natural convection ventilation

braennstroem · February 20, 2011, 14:50

Hi,

I am just trying to setup a small test case in 1.7.x for a generic HVAC case with two dummy cylinders placed in the room as a heat source with a heat flux boundary condition... I attached the case with the snappy mesh.
The meshing and running works fine... unfortunately there is no 'plume' development above the cylinder. The heat flux/power is set to 50W for the cylinder1 and it should give for this setup a velocity of around up to 0,2m/s at 40cm above the cylinder... I get something with 4e-5 m/s (just after 350 iterations, but this is still strange for me) !?
It is probably a quite stupid mistake, but I can't find it and would be happy, if one of you have a hint, what I am doing wrong with the setup!? I actually tried to upload the stl's as well, but they were a bit too large, so if someone needs them I would send it by mail.

Best Regards!
Fabian

Btw... the above counts for a relaxation factor of 1.0 for rho and not like in the fvSolution of 0.01 and the z-direction goes a long with the height of the room.

braennstroem · February 21, 2011, 02:37

sorry bothering you, I was just not waiting long enough ;-)
After around 1500 iterations I could see that it goes in the right direction...

lmblanes · March 28, 2011, 08:59

Hello Fabian

Which solver do you use to run the Code?

Thanks

braennstroem · March 29, 2011, 13:03

buoyantSimpleFoam

March 28, 2011, 08:59	Luis	#3
lmblanes New Member Luis Blanes Join Date: Mar 2011 Location: Cardiff. UK. Posts: 12 Rep Power: 15	Hello Fabian Which solver do you use to run the Code? Thanks

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Natural Convection with heat generation	krishnachandranr	Main CFD Forum	0	July 28, 2009 04:22
Coupled vs Seg - Natural vs. Forced Convection	Alex	Siemens	5	December 12, 2007 04:58
natural convection at high Rayleigh	mauricio	FLUENT	2	February 23, 2005 19:43
Approximate Mixing due to Natural Convection	Greg Perkins	Main CFD Forum	0	February 12, 2003 18:43
natural convection in a sealed enclosure	James	Main CFD Forum	4	April 2, 2001 15:48

February 21, 2011, 02:37		#2
braennstroem Senior Member Fabian Braennstroem Join Date: Mar 2009 Posts: 407 Rep Power: 19	sorry bothering you, I was just not waiting long enough ;-) After around 1500 iterations I could see that it goes in the right direction...

March 29, 2011, 13:03		#4
braennstroem Senior Member Fabian Braennstroem Join Date: Mar 2009 Posts: 407 Rep Power: 19	buoyantSimpleFoam