[mehyan]

dear friends,



would u do me a favor,
i realy stoped whit a problem,

i do not know exactly how i can create a expression for average nusselt number,
somebody says it like below but i still could not understand their meaning:



Replace nuL= (Wall Heat Flux *shoa*2[m])/(75 [K]*Thermal Conductivity )

with

nuL = areaAve(Wall Heat Flux)@Wall * shoa ..... * areaAve(k)@Wall




could u send me the complete expression of average nusselt number?
(whit obvious explanation so that i could apply it)


i want to use this in double pipe heat exchanger


Thanks in advance.

[ghorrocks]

You better understand what Nusselt number is first before you try to derive an equation to calculate it. Have a look in a heat transfer textbook.

And please do not spam me with private messages which are exact copies of posts on the forum. I do not like that.