TEMPERATURE
DISTIRBUTION
Table of content
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Abstract
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Page
3
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Objectives
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Page
3
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Theory
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Page 3
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Design Matrix
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Page
4
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Testing
Method
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Page 4
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Procedure
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Page
5
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Discussion
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Page 6
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Results
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Page
7
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Conclusion
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Page 10
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Recommendation
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Page
10
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Sources
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Page 11
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Table of Figures and Charts
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Table 1 – Design
Matrix
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Page 4
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Figure 1 – Procedure Picture
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Page
5
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Figure
2 – Procedure Picture
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Page 5
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Figure 3 – Procedure Picture
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Page
6
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Figure
4 – Procedure Picture
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Page 6
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Chart
1 – Glass Pan Result
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Page
7
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Chart 2 – Stainless
Steel Pan Results
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Page 8
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Chart 3 – Aluminum
pan Results
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Page
9
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Figure
5 – Final Ranking of Pans
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Page 10
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Abstract
For collage
students, time and saving money by home cooking is an important aspect of the
student’s life style. However, there are a wide variety of cooking ware that
one can choose from, and as a student, try and fail with cooking ware is not an
option. So, in this project, the team will conduct an experiment to know which
cooking ware material is better for a student. In the lab, we found a glass, an
aluminum and a stainless steel pans. So we used those pans to conduct our
experiment.
Objectives
The team set three goals to meet for this project, the were chosen
to meet the requirement of the project
·
To Design a full factorial experiment, which
consists of two or more factors that the whole experiment is based on.
·
Minimizing
the percentage of errors, through making a design matrix to make it is easier
to find the testing method with the least amount of error possible
·
Find
A clear answer to the Hypothesis of the project, The results of the experiment
should answer the experiment’s main question or meets its main objective.
Theory
A quick research
was done to know the thermal conductivity of each material. The Glass has the
lowest thermal conductivity of only 0.8 W/m.K, which makes it the slowest heat
distributor among the other materials. The Stainless steel’s thermal
conductivity is 45 W/m.K and the Aluminum pan’s thermal conductivity is the
highest at 204 W/m.K which make it the best at heat distribution. So, based on
the thermal conductivity numbers, the team hypothesized that the Aluminum pan
is the best out of the other two pans.
Design Matrix
To insure the
safest testing method, the team came up with the following criteria. Each
criteria has two options, based on our rating of the options, the team graded
them in a scale out of 10 grades, the grade is distributed between the two
options under each criteria.
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1
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Measuring Tool
The Tools the team will use to
measure the temperature of the pan.
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The Grade
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A
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Thermocouple
Easier
to collect data through DAQ.
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7
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B
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Thermometer
Data
Collection is manual.
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3
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2
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Point of contact
The number of testing points on the
pan’s surface.
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A
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One
Point Of contact
Not
accurate, since temperature can differ from the center to the edge of
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2
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B
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Two
Points of contacts
More
accurate in measuring the temperature distribution.
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8
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3
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Test environment
The pan should be full of water or
should be empty.
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A
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The
Pan is Full of Water
Water
can affect the heat process.
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4
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B
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Testing
with an Empty pan
Measuring
the real temperature of the pan’s surface is more accurate.
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6
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Table 1 - Design Matrix
Testing Method
After the design
matrix was made, the team knows which testing method they will use. First of
all, the team will use a thermocouple type G that is found in the lab. Because
using thermocouple allows to take measurement in a more productive way, the
team not only can measure temperature continuously over a long period of time,
but also can associate each temperature with time which will come in use later
in the result. The second criteria was the points of contact, and the team
chose two points of contacts, so the team can measure the temperature more
diversely which will result in precise results of the real heating process.
Finally, the team chose to have the pan empty, since that will allow to get
results of the surface of the pan without exterior impacts.
Procedure
The team
gathered all the needed tools to conduct the experiment. The team used two
wires of thermocouple type G, and used the Data Acquisition device – DAQ – to
record the temperature of the pans. The team used three pans that were found in
the lab, the pans also are very widely used in the real environment of cooking.
Also, the team used a hot plate found in
the lab as well. The only thing that was used from outside the laboratory is
the glue – Permatex Ultra Copper Sensor Safe High-Temp RTV silicone-.
The team used two channels of the DAQ device, one is connected to
the thermocouple that reads the temperature of the center of the pan, the other
channels is connected to the thermocouple that reads the temperature of the
edges or the outer diameter of the pan. The thermocouples were glued using the
Ultra copper sensor safe high temp glue, they were glued to their proper place
prior to the heating process. The glued was left for a convenience time to make
sure it functions at its maximum before the heating process.
The hot Plate was sat on its 10th level of heating, and
it was allowed to preheat for 3 minutes each time before placing the pans on
top of it. Each pan was let to stay for three minutes on high temperature
before the heating process was cut off. The software used to record the
temperature and time readings is National Instruments, and the proper
adjustments was made to the software settings before starting the recording
task. After each pan was tested, the hot plate was left to preheat again, and
the same process was repeated with each pan. The Pan initial temperature is the
same as the room temperature, around 21 C degrees.
