[alimea]

Hi all,

I decide to present a correlation from Nu against Re for my special case of forced convection around a cylinder. However, I don't know which type of function is better?
Using polynomials gives us the best correlation with the lowest error, however they have an ugly appearance!
What are the criteria to present a correlation?

1- Is it important to use the simplest function or presenting a (for example) polynomial like:
Nu = A*Re^4+ B*Re^3 +...
with lower error, can be a nice choice ?

2- Can a piecewise function appropriate choice to decrease the errors?

Any other point?

Thanks,
Ali