Keep the Heat/Thermodynamics
Brian Stanley
2 November 2012
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.
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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 56oC 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 0oC?
 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:
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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 (60-90oC), 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
 For Reliability
 Make interior tight to limit
 Line interior of device in
convection heat transfer
 Design for a pluggable hole
 Use light materials with
good insulation properties
aluminum foil
 Use sturdy materials
 Think carefully about
fastening materials
together
 Balsa wood, sawdust
 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?