(1)EML 4304L Thermal Fluids Lab
Thermal Conduction
Experiment #3
Teaching Group #3: Christopher Hokes, Ryan Prentiss, Chris Bolyard, Fredrick Davidson, and Siye Baker
Home Objectives Background Testing Equipment Pictures Procedure Questions Links
All temperatures within the bars, the water
temperatures and the water flow rates are recorded under equilibrium conditions.
The rate of heat flow at the heat sink is given by
(1)
where
mw =
mass of cooling water displaced in time Dt
Cp
= Specific heat of water at constant pressure
DTw
= (Tout - Tin) of cooling water
Dt
= time required to displace a volume Vw
of water
Derivation of
Fourier's law
A
functional relationship can be established between the rate of heat transfer and
the temperature difference, length of travel and the cross-sectional area.
This is the well-known Fourier's law of heat conduction
(2)
where K is the proportionality constant known as the
coefficient of thermal conductivity, A
is the cross-sectional area, Dx
is the distance and q is the heat
rate, which is obtained from Equation 1.
Thermal Contact
Resistance
The thermal contact resistance is directly
proportional to the temperature gradient and inversely proportional to the heat
flux, as indicated by the following equation
(3)
where
DT
the temperature jumps across the contact point, and q is the heat transfer rate.