Fourier Number

Compute the time-to-diffusion scale ratio in transient heat conduction.

visual calculatorHeat Transfer

Read the flow shape before trusting the number.

This page turns a CFD setup into regime, scale, and dominant-effect cues. Adjust the calculator below and compare the moving graphic with the computed result.

input scale

model

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Fouriertransient conductionheat equation

formula

KaTeX rendered

\begin{aligned}\text{Fo = alpha t / L\^{}2}\end{aligned}

ASCII source

Fo = alpha t / L^2

alpha (m^2/s)time t (s)length L (m)

0.2500

diffusion stage

moderate penetration

Fourier number helps judge how far a thermal disturbance has diffused relative to the body size or mesh scale.

Fourier transient conduction heat equation