Engineering building houses a wind tunnel
Tunnel can reach speeds of up to 120 miles per hour, used for three engineering classes
September 25, 2013, 8:22 pm · Updated September 25, 2013, 11:21 pm·
Sandra Loza-Avalos | DP
The Towne building has a secret padlocked in the basement..
Room B2 has long housed Penn’s only wind tunnel. A little known fact to most Penn students including engineering students, the wind tunnel has helped many in designing projects and gathering data.
Though small compared to industry standards, the wind tunnel is quite imposing by normal standards. Painted a pale blue, the Aerolab Educational Wind Tunnel System measures 15 feet long and 6 feet high and takes up most of the underground room in Towne. Bruce Kothmann, a senior lecturer in the Engineering department, estimates that it is around 15 years old.
The Mechanical Engineering and Applied Mechanics Department is one of the only departments to use the wind tunnel. It is used by three classes, among them Junior Design Lab I and II and “Introduction to Flight.”
Junior Design Lab I is currently using the wind tunnel to test the efficiency of student-designed wind turbines. Students first research and create a small scale model of a wind turbine, which they then place inside the chamber of the wind tunnel to test how much electricity their turbines generate. According to Kothman, the wind tunnel can reach speeds of up to 120 miles per hour, although for educational purposes, 60 miles per hour is usually sufficient.
Engineering junior Audrey Keller, who is about to start building her own turbine, said, “I’m excited … everyone in MEAM knows about this project. It’s pretty famous.”
After testing the model turbines, students create full-size prototypes eight to ten times the size of the model. The wind tunnel cannot be used to test the prototypes, which are too large to fit inside the tunnel. Instead, prototypes are fitted to wheeled carts which sprinting students then push down the long hallways of Towne in order to simulate wind.
In Junior Design Lab II, the wind tunnel is used to measure convection, “the transfer of heat by moving air,” by seeing the time it takes a piece of hot metal to cool to a specific temperature at a controlled wind speed. This helps students understand the principles behind such applications as varied as laptops and jet engines.
The wind tunnel is also used in “Introduction to Flight” to “measure the thrust and torque on a small propeller, and once again use ‘scaling laws’ to predict what will happen with a larger propeller.”
When asked whether Penn will ever invest in a full-size wind tunnel, Kothmann replied that the ones similar to what Boeing has are “not cost-effective.” He also argues that being forced to “use data they gather from testing a small turbine in the wind tunnel to predict the behavior of a large turbine operating in the real world” is a valuable learning experience.
Dean Wilhelmi, an Engineering senior, said moving from the small model to the large turbine is “a little challenging in terms of just understanding the dimensional analysis,” but he, like Kothmann, did not see a need for a full-size wind tunnel.
Still, Kothmann admits that, “It’s hard to get good data on a really small model.”
Although his students joked about the diminutive size of the wind tunnel during class, Kothmann points out that it is educational as well as cost-effective. “We have a fairly small engineering department, so the fact that we have a wind tunnel at all is very good.”