WFDS

class wfds.WFDS(x, y, z, xA, xO, res, n, fuels)

Bases: wfds.Mesh

This class configures a WFDS simulation. It gathers and calculates WFDS paramters and writes them to a WFDS input file.

WFDS() is a subclass of the Mesh() class and meshes are dealt with implicitly.

Parameters:

• x (integer) – scene size in the x dimension
• y (integer) – scene size in the y dimension
• z (integer) – scene size in the z dimension
• xA (integer) – x dimension of the Area Of Interest
• xO (integer) – x offset
• res (double) – simulation resolution
• n (integer) – number of WFDS meshes
• fuels (object) – fuels object (fuels.py, class: FVSfuels)

The following example assumes that a fuels object has been created using the fuels module.

Example:

>>> fds = wfds.WFDS(160, 90, 50, 64, 83, 1, 1, fuels)
>>> fds.create_mesh(stretch={"CC":[3, 33], "PC":[1, 31]})
>>> fds.create_ignition(30, 50, 24, 29, 13, 77)
>>> fds.set_hrrpua(1000)
>>> fds.set_wind_speed(9)
>>> fds.set_init_temp(30)
>>> fds.set_simulation_time(300)
>>> fds.set_run_name("standard_run")
>>> fds.save_input("C:/temp/standard_run.txt")

create_ignition(start_time, end_time, x_strt, x_end, y_strt, y_end)

Places an ignition strip at the specified location and generates fire at the specified Heat Release Rate Per Unit Area (HRRPUA) for the specified duration.

Parameters:

• start_time (integer) – start time of the igniter fire
• end_time (integer) – finish time of the igniter fire
• x_strt (float) – starting x position of the ignition strip
• x_end (float) – ending x position of the ignition strip
• y_strt (float) – starting y position of the ignition strip
• y_end (float) – ending y position of the ignition strip

Note

Ignition ramping is dealt with explicitly to avoid “explosions”

create_mesh(stretch=False)

Collates and adds mesh parameters to the params dictionary. Conditionally calls the stretch_mesh() method of the Mesh class depending on the state of the stretch argument. Calls the format_mesh() method of the Mesh class.

Parameters:stretch (False or dictionary of stretch parameters) – to stretch or not to stretch

Example dictionary of stretch parameters:

{“CC”:[3, 33], “PC”:[1, 31]}

Note

See Mesh.stretch_mesh() for setting the stretch arguments

save_input(file_name)

Creates and saves the WFDS input file using a template file. Include the desired directory in the string.

Parameters:file_name (string) – path to and name of WFDS input file (.txt NOT .fds)

set_hrrpua(hrr)

Set the heat release rate per unit area for the ignition strip

Parameters:hrr (integer) – heat release rate per unit area (kW/m^2)

set_init_temp(temp)

Set the initial temperature of the simulation

Parameters:temp (float) – temperature (celcius)

set_run_name(name)

Adds the run name to params dictionary

Params name:run name

set_simulation_time(sim_time)

Set the duration of the simulation

Parameters:sim_time (float) – duration of the simulation (s)

set_wind_speed(inflow_spd)

Set the inflow wind speed

Parameters:inflow_spd (float) – inflow wind speed (m/s)