DeltaDualCore™ Panel Awning Systems 
 
Revision 1-12 
41 
 
A 
= aggregate cross-sectional area of steel rod along the heat path (m2)  
 
c 
= specific heat (J/kgK) 
 
k 
= conductivity (W/mK) 
 
T 
= temperature (°C) 
 
t 
= time (s) 
 
x 
= distance (m) 
 
 
= density (kg/m3) 
h 
= convective heat transfer coefficient (W/m2/K) 
Ɛ  
= emissivity value 
σ 
= Stefan-Boltzmann (5.67 x 10-8 W/m2/K4) 
prefix: 
 
= small increment 
subscripts: 
 
 
s  
= metal (steel) 
 
O  
= node at which temperature is being determined 
 
n-1  
= previous time step of node O 
 
n+1  
= next time step of node O 
 
 
Using a spreadsheet, the temperature distribution through the steel rod was solved. The results are given 
in Figure 5-2. The thermal properties adopted are given in Table 5-1. More detailed explanation for explicit 
finite difference analysis of heat transfer can be found in Cengel et al (2011). 
 
Table 5-1.  Material thermal properties (Drysdale 1999) 
 
Copper 
Conductivity, k (W/mK) 
45.8 
Specific heat at constant pressure, c (J/kgK) 
460 
Density  (kg/m3) 
7850 
Emissivity 
0.7 
 
A.2  Results & Conclusion 
The temperature distribution through the steel rod after 60 minutes of exposure to standard fire is given in 
Figure 5-2. 
The results indicate that conductive heat attenuates quickly along the length of the steel rod and has no 
significant impact on the steel temperatures at a distance over 900 mm from the site boundary. 
Thus, conduction is not considered to present a dominant mechanism for heat transfer to the combustible 
component of the DeltaDualCore™ roof system. 
 
 

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