Skip to content

FDS Source: Set MAXIMUM_SCALING_HEAT_FLUX #14999

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
drjfloyd merged 2 commits into from
Aug 23, 2025
Merged

FDS Source: Set MAXIMUM_SCALING_HEAT_FLUX #14999

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
c62ba62
FDS Source: Set MAXIMUM_SCALING_FLUX to 300 kW/m2
drjfloyd Aug 21, 2025
144060c
FDS Source: Set MAXIMUM_SCALING_HEAT_FLUX
drjfloyd Aug 21, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 2 additions & 2 deletions Manuals/FDS_User_Guide/FDS_User_Guide.tex
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2837,7 +2837,7 @@ \subsection{Scaling Pyrolysis (SPyro) Model: Scaled Burning Rate from Cone Data}
There are other optional parameters which can be used to adjust the model behavior, which are described below.

\begin{itemize}
\item \ct{MAXIMUM_SCALING_HEAT_FLUX} By default the model does not set an upper limit on the predicted heat flux used to scale the test data (Default 100,000 \unit{kW/m^2}).
\item \ct{MAXIMUM_SCALING_HEAT_FLUX} The upper limit on the predicted heat flux used to scale the test data (Default 1500 \unit{kW/m^2}).
\item \ct{MINIMUM_SCALING_HEAT_FLUX} By default the model does not set a lower limit on the predicted heat flux used to scale the test data. Setting a lower bound to the flux used for scaling may help the model predictions in some cases such as weakly burning sources on coarse grids which may have poorly resolved heat feedback (Default 0 \unit{kW/m^2}).
\item \ct{REFERENCE_HEAT_FLUX_TIME_INTERVAL} The instantaneous heat feedback in FDS can vary greatly from time step to time step. In an actual fire the burning rate is tied to the sample temperature, and thermal inertia means the burning rate changes more slowly than then instantaneous flux. This natural smoothing can be approximated by setting a smoothing window using \ct{REFERENCE_HEAT_FLUX_TIME_INTERVAL} in s (Default 1~s).
\end{itemize}
Expand Down Expand Up @@ -13620,7 +13620,7 @@ \section{\texorpdfstring{{\tt SURF}}{SURF} (Surface Properties)}
\ct{MASS_TRANSFER_COEFFICIENT} & Real & Section~\ref{info:liquid_fuels} & m/s & \\ \hline
\ct{MATL_ID(:,:)} & Char.~Array & Section~\ref{info:solid_pyrolysis} & & \\ \hline
\ct{MATL_MASS_FRACTION(:,:)} & Real Array & Section~\ref{info:solid_pyrolysis} & & \\ \hline
\ct{MAXIMUM_SCALING_HEAT_FLUX} & Real & Section~\ref{info:scaled_burning} & \si{kW/m^2} & \\ \hline
\ct{MAXIMUM_SCALING_HEAT_FLUX} & Real & Section~\ref{info:scaled_burning} & \si{kW/m^2} & 1500 \\ \hline
\ct{MCC_CONVERSION_FACTOR} & Real & Section~\ref{info:TGA_DSC_MCC} & & 1 \\ \hline
\ct{MINIMUM_BURNOUT_TIME} & Real & Section~\ref{veg_burnout_time} & s & 1000000 \\ \hline
\ct{MINIMUM_LAYER_THICKNESS} & Real & Section~\ref{info:solid_phase_stability} & m & 1.E-4 \\ \hline
Expand Down
2 changes: 1 addition & 1 deletion Source/read.f90
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -9015,7 +9015,7 @@ SUBROUTINE SET_SURF_DEFAULTS
MATL_MASS_FRACTION = 0._EB
MATL_MASS_FRACTION(:,1) = 1._EB
MINIMUM_SCALING_HEAT_FLUX = 0._EB
MAXIMUM_SCALING_HEAT_FLUX = 1.E9_EB
MAXIMUM_SCALING_HEAT_FLUX = 1500._EB
MINIMUM_BURNOUT_TIME = 1.E6_EB
MINIMUM_LAYER_MASS_FRACTION = 1.E-12_EB
MINIMUM_LAYER_THICKNESS = -1.E-6_EB ! The absolute value is the default, m
Expand Down
Loading