The Significance of Fourier Number: Understanding Heat Conduction in Solids

[New2thermodyn]

What is Fourier number??

What exactly is Fourier number? I kno its Thermal diffusivity*time/square of radius. But what exactly is the meaning of Fourier number?

For eg: Why do we calculate Fourier number for finding out the lumped heat in solids?

 

[mathman]

http://en.wikipedia.org/wiki/Fourier_number

Try the above.

 

[New2thermodyn]

http://en.wikipedia.org/wiki/Fourier_number

Try the above.

Thanks Mathman, and yes,Of course iv checked wikipedia b4 posting that question! In wiki it is just the explanation of the terms involved, ie"the ratio of the heat conduction rate to the rate of thermal energy storage", is not that pretty obvious just looking at the equation? but what i want to know is the significance of the equation

 

[mathman]

Sorry - I can't help you any more.

 

[Mapes]

When the Fourier number is much larger than one, the conduction process is predicted to have reached steady state. Does this answer your question?

 

[blacktail]

Thanks Mathman, and yes,Of course iv checked wikipedia b4 posting that question! In wiki it is just the explanation of the terms involved, ie"the ratio of the heat conduction rate to the rate of thermal energy storage", is not that pretty obvious just looking at the equation? but what i want to know is the significance of the equation

Fo = (Heat conduction rate)/(thermal energy storage rate)
Fo = [k A [STRIKE]dT[/STRIKE]/dx]/[(dm/dt)*Cp*[STRIKE]dT[/STRIKE]] -------------> dx = L
Fo = [kA/L]/[ρ*Cp*Q] -----------------------> A/Q = t/L
Fo = [kt]/[ρ*Cp*(L²)]---------------------->k/ρ*Cp = α
Fo = αt/L²