Nusselt number in tube

February 28, 2006, 08:29

Hi all

I want to calculate Nusselt number in a tube.... I use the heat transfer coefficient provided by Star

Nu= hcoeff * D/K

but I didn't get the right solution.

Any hints.

Thanks alot

March 1, 2006, 02:48

hcoef seems ok, did you check your TBulk temperature?

March 1, 2006, 06:42

Thanks alot.

I have checked that. I have used T_bulk=Sum(T*u)/Sum(u), the sum goes all over the fluid cells. but It didn't give the right answer in comparison with the analytic solution.

Shall I multiply the h_coeff with the circumfincial area (2 Pi D)? or else.

Ahmad

moh1367 · February 14, 2010, 04:50

Hi guys!

My case is very simple , its laminar flow in a pipe with constant wall temperature. I take the length as long as the flow can reach to fully thermally and Hydrodunamically developed. When I get the Nusselt Number from the xyplot/Surface Nusselt Number it can seemed that the Nu begins from a large number(as predicted by theory) and go toward zero at the end of pipe (the theoric value is 3.66). Can anybody help me?
I can send my case to you for more information.

Thanks alot
.

February 28, 2006, 08:29	Nusselt number in tube	#1
A. Al-Zoubi Guest Posts: n/a	Hi all I want to calculate Nusselt number in a tube.... I use the heat transfer coefficient provided by Star Nu= hcoeff * D/K but I didn't get the right solution. Any hints. Thanks alot

March 1, 2006, 02:48	Re: Nusselt number in tube	#2
PETE Guest Posts: n/a	hcoef seems ok, did you check your TBulk temperature?

March 1, 2006, 06:42	Re: Nusselt number in tube	#3
A. Al-Zoubi Guest Posts: n/a	Thanks alot. I have checked that. I have used T_bulk=Sum(T*u)/Sum(u), the sum goes all over the fluid cells. but It didn't give the right answer in comparison with the analytic solution. Shall I multiply the h_coeff with the circumfincial area (2 Pi D)? or else. Ahmad

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February 14, 2010, 04:50		#4
moh1367 Member Mohammad Zakerzadeh Join Date: Dec 2009 Location: Aachen, Germany Posts: 40 Rep Power: 17	Hi guys! My case is very simple , its laminar flow in a pipe with constant wall temperature. I take the length as long as the flow can reach to fully thermally and Hydrodunamically developed. When I get the Nusselt Number from the xyplot/Surface Nusselt Number it can seemed that the Nu begins from a large number(as predicted by theory) and go toward zero at the end of pipe (the theoric value is 3.66). Can anybody help me? I can send my case to you for more information. Thanks alot .