire Dynamics Simulator (FDS) and Smokeview (SMV) manuals).