flow in isothermal pipe nusselt number calculation
 

Hi,

I am working on laminar flow in 3D isothermal pipe and trying to calculate nusselt number. For laminar flow case: the Nusselt number should be 3.66, however am getting values in hundreds. I am ploting with Reports-surfaceintergals-wall fluxes-nusselt number.

Can some one please advise me how to calculate the mean temperatures and nusselt number?

Thanks,