Question

We are testing a 2 cm thick insulating material. The density, thermal conductivity, and heat capacity of the insulating material are 255 kg/m°, 0.07 W/m. K, and 1300 J/kg. K, respectively. If our experiments take 10 min, is it possible to assume pseudo-steady-state behavior? For the pseudo-steady-state approximation to be valid, we must satisfy, atch > 1 L2 ch

Answer 1

given 2cm thickness of insulating material (heh ) = = 0.02m cm - 10-2 material (k)=0.07 W/km thermal conductivity of of density material (8)= 255 kg/m3 heat capacity of material (Cp) = 1300 J kg.k

We know thermal diffusivity - 0.07 255 x 1300 T singin I kg vagy mer 又 = m/s = 9.1116 x107 mily's 0.07 331500 given time of experiment &ton) = 10 min = 10 x 60 sec = 6oosec Imin 60 sec given, for to be valid, Pypu preudo - steady state atch ا<< lan
​​​​​​
atch Lin 2.1116x107 x 600 хя 6.02)2 thes 0.0001266968 (0.02)2 = 0.31674 xitch 177 we cannot assume psuedo Steady 2 Lin State behaviour.
alll the symbols carry usual meaning.thank you