Heat transfer

(Difference between revisions)

Revision as of 12:40, 1 December 2005

                     == Conduction ==

Conduction can be defined as the heat transfer through a substance because of a temperature gradient. The rate of heat transfer by conduction between two regions of a substance is proportional to the temperature difference between them. The constant of propotionality is called thermal conductivity of the material.

$Q_{Conduction} = -k*A*\frac{dT}{dx}$

Where

$Q = \mbox{Heat conducted}\;[W]$

$k = \mbox{Thermal conductivity of the material}\;[W/m\,K]$

$A = \mbox{Cross-sectional area of the object parallel to heat conduction}\;[m^2]$

$T = \mbox{Temperature}\;[K]$

$x = \mbox{Length of the object}\;[m]$

@@ Line 4: / Line 4: @@
 *Mathematically, it can be described by using the Fourier's law:
-:<math>
+:<math>Q_{Conduction} = -k*A*\frac{dT}{dx}</math>
-                Q_{Conduction} = -k*A*dT/dX
-</math>
 Where
+:<math>Q = \mbox{Heat conducted}\;[W]</math>
-      Q = Heat conducted (W)
+:<math>k = \mbox{Thermal conductivity of the material}\;[W/m\,K]</math>
+:<math>A = \mbox{Cross-sectional area of the object parallel to heat conduction}\;[m^2]</math>
-      k = Thermal conductivity of the material (W/m-K)
+:<math>T = \mbox{Temperature}\;[K]</math>
+:<math>x = \mbox{Length of the object}\;[m]</math>
-      A = Cross-sectional area of the object parallel to heat conduction (m2)
-      T = Temparature (K)
-      X = Length of the object (m)
 == Convection ==