Fourier Number

Fourier Number

In physics and engineering, the Fourier number (Fo) or Fourier modulus, named after Joseph Fourier, is a dimensionless number that characterizes heat conduction. Conceptually, it is the ratio of the heat conduction rate to the rate of thermal energy storage. Together with the Biot number, it characterizes transient conduction problems. It is defined as:

where:

  • α is the thermal diffusivity
  • t is the characteristic time
  • R is the length through which conduction occurs

For transient mass transfer by diffusion, there is an analogous mass Fourier Number (also denoted Fo) defined as:

where:

  • "D" is the Diffusivity
  • "t" is the characteristic timescale
  • "L" is the length scale of interest

Read more about Fourier Number:  Using Fourier Number

Famous quotes containing the word number:

    Cole’s Hill was the scene of the secret night burials of those who died during the first year of the settlement. Corn was planted over their graves so that the Indians should not know how many of their number had perished.
    —For the State of Massachusetts, U.S. public relief program (1935-1943)