Brian Stanley
2 November 2012
Keep the Heat/Thermodynamics
Overview
Thermodynamics
Event Parameters
Device Specifics
Preparing for the Written Test
What to Expect on Competition Day
Questions
What is it?
Definition:
Thermodynamics is the study of thermal energy along with how
it interacts with matter
Description:
Teams must construct an insulated device prior to the
tournament that is designed to retain heat. Students must also
complete a written test on thermodynamic concepts.
Event Overview
Build a device
Specific materials are prohibited (see official rules)
Creativity is encouraged
Test the device
Starting temperature of water
Volume of water
Time of test
Room temperature effects?
Study for written test
Topics listed on rules sheet
Device Specifics
Device MUST fit within 20 cm. cube (K.T.H.) or 15 cm.
cube (Thermo) when fully assembled
250 mL beaker must be easy to get to and remove
Once impounded, changes to the device CANNOT be made
No electrical devices, chemical reactions, other energy
source
Must have a hole (1.5 cm. diam.) in top for thermometer
Temperature Plots
Teams provide up to 4 plots that demonstrate the
performance of the device
Scoring
2 pts. if labeled with school and names
2 pts. for appropriately labeled axes and title
2 pts. for appropriate units
1 pt. for each data plot on a graph or graphs turned in (up to 4
total pts.)
Written Test
Topics:
Temperature conversion
Units of heat
Thermal conductivity
Heat capacity
Specific heat
Laws of thermodynamics
History/people of thermodynamics
Thermodynamic processes
General Test/Study Tips
3
-
ring binder permitted
No limit on size or content
Be practical
Organization is key
Limited time
Print pages
Organize by parent topic
Tabs are useful
Highlight specific equations and key terms/people
Books tend to be too complicated/specific
Sample Questions
What is 56
o
C in:
Fahrenheit
Kelvin
Rankine
How many BTU’s are in one gram calorie?
What is the specific heat capacity of dry air in J/g
-
K at 0
o
C?
Who is considered to be the Father of Thermodynamics?
Who is the Kelvin temperature scale named after?
What is the relationship between Heat Capacity and Specific
Heat?
Sample Questions
Competition questions may be:
Multiple choice
Fill in the blank
Matching
Short answer
Intent is not to trick students, but to test their knowledge of
basic thermodynamic principles
Practice solving these problems beforehand
What to Expect
One hour for impound
Expect a line
Hint
–
arrive early to make life easier
Have everything you need organized in a plastic container
Students are responsible for:
Device
2 identical 250 mL beakers
Eye protection (splash rated)
Plots
Writing utensils
Notes
Calculator
What to Expect
Event supervisors will provide:
Hot water
Devices for transferring water to device
Thermometers
Students may bring thermometers, if desired
Stop watches
Miscellaneous
Testing the Device
Competition and Testing:
Temperature (60
-
90
o
C), volume of water, and time (20
-
40
min.) is same for all teams
Announced after impound when all teams are in room
Teams given 5 min to setup/modify devices
Team must be ready to test when supervisor calls on them
Testing set up in staggered sequence
Division C teams have option of adding up to 50 mL of ice
water
Tips
NOT a performance building event!
Performance of device is only 25% of final score
Focus is on reliability and repeatability
Test, test, test and test some more!
Accuracy of predictions matters
Division C
–
If confident, go for the ice water bonus
Tips for Building
For Performance
Make interior tight to limit
convection heat transfer
Design for a pluggable hole
Use light materials with
good insulation properties
Balsa wood, sawdust
For Reliability
Line interior of device in
aluminum foil
Use sturdy materials
Think carefully about
fastening materials
together
Permanent is not always good
Devices must be easily
disassembled for inspection
What are the judges looking for?
Knowledge of rules
Knowledge of device
Do students know why materials were chosen?
Can students efficiently assemble device?
Creativity
Accuracy of temperature prediction
Confidence!
Questions?
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