Nusselt numbers for a shell and tube heat exchanger

[jkf]

Hallo, CE friends.
I am mechanical engineer and a new member of this Forum, and I need your help for the design of a shell and tube heat exchanger which is needed to keep the temperature of a water pool below a set value.
The component is a counter-flow heat exchanger with single pass in the tube and shell sides, without baffles. For the tube side I am using the Gnielinski equation (turbulent flow): Nu=((f/8*(Re-1000)*Pr)*(1+((di/L)**2/3)))/(1+12,7*(f/8)**1/2*(Pr**2/3-1)), where the friction factor is f=(1,82*logRe-1,64)**(-2).
My difficult consists in determining the Nusselt correlations which better apply to the shell side. I think I could likewise use the same above correlation for the longitudinal region of the shell, of course considering now the eq. hydraulic diameter. Should the use of this equation be correct?
And what are the best Nu correlations to be used for the cross flows in the regions of the inlet and outlet nozzles, and what is the contribution (weights) of each of these Nusselts (logitudinal and cross flows) in the resulting Nusselt of the shell side? How are these weights achieved (calculated)? Are they a function of the heat exchanger geometry?

Any help will be appreciated.
I thank you in advance for helping me in this matter.

jkf

[Elisa]

No answer yet. All the best jkf.

[jkf]

Thank you, Elisa.

jkf