Temperature lower than possible in closed domain

Czarulla · January 14, 2015, 07:59

I am working on transient model of natural convection with heat source inside the closed, cylindrical domain and one BC at the wall of cylinder. The BC is contant temperature of 323 K. Initial temperature of air inside this cylinder is equal to 350 K. After a certain time of simulation the temperature inside the lower part of cylinder fall down under 323 even to 293 K. Air is treated as an ideal gas. I have to mention that I also used S2S radiation model.

How is it possible for a closed domain to acquire from calculations a temperature, which lower than BC? Radiation heat transfer is also occuring from higher to lower temp? Could anyone explain it to me?

Best regards,
Czarulla

Czarulla · January 15, 2015, 06:01

I checked that without using S2S radiation model temperature is reasonable.

Could anyone give me some tips how to appropriately set the S2S radiation model? I cannot set the free stream temperature as this is not the case.

January 14, 2015, 07:59	Temperature lower than possible in closed domain	#1
Czarulla New Member Cezary Join Date: Jul 2014 Posts: 5 Rep Power: 12	I am working on transient model of natural convection with heat source inside the closed, cylindrical domain and one BC at the wall of cylinder. The BC is contant temperature of 323 K. Initial temperature of air inside this cylinder is equal to 350 K. After a certain time of simulation the temperature inside the lower part of cylinder fall down under 323 even to 293 K. Air is treated as an ideal gas. I have to mention that I also used S2S radiation model. How is it possible for a closed domain to acquire from calculations a temperature, which lower than BC? Radiation heat transfer is also occuring from higher to lower temp? Could anyone explain it to me? Best regards, Czarulla

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Setting Initial Temperature Of a Domain	mjkey	FLUENT	1	October 17, 2014 09:53
injection problem	Mark New	FLUENT	0	August 4, 2013 02:30
Help: floating pressure, multiphase, closed domain	memahfud	FLUENT	1	September 24, 2009 04:38
air bubble is disappear increasing time using vof	xujjun	CFX	9	June 9, 2009 08:59
No results for solid domain	Gary Holland	CFX	10	March 13, 2009 04:30

January 15, 2015, 06:01		#2
Czarulla New Member Cezary Join Date: Jul 2014 Posts: 5 Rep Power: 12	I checked that without using S2S radiation model temperature is reasonable. Could anyone give me some tips how to appropriately set the S2S radiation model? I cannot set the free stream temperature as this is not the case.