# Page History

## Key

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The table below shows the list of the popular dimensionless numbers related to heat transfer.

Nusselt Number

LaTeX Math Inline
body --uriencoded--\displaystyle %7B\rm Nu%7D =\frac%7BU \cdot L%7D%7B\lambda %7D

characterizes heat exchange rate with fluid convection
Biot Number

LaTeX Math Inline
body --uriencoded--\displaystyle %7B\rm Bi%7D =\frac%7BU \cdot L%7D%7B\lambda %7D

characterizes heat exchange rate with solid bodies
Prandtl number

LaTeX Math Inline
body --uriencoded--\displaystyle %7B\rm Pr%7D = \frac%7B\nu%7D%7Ba%7D

characterizes fluid in terms of its ability to develop heat convection against heat conduction
Grashof number

LaTeX Math Inline
body --uriencoded--\displaystyle %7B\rm Gr%7D = \frac%7Bg \, \beta \, \Delta T \, L%5e3%7D%7B\nu%5e2%7D

characterizes the natural heat convection due to gravity
Rayleigh number

LaTeX Math Inline
body --uriencoded--\displaystyle %7B\rm Ra%7D = %7B\rm Gr%7D \cdot %7B\rm Pr%7D

characterizes the natural heat convection due to gravity
Fourier number

LaTeX Math Inline
body --uriencoded--\displaystyle %7B\rm Fo%7D = \frac%7Ba \cdot t%7D%7BL%5e2%7D

dimensionless time