Temperature profiles

mare910 · June 24, 2013, 15:55

hey guys.

I need some help. i have some problems with simulating 2 flat plate solar air heaters in a row. When i get results of first one, i write velocity and temperature profile of the air flow at outflow (and others temperature profiles at the end of panel (temperature of glass, insulation,..) and use this at inlet boundary condition in the next one. But when i look the results of the second panel are not ok. Temperature of air is looking fine ( rise with distance), but the temperature on others solid material at beginning is dropping from inlet parameters (prescribed temperatures) and after awhile it begin to rise again (this does not make sense).
When I'm doing wrong, can someone give me any advise?

Thanks and best regards

mare910 · July 2, 2013, 17:24

[QUOTE=mare910;435671]hey guys.

I need some help. i have some problems with simulating 2 flat plate solar air heaters in a row. When i get results of first one, i write velocity and temperature profile of the air flow at outflow (and others temperature profiles at the end of panel (temperature of glass, insulation,..) and use this at inlet boundary condition in the next one. But when i look the results of the second panel are not ok. Temperature of air is looking fine ( rise with distance), but the temperature on others solid material at beginning is dropping from inlet parameters (prescribed temperatures) and after awhile it begin to rise again (this does not make sense).
When I'm doing wrong, can someone give me any advise?

Thanks and best regards
Capture2.PNG

Capture4.PNG

kartrmswy · July 3, 2013, 01:22

Hi mare910,

A question: are you using a shell conduction boundary condition for the plates or constant heat flux? Also, have you given a thickness the walls?

Also, try looking at a temperature plot along the direction of heating to get a better idea - contours are sometimes deceptive

mare910 · July 3, 2013, 17:00

thanks for your replay.
I define constant temperature and for wall tickness i prescribed length of modul.

Quote:

Originally Posted by kartrmswy

Hi mare910,

A question: are you using a shell conduction boundary condition for the plates or constant heat flux? Also, have you given a thickness the walls?

Also, try looking at a temperature plot along the direction of heating to get a better idea - contours are sometimes deceptive

June 24, 2013, 15:55	Temperature profiles	#1
mare910 New Member Join Date: Mar 2012 Posts: 5 Rep Power: 14	hey guys. I need some help. i have some problems with simulating 2 flat plate solar air heaters in a row. When i get results of first one, i write velocity and temperature profile of the air flow at outflow (and others temperature profiles at the end of panel (temperature of glass, insulation,..) and use this at inlet boundary condition in the next one. But when i look the results of the second panel are not ok. Temperature of air is looking fine ( rise with distance), but the temperature on others solid material at beginning is dropping from inlet parameters (prescribed temperatures) and after awhile it begin to rise again (this does not make sense). When I'm doing wrong, can someone give me any advise? Thanks and best regards

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
whats the cause of error?	immortality	OpenFOAM Running, Solving & CFD	13	March 24, 2021 07:15
Calculation of the Governing Equations	Mihail	CFX	7	September 7, 2014 06:27
is internalField(U) equivalent to zeroGradient?	immortality	OpenFOAM Running, Solving & CFD	7	March 29, 2013 01:27
Fluent Temperature Profiles	jcd84	FLUENT	0	January 24, 2011 13:34
Time-Varying Temperature Profiles	shepardsp	ANSYS	3	October 17, 2010 14:36

July 2, 2013, 17:24		#2
mare910 New Member Join Date: Mar 2012 Posts: 5 Rep Power: 14	[QUOTE=mare910;435671]hey guys. I need some help. i have some problems with simulating 2 flat plate solar air heaters in a row. When i get results of first one, i write velocity and temperature profile of the air flow at outflow (and others temperature profiles at the end of panel (temperature of glass, insulation,..) and use this at inlet boundary condition in the next one. But when i look the results of the second panel are not ok. Temperature of air is looking fine ( rise with distance), but the temperature on others solid material at beginning is dropping from inlet parameters (prescribed temperatures) and after awhile it begin to rise again (this does not make sense). When I'm doing wrong, can someone give me any advise? Thanks and best regards Capture2.PNG Capture4.PNG

July 3, 2013, 01:22		#3
kartrmswy New Member Karthik Ramaswamy Join Date: Apr 2013 Posts: 7 Blog Entries: 1 Rep Power: 13	Hi mare910, A question: are you using a shell conduction boundary condition for the plates or constant heat flux? Also, have you given a thickness the walls? Also, try looking at a temperature plot along the direction of heating to get a better idea - contours are sometimes deceptive