Development of a Modern Thermal Systems Design Laboratory – An Update

1. Development of a Modern Thermal Systems Design Laboratory – An Update John Abbitt – Senior Lecturer Dept. of Mechanical & Aerospace Engineering University of Florida

2. Background • ABET accredited Mechanical Engineering programs are required to provide laboratory and design experiences in their curriculum. • In 2005, MAE made commitment to hire lecturers whose sole job was to manage and conduct labs. • I was hired in Spring 2006 to teach EML4304C, Thermo-Fluids Design and Lab, and EML4147C, Thermo-Heats Design and Lab

3. Course Topics – EML4304C • Thermo-Fluids Design and Lab • Pipe flow • Pumps • Compressible flow • Rocket thrust • Refrigeration • Combustion

4. Course Topics – EML4147C • Thermo-Heats Design and Lab • Heat exchangers • Gas mixtures – Cooling Towers • Heat transfer by boiling and condensation • Radiation • Conduction heat transfer

5. Class structure • Each class consists of: • Approximately 110 students in each class, 220 total • Classes offered Fall, Spring, Summer semester • Two classroom lectures per week • Five pre-labs with on-line assessment • Laboratory with lab report • Twenty five lab periods per week, 8 students in each section (8 in heats, 6 in fluids) • Eight homework assignments • Two in-class tests • Final design project and oral/written report

6. Experiments: Thermo-Fluids Pipe loss experiment (constructed in-house) – students measure the head loss due to friction in selected pipes and fittings at different flow rates. From the data, students determine friction factors. Fan performance lab – Students measure the head gain at various flow rates, and rpm’s and torque of a fan. Using the data, students develop a fan performance curve which is used to determine the correct size of a fan or pump for a given piping system.

7. Experiments: Thermo-Fluids Tank discharge lab – Students learn the principles of compressible flow and develop the theory of a choked orifice flow meter. Pressure and temperature are measured in a large tank at one millisecond intervals . Hydro-rocket lab - Students learn to calculate the thrust from a rocket nozzle. The thrust is measured using a high speed pressure transducer and load cell .

8. Experiments: Thermo-Fluids Refrigeration lab - Students learn the thermodynamics of the various refrigeration cycles. By measuring temperature, pressure, and flow rates at various points in the cycle, students calculate the performance and power requirements of an air-conditioner. Students manually record the temperature and pressures at the different state points.

9. Experiments: Thermo-Heats Heat Exchanger Lab – Students analyze a concentric double-pipe heat exchanger by measuring inlet and outlet temperatures of the two fluids as well as their flow rates. From this information, students calculate the heat flux and overall heat transfer coefficient. Radiation Lab - Students measure the radiation heat transfer from an oven at various distances. By comparing the measurements with theoretical predictions, students can determine the emissivity of the oven as well as the performance of the detector.

10. Experiments: Thermo-Heats ←Cooling Tower Lab - Water is cooled by the evaporation of a small portion of the total flow. Air enters at the bottom of the tower and flows upward increasing its moisture content while the water is cooled through evaporation. Pool Boiling Lab - The → apparatus in this lab is a small-scale version of the equipment used to maintain the temperature of materials found in such places as in the core of a nuclear power plant.

11. Experiments: Thermo-Heats Heat Conduction – Students are taught the principles of linear and radial heat conduction and how to use that theory to measure heat flux. They learn how to find contact resistance and how to determine the thermal conductivity of various materials. Thermal circuit diagrams are emphasized.

12. Experiments: Wind Tunnel

13. The Dilemma • Courses are time-consuming • Faculty are not rewarded for teaching (at UF and other research institutions, especially undergraduate courses) • Courses are expensive

14. The Solution • Hire an instructor whose sole duties are teaching the courses and reward the instructor based on performance in the courses • Charge lab and equipment fees

15. Instructor duties: Course Management • Lecture • Web site • Sakai • On-line videos • Teaching assistants (5 grad, 4 undergrad) • Log books

16. Website

17. Sakai: used for pre-labs • Video of lecture and lab demonstration • Pre-lab assessment using Sakai

18. Log books • All tests and lab reports are logged in by either instructor or TA

19. Solution to the expense: Lab and Equipment Fees • Lab fee - $45 per student per semester to cover the cost of expendables (≈ $9000 for the two classes • Equipment fee – approximately $200 per student per semester to cover the cost of capital equipment and maintenance (≈ $40,000 for the two classes) • Fees can be used for these classes only, no competition for funding • Paid for by those who benefit

20. Results and Discussion • Detailed five-year plan was developed in Fall 2007, no funding available • Due to fees, will complete this summer • Fees can be used for these classes only, no competition for funding • Paid for by those who benefit

21. Results and Discussion, cont. • Goal is to have two sets of each experiment, Thermo-Heats goal achieved, Thermo-Fluids within the year • Number of students in each section accommodated at one time is now eight versus the previous four • The number of sections has been reduced by half • Additional equipment means fewer lost labs if something goes wrong

22. Conclusion • Assignment of dedicated instructor was essential • Long-range plan was instrumental in identifying necessary funds • Equipment fee was the final necessary ingredient, makes program cost-effective and sustainable • Courses are now a integral part of curriculum, strength rather than weakness

23. The End!