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drjfloyd merged 1 commit into from
Nov 30, 2025
Merged

FDS Verification: set 0 K ambient for rad cases that are assuming it … #15633

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2 changes: 1 addition & 1 deletion Manuals/FDS_Verification_Guide/FDS_Verification_Guide.tex
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Expand Up @@ -3307,7 +3307,7 @@ \section{Radiation Shield (\texorpdfstring{\ct{radiation_shield}}{radiation_shie
\section{Radiation from a gas-fired panel (\texorpdfstring{\ct{radiation_gas_panel}}{radiation_gas_panel}) }
\label{radiation_gas_panel}

A gas-fired panel is often used as a source of thermal radiation in laboratory experiments. Here, the heat flux from an $h=30.48$~cm square panel is computed at distances of 10~cm, 15~cm, 25~cm, 38~cm, 46~cm, 61~cm, and 76~cm along its perpendicular center axis, and along a perpendicular line that is displaced laterally 14~cm and vertically 14~cm from the center axis, as illustrated in Fig.~\ref{radiation_gas_panel_plot}. We compare the results computed by FDS to those calculated using configuration factors. The temperature and emissivity of the panel are set to 1250~K and 0.7, respectively, and the ambient temperature is 273~K.
A gas-fired panel is often used as a source of thermal radiation in laboratory experiments. Here, the heat flux from an $h=30.48$~cm square panel is computed at distances of 10~cm, 15~cm, 25~cm, 38~cm, 46~cm, 61~cm, and 76~cm along its perpendicular center axis, and along a perpendicular line that is displaced laterally 14~cm and vertically 14~cm from the center axis, as illustrated in Fig.~\ref{radiation_gas_panel_plot}. We compare the results computed by FDS to those calculated using configuration factors. The temperature and emissivity of the panel are set to 1250~K and 0.7, respectively, and the ambient temperature is 0~K.

The configuration factor, $\d F_{2 \rightarrow 1}$, describing the energy exchange between the radiant panel and a target with differential area $\d A_1$ located on a perpendicular line extending from the panel at the point $(\overline{x}, \overline{y})$ is computed from the following:
\begin{align}
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2 changes: 2 additions & 0 deletions Verification/Radiation/geom_rad.fds
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Expand Up @@ -10,6 +10,8 @@

&TIME T_END=2 /

&MISC TMPA=-273.14/

&SPEC ID='NITROGEN', BACKGROUND=.TRUE./

&RADI NUMBER_RADIATION_ANGLES=400 /
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2 changes: 2 additions & 0 deletions Verification/Radiation/geom_rad_2.fds
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Expand Up @@ -15,6 +15,8 @@

&TIME T_END=2 /

&MISC TMPA=-273.14/

&SPEC ID='NITROGEN', BACKGROUND=.TRUE./

&RADI NUMBER_RADIATION_ANGLES=400 /
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4 changes: 2 additions & 2 deletions Verification/Radiation/plate_view_factor_2D_100.fds
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Expand Up @@ -4,9 +4,9 @@ The RADIATIVE HEAT FLUX should be 105.34 kW/m2

&MESH IJK=20,1,10, XB=0,2,-.5,.5,0,1 /

&TIME T_END=.1 DT = 0.001 /
&TIME T_END=.1 DT = 0.001 /

&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0./
&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0.,TMPA=-273.14/

&RADI NUMBER_RADIATION_ANGLES = 100 /

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4 changes: 2 additions & 2 deletions Verification/Radiation/plate_view_factor_2D_30.fds
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Expand Up @@ -4,9 +4,9 @@ The RADIATIVE HEAT FLUX should be 105.34 kW/m2

&MESH IJK=20,1,10, XB=0,2,-.5,.5,0,1 /

&TIME T_END=.1 DT = 0.001 /
&TIME T_END=.1 DT = 0.001 /

&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0./
&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0.,TMPA=-273.14/

&RADI NUMBER_RADIATION_ANGLES = 30 /

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4 changes: 2 additions & 2 deletions Verification/Radiation/plate_view_factor_2D_60.fds
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Expand Up @@ -4,9 +4,9 @@ The RADIATIVE HEAT FLUX should be 105.34 kW/m2

&MESH IJK=20,1,10, XB=0,2,-.5,.5,0,1 /

&TIME T_END=.1 DT = 0.001 /
&TIME T_END=.1 DT = 0.001 /

&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0./
&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0.,TMPA=-273.14/

&RADI NUMBER_RADIATION_ANGLES = 60 /

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4 changes: 2 additions & 2 deletions Verification/Radiation/plate_view_factor_cart_100.fds
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Expand Up @@ -4,9 +4,9 @@ The RADIATIVE HEAT FLUX should be 81.8 kW/m2.

