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Introduction
Heat Fin ConductionEngine applicationHeat exchanger applicationOptimizing size and material
ObjectiveDetermine the optimum size and material for
a metal cooling finCompare IR thermometer and Thermocouple
for measuring fin surface temperatures
Safety PrecautionHot Plate
Do not touch the hot plate with bare hands Use the thermo glove to handle hot plate and fins
Do not store volatile flammable materials near a hot plate
Limit use of older hot plates for flammable materials.
Hot FinDo not place on combustible materialsDo not touch with handMake sure to place it where individual can not burn
themselves.
Material and Apparatus
• Hot plate• Copper, aluminum, steel tall and short fins with
hash marks• Hand-held thermocouple• IR thermometer• Thermal gloves
ProceduresPlug in hot platePlace fin on hot plateOrient fin so temperature measurements can
be made easily on the large fin.Set control on hot plate to “200”.
Recommended to use the thermocouple to check temperature
Use thermocouple to measure the temperature along the fin at 1-inch increments (hash marks)The temperature must be at steady state
Procedures Cont.Repeat step 4 until steady state is reached
Group members are responsible for choosing the appropriate sampling interval for temperatures.
When steady state has been achieved, measure the temperature at each hash markUse both thermocouple and IR thermometer
With the Thermal GlovesRotate the fin (if necessary) and measure the temperature
profile in short fin Using both thermocouple and IR thermometers
Remove the fin Safely place fin where people are unlikely to burn themselves. Do not place fin on combustible material
Repeat steps 2-9 for each pair of fin
Comparison of the Three Materials
0.000.100.200.300.400.500.600.700.800.901.000
0.2
0.4
0.6
0.8
1Theoretical Temperature Profiles
Stainless Steel Copper AluminiumDimensionless Length
Dim
en
sion
less
Tem
per-
atu
re
Comparison Cont.
0.00
0.20
0.40
0.60
0.80
1.00
0.00
1.00
Aluminum Long Fin
ThermocoupleIRTheoretical
Dimensionless Length
Dim
en
sion
less
T
em
pera
ture
0.00
0.20
0.40
0.60
0.80
1.00
0.00
1.00
Aluminum Short Fin
ThermocoupleIRTheoretical
Dimensionless Length
Dim
en
sion
less
T
em
pera
ture
Comparison Cont.
0.00 0.20 0.40 0.60 0.80 1.000
1
Copper Long Fin
ThermocoupleIRTheoretical
Dimensionless Length
Dim
en
sion
less
T
em
pera
ture
0.00 0.20 0.40 0.60 0.80 1.000
1
Copper Short Fin
ThermocoupleIRTheoretical
Dimensionless Length
Dim
en
sion
less
T
em
pera
ture
Comparison Cont.
0.00
0.20
0.40
0.60
0.80
1.00
0.00
Stainless Steel Long Fin
ThermocoupleIRTHeoretical
Dimensionless Length
Dim
en
sion
less
T
em
pera
ture
0.00 0.20 0.40 0.60 0.80 1.000.000.200.400.600.801.00Stainless Steel Short
Fin
ThermocoupleIRTheoretical
Dimensionless LengthD
imen
sion
less
T
em
pera
ture
Comparison Cont.
Thermocouple IR0.00
100.00
200.00
300.00
400.00
500.00
600.00
700.00
800.00
900.00
1000.00
Rate of Heat Removal Long Fin
AluminiumCopperStainless Steel
BT
U/h
r
Thermocouple IR0.00
100.00
200.00
300.00
400.00
500.00
600.00
700.00
800.00
900.00
1000.00
Rate of Heat Removal Short Fin
aluminiumCopperStainless Steel
BT
U/h
r
Discussion: Best MaterialCopper had the most rate of heat transfer
and a better temperature profile.Not widely used
Costly Corrosive
Aluminum had the second highest heat transferWidely used
Cost Effective Less Corrosive
SizeTheoretically, the larger the surface area of
the fin, more heat is removed.Experimentally this was not the case.
Error may be caused by the corrosion on the fin Human Error
Thermocouple or IRThermocouple
Experimental data was closer to the theoretical values.
Reading is done upon contact on the surface.IR
Experimental and theoretical data had major discrepancies.
Reading was dependent on the amount of energy will emit.
ErrorMaterial
Oxidation The darker spots on the fin effected the temperature with
IR thermometer.Hash mark were not visible on Copper fin.
HumanNot having a steady hand to measure the temperature
with IR Thermometer and Thermocouple.Inaccurately measuring the fins.
Not picking the same measuring points
EquipmentInaccurate reading with the two devices.
ConclusionCopper is the best material to be used as a
cooling fin.Highest rate of heat removal
Aluminum is widely used material Cost effectiveLess corrosive
Thermocouple is a more reliable device to measure the heat fin’s dispersion of heat.Contact with the metal gave a more accurate
reading
Referencehttp://cnx.rice.edu/content/m10205/latest/http://www.mapleapps.com/categories/
mathematics/desolving/html/coolf6-.htmlhttp://enstrophy.colorado.edu/~mohseni/
ASEN3113Fall2002/FinEqDerivation1.pdf“Transport Processes and Separation Process
Principles”, 4th ed., C.J Geankoplis, (Prentice-Hall, New Jersey), 2003. ISBN 0-13-101367-X.
“Elementary Differential Equations and Boundary Value Problems,” 4th ed., W. E. Boyce and R. C. DiPrima, (John Wiley & Sons, New York), 1986.
“Numerical Methods for Engineers,” 5th ed., S. C. Chapra and R. P. Canale (McGraw-Hill, New York), 2006. ISBN 0-07-310156-7.
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