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Nusselt Number problem

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Old   February 28, 2012, 14:33
Default Nusselt Number problem
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Goutam Saha
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(buoyantBousseinsqSimpleFoam)

I want to calculate local and average Nusselt number for a square cavity when
T_left=303 K, T_right= 283 K, T_ref= 293 K, Detta T = 20, u=v=0 for all wall and uper and lower wall are adiabetic.

local Nu = -0.05 * Grad(T) at the wall

average Nu = Integration [local Nu, {y, 0, 1}]

How I will calculate this, please help me?

I am considering the benchmark problem, paper name:

Natural convection flow in a square cavity revisited: laminar and turbulent models with wall functions, International journal for numerical methods in fluids, vol. 18, pp. 695-719, 1994.
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Old   March 3, 2012, 09:34
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I have calculated the local one.
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Old   July 3, 2012, 09:10
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Primoz Ternik
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For obtaining the "average" Nusselt number use the numerical integration (Simpson's 1/3 method)!

What version of Open Foam have you used for your calculation?

Best,
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Old   July 5, 2012, 12:10
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Quote:
Originally Posted by ternik View Post
For obtaining the "average" Nusselt number use the numerical integration (Simpson's 1/3 method)!

What version of Open Foam have you used for your calculation?

Best,
Primoz
I have calculated both the local and average Nu. I am using OF 2.1.0.
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Old   July 5, 2012, 15:21
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Quote:
Originally Posted by Goutam View Post
I have calculated both the local and average Nu. I am using OF 2.1.0.
Nice! I hope your results are in agreement with the benchmark!

By the way, what Ra and Pr have you studied (modelled)? Because I have quite some problems with the Rayleigh-Benard convection (laminar natural convection in a square cavity heated from bellow) for Pr=10 and Ra=1e05; I am using buoyantBoussinesqSimpleFoam (Open Foam 2.1.1) and results are "not good" (maybe you can check my post buoyantBoussinesqSimpleFoam )

Is there a chance that you send me your case files?

Best,
primoz
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Old   July 12, 2012, 05:14
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Quote:
Originally Posted by Goutam View Post
I have calculated both the local and average Nu. I am using OF 2.1.0.
Dear Goutam,

I would realy appreciate if you could send me your natural convection case (i.e. files)!

I still have some problems with the Rayleigh-Benard convection (laminar natural convection in a square cavity heated from bellow) for Pr=10 and Ra=1e05; I am using buoyantBoussinesqSimpleFoam (Open Foam 2.1.1) and results are "not good".

Best,
Primoz
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