Nusselt Number

on . Posted in Dimensionless Numbers

Nusselt number, abbreviated as Nu, a dimensionless number, describes the ratio of convective heat transfer to conductive heat across a boundary.

 

Nusselt number formula

\(\large{ Nu = \frac{h \; l_c}{k}   }\) 
Symbol English Metric
\(\large{ Nu }\) = Nusselt number \(\large{dimensionless}\)
\(\large{ l_c }\) = characteristic length \(\large{ft}\) \(\large{m}\)
\(\large{ h }\) = heat transfer coefficient \(\large{\frac{Btu}{hr-ft^2-F}}\)  \(\large{\frac{W}{m^2-K}}\)
\(\large{ k }\) = thermal conductivity \(\large{\frac{Btu-ft}{hr-ft^2-F}}\) \(\large{\frac{W}{m-K}}\)

 

Nusselt number calculator

 

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Tags: Heat Transfer Equations Thermal Conductivity Equations Heat Equations