Figure 3 - The Thermocouple were
connected to DAQ channels to import information to Excel
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Figure 4- The tested pans and the
Hot plate used in the test
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Discussion
To decide the
best tested material, two factors were taken into account :
·
Delta
T (ΔT) which is calculated through subtracting the two temperatures at
the end of the heating process.
·
Heating
time, the team measured the time every pan took to reach water boiling
temperature (100 C) in both points of contact. The shorter the better.
The resulted number of ΔT is compared with other Delta Ts of the other pans, to figure out
the best one with heat distribution. The Highest number is the worst pan, it
basically means that the difference in temperature was big between the two
points of contact. The smallest the better, because the difference is not high
which insures better heat distribution. Heating time, is an important factor
that we built our experiment on, because the time is important in our
situation. The team converted the heating time from minutes to seconds, so an
actual number is resulted. The team then can add the resulted number to the
Delta T of each pan and get one Final Number. The higher the delta number, the
worse the heat distribution. The longer the time, the slower the desired
temperature is reached. So, the higher the final number (the score) is, the
worse the pan.
The results
·
The
Glass Pan’s chart
Chart 1 - Glass pan heating chart
The results of the Glass pan is quit steady, however the edges of
the pan started to gain more heat faster the center of the pan and our
measurement started with the edges being15 degrees ahead of the center of the
pan, that difference was mainly kept the same through the whole time, however
toward the middle, the center of the pan started to gain heat even slower, so
when the test ended after 3 minutes and 3 seconds, the edge of the pan was
147.7 C degrees while the center was 189.9 C degrees. Delta T for the glass pan
is 42.2 C Degrees. Also, It took the glass pan 1 minute and 54 seconds to reach
our desired temperature of 100 C degrees.
·
The
Stainless Steel’s pan chart
Chart 2- The Stainless Steel’s pan chart
The stainless steel curve is quite
similar to the glass’s pan curve. The Edge started to gain heat faster, and
rose from 22 degrees to 180 C degrees very fast, the increment started to slow
down until our time limit was reached. The center of the pan’s increment was
smother than the edge, the increment of the temperature was almost the same
trough out the testing period. The stainless steel edge temperature was 209.1 C
degrees at the end of the test and the center was 182.15 C degrees. The
difference is 26.9. Delta T of the
stainless steel pan is 26.9 C degrees. The time it took the center and the edge
to reach 100C is 1 minutes and 26 seconds.
·
The
Aluminum Pan’s chart
Chart 3- The Aluminum Pan's chart
The Aluminum pan’s curve is more interesting than the Glass pan’s
curve. The center and the edges of the pan started from the same temperature
which was 21 C degrees. The edge of the pan was gaining heat faster than the
center, and towered the middle of our three minutes time limit the center and
the edges all met at the same temperature at 110.8 C degrees. The Edges
increment started to decrease, and the center’s increment started to increase
and they ended up at a difference of 19 C degrees. The center was 171.36 C
degrees and the edge was 152.27 C degrees. Delta T of the Aluminum pan is 19 C degrees. The
time it took the center and the edge to reach 100 C degrees is 1 minutes and 16
seconds.
The crossing lines in this graph is believed to be happened due to a
movement of the pan, the pan was shifted to the side a little. And since the
hot plate’s burner is ring shaped, the sensor on the center was actually right above
the burner at that stage. However, the other two charts of the glass and the
stainless steel pans are similar. The sides of the pan is always higher in
temperature than the center, because of the ring shaped burner of the hotplate.
Conclusion
After displaying all the charts above, the best pan is the Aluminum
pan. It has the best heat distribution out of the other pans, also it reached
our goal temperature of 100 C degrees faster than the other pans. The Aluminum
Pan gained 95 points. Second comes the Stainless steel pan with 112.9 points,
it is second in heat distribution and time consuming. It took 86 seconds to
reach 100C degrees. The Last pan in our ranking is the glass pan, it has the
highest difference of temperature among all pans, with 42.2 C degrees, also it
took 114 seconds to reach 100 C degrees. That resulted 156.2 points to the
glass pan. As the team hypothesized, the aluminum pan is the best among all
tested pans.
Recommendations
The experiment’s lay out led to successful results, the team
benefited from the design matrix at the beginning. Even though the design
matrix slowed down the work, however it turned out to be great help during the
process. The planning of the experiment helped the team meeting every
objective. However, there were things that could have been done better. First,
the results could have been more interesting if the temperature of the actual
hot plate was known. Also, careful placing of the pans is recommended, as it
was observed the team has had a misplacement error in the aluminum pan’s test.
Finally, it is recommended to have a hot plate with a flat surface so the heat
of the burner is equally distributed.
Recourses
IN
THESE SERIES OF ESSAYS THAT I AM POSTING, I WANT TO SHARE MY WRITINGS FROM MY
STUDY AT THE UNIVERSITY OF DAYTON. I WANT TO SHARE SOME OF THE KNOWLEDGE I
OBTAINED, THESE ESSAYS ARE FROM DIFFERENT CLASSES SOME ARE TECHNICAL AND SOME
ARE PHILOSOPHICAL AND CREATIVE WRITINGS.
