Fourier Number

Fourier number, abbreviated as Fo, also called Fourier modulus, a dimensionless number, is the ratio of heat conduction rate to the rate of thermal energy storage in a solid.  This is mainly used in unsteady state heat transfer.

 

Fourier number calculator

Fourier number formula \(\large{ Fo = \frac{\alpha \; t_c }{l_c^2  }  }\)  Where:  Units English Metric \(\large{ Fo }\) = Fourier number \(\large{ dimensionless }\)   \(\large{ l_c }\) = characteristic length \(\large{ ft }\) \(\large{ m }\) \(\large{ t_c }\) = characteristic time \(\large{ sec }\) \(\large{ s }\) \(\large{ \alpha }\)  (Greel symbol alpha) = thermal diffusivity \(\large{\frac{ft^2}{sec}}\)  \(\large{\frac{m^2}{s}}\)