Forced convection heat transfer in low prandtl number turbulent flows: Influence of axial conduction

The effect of axial conduction was investigated for turbulent heat transfer in a round pipe with uniform wall temperature. Exact solutions were obtained by using the method of separation of variables for the two cases with and without the axial conduction term. The solutions show that the effect of axial conduction is important at low Peclet numbers, say Pe < 100, but negligible in the thermally fully‐developed region. Also, the fully developed Nusselt numbers depend only on Reynolds number at low Peclet numbers and the interpolation formula is proposed:\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm Nu}_x = 2.77{\mathop{\rm Re}\nolimits} ^{0.0656} $$\end{document}which fits the calculated data well in the liquid metal range 0.001 < Pr < 0.022 for Pe < 100.