[Reda.th]

Numerical simulation of flow in a tube (heat exchanger between water / solar
I am looking for how to calculate average nusseltte numbre in a tube in 3D?
I calculate that way but it gives the value 0
Report / Surface Integrals / Area-Weighted Average / Wall Fluxes / Surface Nusselt Number / I choose Surface_interne_tube_shadow / is give me the value 0
why?
Thank you.

[tas38]

Originally Posted by Reda.th

Numerical simulation of flow in a tube (heat exchanger between water / solar
I am looking for how to calculate average nusseltte numbre in a tube in 3D?
I calculate that way but it gives the value 0
Report / Surface Integrals / Area-Weighted Average / Wall Fluxes / Surface Nusselt Number / I choose Surface_interne_tube_shadow / is give me the value 0
why?
Thank you.

The Report -> Surface Integrals .... may be referencing an unspecified length scale (D) or an unspecified fluid conductivity (k_f), in the expression for average Nusselt number:

$ \overline{Nu} = \overline{h} D / k_f $

Just a guess.

Also you may want to try...

Report -> Surface Integrals -> Report Type -> Facet Average -> Field Variable (Wall Fluxes) --> Surface Nusselt Number....

[Reda.th]

I have dificult with Fluent,
I have simulation numirical in tube cylindric 3D but I do not know haw to calculate average Nusseltte number
if you have exmeples for tube 3D give me pleas
thank for you