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Cp Values for a solar chimney   Message List  
Reply | Forward Message #853 of 858 |
RE: [comis] Cp Values for a solar chimney

David,
in the past TNO has done wind tunnel research on that topic.
It was the basis for Dutch regulations for exhaust outlet and chimney positions above the roof.
I do have some documentation, but this is only available in Dutch. However, the figures (see example) may give you a good impression.
The question is in what matter these data are applicable to your configuration of a clerestory building.
Though our Cp-Generator has an option to put Cp-spots some distance above the roof, this does not yet have an effect. 
The data mentioned above are not yet implied in the program.
 
regards,
 
Bas Knoll
TNO Building research, NL
 


From: comis@yahoogroups.com [mailto:comis@yahoogroups.com] On Behalf Of David Bradley
Sent: 20 January, 2009 18:42
To: comis@yahoogroups.com
Subject: [comis] Cp Values for a solar chimney

Colleagues,
I am attempting to model a clerestory building. On the lower roof
there are a number of solar chimneys that rise above the roof but not so
high as the peak of the clerestory. I am struggling a bit with how to
estimate the wind pressure coefficients (Cp values) of the chimney tops
so that I can calculate the wind-driven part of their air flow. I have
used the TNO CpGenerator tool to obtain Cp values for the roof surfaces
themselves. Does anyone have any experience or suggestions as to how Cp
might vary for positions above the lower roof surface? Any suggestions
would be appreciated.
Kind regards,
David

PS if my explanation of the building configuration is unclear, please
let me know and I would be happy to email a sketch of what I am trying
to model.

--
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Thermal Energy System Specialists (TESS), LLC
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Partner Madison, WI 53703
USA
P: +1.608.274.2577
F: +1.608.278.1475
E-mail: bradley@tess-inc.com
Web Pages: http://www.tess-inc.com and http://www.trnsys.com

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Wed Jan 21, 2009 1:01 pm

basknoll
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Message #853 of 858 |
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Colleagues, I am attempting to model a clerestory building. On the lower roof there are a number of solar chimneys that rise above the roof but not so high as...
David Bradley
tesstrnsys
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Jan 20, 2009
5:42 pm

Dear David The pressure coefficient at the end of a chimney is a combination the Cp value on the considered position above the roof and on the Cp value of the...
Andreas Weber
andreas_webe...
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Jan 21, 2009
12:57 pm

David, in the past TNO has done wind tunnel research on that topic. It was the basis for Dutch regulations for exhaust outlet and chimney positions above the...
Knoll, B. (Bas)
basknoll
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Jan 21, 2009
1:01 pm

Try this: Experimental and Theoretical Studies of a Solar Chimney with Uniform Wall Heat Flux by Jónas Halldórsson and Christian Byrjalsen Aalborg University...
Eric Hernández De...
mtbmexico
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Jan 22, 2009
4:33 am

Dear David, I can provide some reference values for you. However, it may not be the best case to use any "reference" data due to the strong dependence between...
Daniel Cóstola
daniel_costola
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Jan 23, 2009
12:38 pm
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