Surface Nusselt Number tooooo high

kamran651 · November 29, 2011, 02:46

Hi brothers,
I have designed a 1m length rectangular 2D cylinder-type model with. the inlet is 0.125 m on the top, and the flow is in the -Y direction and moving along the x direction after impinging on the wall below..my question is i want to study the heat transfer and Surface Nusselt Number on the impinging wall, i am using 2ddp realizable k-e model and set all the values correctly..my concern is
>>> the Surface nusselt number on the impinging wall is coming out to be in the range of 5000, whereas as previous studies or comparison, it should come out to be between 120-150.
anyone has any idea.where i am going wrong.???
Help highly appreciated

bets Regards.

CFDaniel · January 9, 2012, 02:14

Hi,

As far as I know, try to change the reference values given in the reference values menu. It doesnt need to start the simulation again. Those values only work for postprocessing.

You may take:

D as your hydraulic diameter
T as your reference pressure

Check it

I hope you find the solution. Be careful with those values you choose, because they can change considerably Nusselt values.

kamran651 · January 9, 2012, 06:40

Yes you are right..i was not setting the reference values correctly which are used for post processing..i figured that out...

Thanks Bro
Kamran.

November 29, 2011, 02:46	Surface Nusselt Number tooooo high	#1
kamran651 New Member Kamran Join Date: Nov 2010 Posts: 8 Rep Power: 16	Hi brothers, I have designed a 1m length rectangular 2D cylinder-type model with. the inlet is 0.125 m on the top, and the flow is in the -Y direction and moving along the x direction after impinging on the wall below..my question is i want to study the heat transfer and Surface Nusselt Number on the impinging wall, i am using 2ddp realizable k-e model and set all the values correctly..my concern is >>> the Surface nusselt number on the impinging wall is coming out to be in the range of 5000, whereas as previous studies or comparison, it should come out to be between 120-150. anyone has any idea.where i am going wrong.??? Help highly appreciated bets Regards.

January 9, 2012, 06:40	Thanks Bro...	#3
kamran651 New Member Kamran Join Date: Nov 2010 Posts: 8 Rep Power: 16	Yes you are right..i was not setting the reference values correctly which are used for post processing..i figured that out... Thanks Bro Kamran.

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January 9, 2012, 02:14		#2
CFDaniel New Member Join Date: Jan 2012 Posts: 1 Rep Power: 0	Hi, As far as I know, try to change the reference values given in the reference values menu. It doesnt need to start the simulation again. Those values only work for postprocessing. You may take: D as your hydraulic diameter T as your reference pressure Check it I hope you find the solution. Be careful with those values you choose, because they can change considerably Nusselt values.