[mariam.sara]

hi thanks sfalsharif for your interests about the subject. I mentioned a note about what you mentioned in reply #17 above pls have a look thanks.

Originally Posted by sfalsharif

Hi Mariam,
I realize this thread is a bit old now, but can you explain further what you mean by the above statement? If your case is not fully developed it is not surprising that you would get a higher Nu than the theoretical result for fully-developed conditions. The temperature profile is flatter in the developing region, and the difference between the bulk temperature and the wall temperature is smaller than in the fully developed region. For a given fixed wall heat flux, this means h will be higher in the developing region. So it is important to use periodic conditions for temperature, not just velocity.