"Dynamically" Sync Front and Back Obst. Temp. in FDS

[Haukiy]

Hello,
I need to dynamically set the -FDS calculated- front surface temperature of an obstruction to "match" the back surface temperature during the simulation. The back surface temperature should not be predefined but calculated in real-time. I am looking for a solution that allows me to use the mean, maximum, or minimum front surface temperature from a statistical device.

One idea is to track the mean temperature of the front surface using:
&DEVC ID='Stat_Mean', QUANTITY='WALL TEMPERATURE', SPATIAL_STATISTIC='MEAN', XB=1.0,2.0,2.0,2.0,0.0,2.8 /
and use this value as input for TMP_BACK. However, I couldn’t get it to work. My approach was:

&SURF ID='Glas', TMP_BACK=20.0, RAMP_T_B='RAMP_T_B' /
&RAMP ID='RAMP_T_B', T=0, F=1.0, DEVC_ID='Stat_Mean' /

My FDS calculation failed. Is there a better workaround, or did I miss something in the User Guide?

Any insights or suggestions would be greatly appreciated!

[drjfloyd]

DEVC_ID controls the independent variable, i.e., the T in the RAMP. The output, F, is the dependent variable. See 18.6.2.