natural convection

sofie1 · September 1, 2011, 03:56

Hi,
I need some help ,when i simulated with fluent the flow in a cavity with thefirst wall is heated and the second is adiabatic at low Rayleigh number, the calculation of the Nusselt number at the hot wall gives me double the values that of literature, what does this mean?

ravisalgar · September 1, 2011, 08:58

well i m not able to understand ur problem correctly, so can u describe your problem for which you r doing simulation.

sofie1 · September 2, 2011, 10:51

I have a square and a cylindeical closed cavity,the first vertical wall is heated and the second is adiabatic the horizontal walls top and bottom are adiabatic ,calculation of the Nusselt number of the vertical wall gives me values double of those in the literature.
is that is true that fluent calculate the flow in a wall on both sides?

Thanks

ravisalgar · September 2, 2011, 16:17

i feel nusselt number of vertical wall(square) that is outside must be equal to 1 as it is a solid part so mode of heat transfer will be conduction dominant...
Does the blind cylindrical cavity is filled with some fluid or is it in a state of vaccum?

sofie1 · September 2, 2011, 17:48

No the nusselt number of vertical wal is 'nt equal to 1 and in the closed cavity there is a fluid ( air) and i have two cases cylindrical and a square cavity

ravisalgar · September 2, 2011, 23:56

well good morning
hmmm can u attach your mesh file and the details of the boundary conditions need to be impemented in this particular problem as coz m not getting the problem definition clearly!!!!

September 1, 2011, 03:56	natural convection	#1
sofie1 Member sofia Join Date: Apr 2010 Location: world Posts: 31 Rep Power: 16	Hi, I need some help ,when i simulated with fluent the flow in a cavity with thefirst wall is heated and the second is adiabatic at low Rayleigh number, the calculation of the Nusselt number at the hot wall gives me double the values that of literature, what does this mean?

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September 1, 2011, 08:58		#2
ravisalgar New Member RAVI KUMAR Join Date: Aug 2011 Location: HYDERABAD Posts: 16 Rep Power: 14	well i m not able to understand ur problem correctly, so can u describe your problem for which you r doing simulation.

September 2, 2011, 10:51		#3
sofie1 Member sofia Join Date: Apr 2010 Location: world Posts: 31 Rep Power: 16	I have a square and a cylindeical closed cavity,the first vertical wall is heated and the second is adiabatic the horizontal walls top and bottom are adiabatic ,calculation of the Nusselt number of the vertical wall gives me values double of those in the literature. is that is true that fluent calculate the flow in a wall on both sides? Thanks

September 2, 2011, 16:17		#4
ravisalgar New Member RAVI KUMAR Join Date: Aug 2011 Location: HYDERABAD Posts: 16 Rep Power: 14	i feel nusselt number of vertical wall(square) that is outside must be equal to 1 as it is a solid part so mode of heat transfer will be conduction dominant... Does the blind cylindrical cavity is filled with some fluid or is it in a state of vaccum?

September 2, 2011, 17:48		#5
sofie1 Member sofia Join Date: Apr 2010 Location: world Posts: 31 Rep Power: 16	No the nusselt number of vertical wal is 'nt equal to 1 and in the closed cavity there is a fluid ( air) and i have two cases cylindrical and a square cavity

September 2, 2011, 23:56		#6
ravisalgar New Member RAVI KUMAR Join Date: Aug 2011 Location: HYDERABAD Posts: 16 Rep Power: 14	well good morning hmmm can u attach your mesh file and the details of the boundary conditions need to be impemented in this particular problem as coz m not getting the problem definition clearly!!!!