In the transient heat transfer PDE:
d2T/dx2=1/a*dT/dt , a=k/p*Cp
k= heat conduction, p=density, Cp= heat capacity
For example: if k=1, p=1 and Cp=1, the heat diffusivity a=1. I solve the PDE by Finite Element method I obtain a graph for T versus time (t).
But, when I multiply all the parameters by 2 (i.e. k=2, p=2, Cp=2), even though the parameter a=1, the profile is not the same!
Or if k=6, p=3, Cp=2, again the heat diffusivity parameter equals 1, but the temperature profile is different in comparison with the two aforementioned graphs.
This happens when I use the finite element method, but not for the Finite difference method. Is there any explanation for this issue?
By the way I am using FEHT software.
Thanks in advance
I should write an erratum to the following:
"But, when I multiply all the parameters by 2 (i.e. k=2, p=2, Cp=2), even though the parameter a=1, the profile is not the same!"
Here the parameter k=4 to have a=1.
Hi my professor
In this state, it's not possible, if the "a" is constant. But the a be function of time or temperature, it's possible that the your graph has difference shape. This is my opinion.
Hi my professor
In this state, it's not possible, if the "a" is constant. But the a be function of time or temperature, it's possible that the your graph has difference shape. This is my opinion.
Hi my professor
In this state, it's not possible, if the "a" is constant. But the a be function of time or temperature, it's possible that the your graph has difference shape. This is my opinion.
Dear colleagues,
My opinion is that if "a=const." it is not possible that in the same time k(x).
The observed difference between the results could be due to initial or boundary conditions if these are depending from "k" or "rho* Cp" separately and not direct from "a".
Best regards
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