Why wind tunnel experiment and CFD domain are different?

misospider · January 10, 2017, 03:41

Hi, fellows.
I have read many papers comparing wind tunnel experiment data vs CFD result.
But I could not find enough explanation for the domain difference between experiment and CFD.

Let's say an airfoil wind tunnel test has been conducted in certain chamber (2m*2m*20m, W*H*L), in CFD we usually do not make domain same as wind tunnel, rather we will make much larger domain(C-grid/O-grid) to set BC as freestream values.

How can I defend my result even though domain size is different?

I have tested in CFD both wind tunnel size domain and larger domain, larger domain result provides me much closer to wind tunnel data. For your information, my case is 2D.

Can anyone give me some explanation for this matter?

Thanks in advance.

KateEisenhower · February 6, 2017, 04:31

Hi,

keep in mind that published data from wind tunnels is normally corrected. Search for "wind tunnel wall corrections" if you really want to dive into this topic.

Best regards,

Kate

January 10, 2017, 03:41	Why wind tunnel experiment and CFD domain are different?	#1
misospider New Member WJ Join Date: Feb 2016 Location: MyHome Posts: 11 Rep Power: 10	Hi, fellows. I have read many papers comparing wind tunnel experiment data vs CFD result. But I could not find enough explanation for the domain difference between experiment and CFD. Let's say an airfoil wind tunnel test has been conducted in certain chamber (2m2m20m, WHL), in CFD we usually do not make domain same as wind tunnel, rather we will make much larger domain(C-grid/O-grid) to set BC as freestream values. How can I defend my result even though domain size is different? I have tested in CFD both wind tunnel size domain and larger domain, larger domain result provides me much closer to wind tunnel data. For your information, my case is 2D. Can anyone give me some explanation for this matter? Thanks in advance.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Looking for help with a CFD project, mimicking a wind tunnel experiment	thewalrus	CFD Freelancers	1	November 3, 2016 13:25
need wind turbine data for cfd validation	Reggio	Main CFD Forum	0	September 9, 2012 11:30
validation of CFD and windtunnel experiment	M.Arun prasad	FLUENT	4	March 13, 2008 02:12
Wind Tunnel Experiment Validation	zi	FLUENT	1	August 5, 2005 18:19
CFD versus Wind Tunnel Test	wuttichai	Main CFD Forum	3	November 12, 2003 00:07

February 6, 2017, 04:31		#2
KateEisenhower Senior Member Join Date: Mar 2015 Posts: 250 Rep Power: 12	Hi, keep in mind that published data from wind tunnels is normally corrected. Search for "wind tunnel wall corrections" if you really want to dive into this topic. Best regards, Kate