[av147@snu.edu.in]

Hi All !

I am working on CFD analysis of PCMs, while doing the solidification/melting analysis of a cuboid block of pcm with one side wall and one top wall and others being adiabatic walls. I gave the top and side wall's BC as the following:

Heat transfer coefficient: 28 W/m2-K
Free stream temp: 288.15 K

and did hybrid initialisation and gave the patch temperature as : 317.15 K

Now i was getting Area weighted average Temperature as a text file, my question is the data shows a gradual decrease from time step 1 when the temp is 297.678 to time step 25200 when the temp is 294, shouldn't the temperature decrease happen from 317.15 K, why is it happening from 297.678 K ?

[Cryo1991]

try standard initialization

[av147@snu.edu.in]

Hi

Thanks for your reply, I tried standard initialisation, but got same results, i think i have figured out what the problem is, so i saved data files at each time step and found at time:

t=0, Temperature =317.15 K
t=1, Temperature = 297.73532 K
t =2, temperature =297.73385 K

So basically for t=0 to t=1, there is a very rapid decline in temperature and after that temperature sips slowly with time, any inputs or solutions to this ?

[Cryo1991]

well....decrease your time step then
1s is definitely too long