Fire event based on an FDS file

The Fire Dynamics Simulator (FDS) program can simulate a fire event and save the results in an *.fds file. In Vissim, you can select the *.fds file, load the data into Vissim and thus add and display the fire event as network object in the network editor.

You define the location of the fire event in the Vissim network when adding the fire event to the network editor (Defining fire events).

The extent of the fire event is based on the coordinates of grid cells defined in the *.fds file. This data is also imported in Vissim and is thus available as FDS mesh. Fire events do not support *.fds files with grids whose cells have different edge lengths. The *.fds file may contain floating point numbers in scientific notation (for example 4.2E-1 instead of 0.42), leading zero does not have to be specified (for example -.42 instead of -0.42).

FDS meshes and their attributes can be displayed in the FDS Meshes list and as relation for the Fire Event network object (Attributes of FDS meshes), (Fire event attributes).

As a result of the FDS simulation covering the entire FDS mesh, Plot3D Quantities can be stored in a Plot3D file *.q. Plot3D Quantities include attribute values for temperature, the direction of the heat expansion, and the speed at which gas components expand, for example. You can display the attributes of the Plot3D Quantities of a fire event as its relation (Fire event attributes). The Plot3D results can be visualized during the 3D simulation as an approximation of the actual impression of smoke (Graphic parameters for visualizing fire events).

Note: FDS results with file name extension .q can be read in directly by Viswalk up to FDS version 6.7.8. With version 6.7.9 the filenames of .q files have been re-structured and cannot be found by Viswalk and cannot be read without modification. To change this, replace the "p" in the third to last position before the file name extension ".q" in the file name by an underscore. Example: Before change: heptane_1_m_1_6p60.q After change: heptane_1_m_1_6_60.q

Attributes in the Pedestrians in network list indicate the current status of a pedestrian in the simulation with respect to the effects of fire events (Showing pedestrians in the network in a list).

The Plot3D files are embedded in the FDS simulation with the attributes FDS simulation time and simulation time. These can be displayed in the Plot3D Files Time Step list as relation for the FDS Mesh network object (Attributes of FDS meshes).

Data of irregular meshes can be stored in a *.xyz file or in the *.fds file and are taken into account when importing the *.fds file to Vissim.

The Fire Event network object is also displayed in 2D mode during the simulation run.

Note: When you import an *.fds file, Viswalk will not support the name list group &mult and its functions. Viswalk further ignores “meshes” defined this way in FDS.