&MESH IJK=20,20,10, XB=0,2,0,2,0,1 /

&TIME T_END=.01 DT = 0.001 /
&TIME T_END=.01 DT = 0.001 /

&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0./
&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0.,TMPA=-273.14/



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4 changes: 2 additions & 2 deletions Verification/Radiation/plate_view_factor_cart_30.fds
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Expand Up @@ -4,9 +4,9 @@ The RADIATIVE HEAT FLUX should be 81.8 kW/m2.

&MESH IJK=20,20,10, XB=0,2,0,2,0,1 /

&TIME T_END=.01 DT = 0.001 /
&TIME T_END=.01 DT = 0.001 /

&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0./
&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0.,TMPA=-273.14/

&RADI NUMBER_RADIATION_ANGLES = 30 /

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4 changes: 2 additions & 2 deletions Verification/Radiation/plate_view_factor_cart_60.fds
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Expand Up @@ -4,9 +4,9 @@ The RADIATIVE HEAT FLUX should be 81.8 kW/m2.

&MESH IJK=20,20,10, XB=0,2,0,2,0,1 /

&TIME T_END=.01 DT = 0.001 /
&TIME T_END=.01 DT = 0.001 /

&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0./
&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0.,TMPA=-273.14/

&RADI NUMBER_RADIATION_ANGLES = 60 /

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4 changes: 2 additions & 2 deletions Verification/Radiation/plate_view_factor_cyl_100.fds
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Expand Up @@ -4,9 +4,9 @@ The RADIATIVE HEAT FLUX should be 74.1 kW/m2

&MESH IJK=10,1,10, XB=0.0,3.0,-.5,.5,0.0,3.0 CYLINDRICAL = .TRUE. /

&TIME T_END=.1 DT = 0.0001 /
&TIME T_END=.1 DT = 0.0001 /

&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0./
&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0.,TMPA=-273.14/



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4 changes: 2 additions & 2 deletions Verification/Radiation/plate_view_factor_cyl_30.fds
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Expand Up @@ -4,9 +4,9 @@ The RADIATIVE HEAT FLUX should be 74.1 kW/m2

&MESH IJK=10,1,10, XB=0.0,3.0,-.5,.5,0.0,3.0 CYLINDRICAL = .TRUE. /

&TIME T_END=.1 DT = 0.0001 /
&TIME T_END=.1 DT = 0.0001 /

&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0./
&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0.,TMPA=-273.14/



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4 changes: 2 additions & 2 deletions Verification/Radiation/plate_view_factor_cyl_60.fds
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Expand Up @@ -4,9 +4,9 @@ The RADIATIVE HEAT FLUX should be 74.1 kW/m2

&MESH IJK=10,1,10, XB=0.0,3.0,-.5,.5,0.0,3.0 CYLINDRICAL = .TRUE. /

&TIME T_END=.1 DT = 0.0001 /
&TIME T_END=.1 DT = 0.0001 /

&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0./
&MISC GVEC=0,0,0,Y_CO2_INFTY=0.,HUMIDITY=0.,TMPA=-273.14/



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10 changes: 5 additions & 5 deletions Verification/Radiation/plate_view_factor_ibm_100.fds
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Expand Up @@ -4,9 +4,9 @@ The RADIATIVE HEAT FLUX should be 81.8 kW/m2

