Editing Heat transfer coefficient (section)

====Internal flow, laminar flow====
Sieder and Tate give the following correlation to account for entrance effects in laminar flow in tubes where <math>D</math> is the internal diameter, <math>{\mu }_{b}</math> is the fluid viscosity at the bulk mean temperature, <math>{\mu }_{w}</math> is the viscosity at the tube wall surface temperature.<ref name="Welty"/>

:<math>\mathrm{Nu}_{D}={1.86}\cdot{{{\left( \mathrm{Re}\cdot\mathrm{Pr} \right)}^{{}^{1}\!\!\diagup\!\!{}_{3}\;}}}{{\left( \frac{D}{L} \right)}^{{}^{1}\!\!\diagup\!\!{}_{3}\;}}{{\left( \frac{{{\mu }_{b}}}{{{\mu }_{w}}} \right)}^{0.14}}</math>

For fully developed laminar flow, the Nusselt number is constant and equal to 3.66. Mills combines the entrance effects and fully developed flow into one equation

:<math>\mathrm{Nu}_{D}=3.66+\frac{0.065\cdot\mathrm{Re}\cdot\mathrm{Pr}\cdot\frac{D}{L}}{1+0.04\cdot\left( \mathrm{Re}\cdot\mathrm{Pr}\cdot\frac{D}{L}\right)^{2/3}}</math><ref>{{Cite web |url=http://web2.clarkson.edu/projects/subramanian/ch330/notes/Heat%20Transfer%20in%20Flow%20Through%20Conduits.pdf |title=Heat Transfer in Flow Through Conduits |last=Subramanian |first=R. Shankar |website=clarkson.edu}}</ref>