Learning Forum

[atulsingh92]

Hello,

1 ) I wanted to know how is the nusselt number calculated in Fluent?
If I understand correctly, it should be Nu = hx D / k, however, if there is a comparaison to be made with equations such as Dittus Boelter and/or Sieder Tate, how do we know, should we compare with the former or the later?

2) HMT textbook suggests the hydrodynamic turbulent BL develops after x/D > 10, where x is the length of the length in question.
Now if I have a pipe length smaller than this value (periodic unit of a pipe, non axis symetrical because of helical cut around its periphery),
how then, would the nusselt number in fluent indicate a correct value along its wall, or it doesn't, and a  full pipe simulation is recommended instead?

[Rob]

If you look in the User Guide most (all?) of the post processing functions are defined: Field Function Definitions chapter.