bulk local temperature
 

hi foamer
i would like to calculate nusselt in axisymmetric pipe, T reference in nusselt equation is local bulk mean temperature, how can i calculate it?

The bulk temperature is usually calculated by setting y+=250 in turbulent wall temperature function.

you may find some clue at
B.U. Bae, H.Y. Yoon, D.J. Euh, C.H. Song and G.C. Park, Computational analysis of a subcooled boiling ow with a one-group interfacial area transport equation", J. Nucl. Sci. Technol. 45, 341 (2008)

thank you, i will look at it ;) but my case is in a micro channel :) and its laminar !!!

hi, to calculate bulk temperature you create a plane and calculate mass weighted average of temperature in this plane.
i hope it help you.
i has a problem in my results can any one help me?
i has a micro channel and i calculate bulk and average temperature in order to calculate Nu on a micro channel. my problem is that i obtained a bulk temperature larger than average temperature which lead to negative Nu value. can any one help me?