&MESH IJK=100,100,100, XB=-1.0,2.0,-0.5,2.5,-0.5,2.5 /

&TIME T_END=.01 DT=0.001 /
&TIME T_END=.01 DT=0.001 /

&MISC GVEC=0,0,0, Y_CO2_INFTY=0., HUMIDITY=0. /
&MISC GVEC=0,0,0, Y_CO2_INFTY=0., HUMIDITY=0.,TMPA=-273.14 /

&RADI NUMBER_RADIATION_ANGLES=100 /

Expand All @@ -27,7 +27,7 @@ The RADIATIVE HEAT FLUX should be 81.8 kW/m2
VERTS= 0.0 , 0.0, 0.0
1.414214, 0.0, 1.414214
1.414214, 2.0, 1.414214
0.0 , 2.0, 0.0
0.0 , 2.0, 0.0
-0.07071 , 0.0, 0.07071
1.343503, 0.0, 1.484924
1.343503, 2.0, 1.484924
Expand All @@ -50,10 +50,10 @@ The RADIATIVE HEAT FLUX should be 81.8 kW/m2
0.636396, 0.0, 2.192031
0.636396, 2.0, 2.192031
-0.77782 , 2.0, 0.777817
-0.84853 , 0.0, 0.84853
-0.84853 , 0.0, 0.84853
0.565685, 0.0, 2.262742
0.565685, 2.0, 2.262742
-0.84853 , 2.0, 0.84853
-0.84853 , 2.0, 0.84853
FACES=1,2,6, 1
1,6,5, 1
2,3,7, 1
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10 changes: 5 additions & 5 deletions Verification/Radiation/plate_view_factor_ibm_30.fds
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Expand Up @@ -4,9 +4,9 @@ The RADIATIVE HEAT FLUX should be 81.8 kW/m2

&MESH IJK=100,100,100, XB=-1.0,2.0,-0.5,2.5,-0.5,2.5 /

&TIME T_END=.01 DT=0.001 /
&TIME T_END=.01 DT=0.001 /

&MISC GVEC=0,0,0, Y_CO2_INFTY=0., HUMIDITY=0. /
&MISC GVEC=0,0,0, Y_CO2_INFTY=0., HUMIDITY=0.,TMPA=-273.14 /

&RADI NUMBER_RADIATION_ANGLES=30 /

Expand All @@ -27,7 +27,7 @@ The RADIATIVE HEAT FLUX should be 81.8 kW/m2
VERTS= 0.0 , 0.0, 0.0
1.414214, 0.0, 1.414214
1.414214, 2.0, 1.414214
0.0 , 2.0, 0.0
0.0 , 2.0, 0.0
-0.07071 , 0.0, 0.07071
1.343503, 0.0, 1.484924
1.343503, 2.0, 1.484924
Expand All @@ -50,10 +50,10 @@ The RADIATIVE HEAT FLUX should be 81.8 kW/m2
0.636396, 0.0, 2.192031
0.636396, 2.0, 2.192031
-0.77782 , 2.0, 0.777817
-0.84853 , 0.0, 0.84853
-0.84853 , 0.0, 0.84853
0.565685, 0.0, 2.262742
0.565685, 2.0, 2.262742
-0.84853 , 2.0, 0.84853
-0.84853 , 2.0, 0.84853
FACES=1,2,6, 1
1,6,5, 1
2,3,7, 1
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10 changes: 5 additions & 5 deletions Verification/Radiation/plate_view_factor_ibm_60.fds
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Expand Up @@ -4,9 +4,9 @@ The RADIATIVE HEAT FLUX should be 81.8 kW/m2

&MESH IJK=100,100,100, XB=-1.0,2.0,-0.5,2.5,-0.5,2.5 /

&TIME T_END=.01 DT=0.001 /
&TIME T_END=.01 DT=0.001 /

&MISC GVEC=0,0,0, Y_CO2_INFTY=0., HUMIDITY=0. /
&MISC GVEC=0,0,0, Y_CO2_INFTY=0., HUMIDITY=0.,TMPA=-273.14 /

&RADI NUMBER_RADIATION_ANGLES=60 /

Expand All @@ -27,7 +27,7 @@ The RADIATIVE HEAT FLUX should be 81.8 kW/m2
VERTS= 0.0 , 0.0, 0.0
1.414214, 0.0, 1.414214
1.414214, 2.0, 1.414214
0.0 , 2.0, 0.0
0.0 , 2.0, 0.0
-0.07071 , 0.0, 0.07071
1.343503, 0.0, 1.484924
1.343503, 2.0, 1.484924
Expand All @@ -50,10 +50,10 @@ The RADIATIVE HEAT FLUX should be 81.8 kW/m2
0.636396, 0.0, 2.192031
0.636396, 2.0, 2.192031
-0.77782 , 2.0, 0.777817
-0.84853 , 0.0, 0.84853
-0.84853 , 0.0, 0.84853
0.565685, 0.0, 2.262742
0.565685, 2.0, 2.262742
-0.84853 , 2.0, 0.84853
-0.84853 , 2.0, 0.84853
FACES=1,2,6, 1
1,6,5, 1
2,3,7, 1
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2 changes: 1 addition & 1 deletion Verification/Radiation/radiation_gas_panel.fds
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Expand Up @@ -2,7 +2,7 @@

&TIME T_END=1.5 /

&MISC TMPA=0 /
&MISC TMPA=-273.14 /

&MESH IJK=90,30,30, XB=0.0,0.3,-0.1524, 0.1524,-0.1524, 0.1524, MULT_ID='mesh' /
&MULT ID='mesh', DX=0.3, I_UPPER=2 /
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