1. Renovating An Ancient Low Speed Wind Tunnel
Narayanan Komerath and the Experimental Aerodynamics and Concepts Group Daniel Guggenheim School of Aerospace Engineering Georgia Institute of Technology, Atlanta

2. Acknowledgements
 This paper, and the EXTROVERT system that enabled it, were developed using resources provided under the NASA Innovations in Aerospace Instruction initiative, under NASA Grant NNX09AF67G, monitored by Mr. Tony Springer. The assistance of the students in the Experimental Aerodynamics and Concepts Group is gratefully acknowledged.

3. John J. Harper Wind Tunnel
mph; Closed return; Ambient pressure test section, Floor turntable, 7’ x 9’; <0.3% turbulence
Pressure scanning; Hot film anemometry; 30Hz. Dual Nd-YAG PIV, Stereo & Tomographic PIV.
6-DOF load cells; LabView signal analysis; 16-channel A/D; DSP/DIP.
The School of Aerospace Engineering was established in 1930 around the 9-foot Low Speed Wind Tunnel pictured above. Today the tunnel is called the John J. Harper wind tunnel. Other facilities in Experimental Aerodynamics include the 42” open-return AeroControls wind tunnel, and a 9-foot rotor Static Thrust facility.
Laser-based diagnostic techniques are a strong component of today’s Experimental Aerodynamics, but we also get involved in a variety of diagnostics development and aerodynamics problems

4. The paper describes how a team of aerospace engineering students planned, organized, implemented and recorded a fast-paced project in support of the repair and renovation of a very old, major university low speed wind tunnel.
1960-vintage water-cooled clutch failed on Nov 1,
Project ~ April 2012 to replace the clutch and the 600 hp motor with a modern variable frequency drive and motor.

5. Problem Statement
Use shutdown period to reorganize inventory.
Experiments & analysis to specify new motor and braking.
Pressure washing, turning-vane repair, diffuser painting.
Tunnel feedback control system & control panel.
Honeycomb repair and tunnel calibration.
1 summer to do it all.

6. Technical Problem Statement
Safety, safety, safety!
Unknowns in dealing with 80-year-old components.
Needed skills had to be learned.
Cell-phone compatible Inventory Organization.
Finding the inertia of an inoperable fan/shaft system.
Tunnel control system and control panel development.
Predicting performance to specify emergency braking.
Calibrating open tunnel motor performance.
Repairing honeycomb in the settling chamber.
Calibrating the turbulence in the test section.
Planning a new fan system.

7. Educational Problem Statement
Needed skills had to be learned on the job.
 AE students from freshman to PhD.
Technical content outside AE curriculum.
Where and how do we find the required knowledge?
How do we ensure correctness of use of the knowledge?
How do students communicate within and across task teams?
How are project timelines met, with a diverse team of students?

8. Team organization
Communications & Archiving:
Project Document
Whiteboard Walls
Countdown List
Facebook
LaTEX
Meetings

9. Issues, Knowledge Needs, and Sources
Knowledge area
Sources
Fan inertia
Dynamics
Courses, innovation.
Tunnel power requirement; Braking profile
Fluid & thermodynamics; fan aerodynamics, electric machines.
Books, papers on closed circuit tunnel loss; calculations, EE textbooks.
Pressure washing
Sizing equipment and procedures, drainage rigging.
Retail outlets, equipment specs
Inventory organization
Smartphone apps, QR code system
Friends in ECE/ computing, cellphone ads, web
Painting options; Safety issues; Vane repair options
Chemical safety, application difficulties, surface nature, cost, color selection. protection, sealing and removal. Metal vs. wood vs. Bondo /fiberglass. Safety, equipment, training.
RTK certification & Research ethics courses, MSDS, discussion experts, paint manufacturer sites; equipment specs, discussions with experts & team, textbooks, safety manuals, practice. Composite blade making experience
Sensors & data acquisition
Pressure, temperature, velocity, torque, strain. signal processing.
Our group, vertical transfer.
Feedback control system
System dynamics, control systems, dynamics.
AE courses, textbooks, discussions

10. Images from Summer 2012 Installed! Old motor gone, new arrival
How will the diffuser look with a paint job?
After
Vanes Before

11. Methods Used Extensive use of paste-on whiteboards
Video-based MI measurement
Safety eqpt.
Smartphone
Inventory
Controls
Development

12. Level of detail needed in the Project Document
Movie frame from experiment to measure fan/gear/shaft inertia

13. First Run After Repairs!

14. Lessons
Case study of a project done to an exacting timeline and success metric. Students with diverse experience.
Countdown list with deadline and contingencies.
Students learned LaTEX quickly - team-authored project document.
Skills with cellphone apps - a smart-phone/ QR-code inventory system.
Engage least experienced team members, ask them to delegate tasks and track timelines.
Paste-on whiteboards for communication and technical thinking.
Huge, proven improvement in the effectiveness and depth with which our students are able to pose and solve problems that cut across disciplines.