A ludicrous amount of McDonald’s straws and a whole lot of work.
That’s what it took to build the Cal Poly wind tunnel.
The university’s low-speed wind tunnel, managed by the aerospace engineering department, has come a long way since students used plastic drink straws to craft the original filter. It’s now undergoing some significant changes that will allow it to test vehicles on a moving track and use lasers for measuring instead of probes.
Jan Bernard, an aerospace senior and Engineering Ambassador at Cal Poly, loves telling tour groups the story of how students created a DIY filter for the wind tunnel back in the ‘80s.
“When they were first building it [the wind tunnel], they went and stole straws from McDonald’s for a few months. They had to filter the front of the wind tunnel with just straws and it took like 300,000 McDonald’s straws. And now they have a nice new mesh filter and everything,” Bernard said.
The filter normalizes the wind flow of the tunnel.
The large machine, which is now located in building 41B, is used for testing the aerodynamics of scaled-down models of planes, ground vehicles and other projects.
Save the tunnel
Graham Doig is an aerospace engineering assistant professor at Cal Poly who manages all aspects of the school’s wind tunnel. From renovations to AERO labs to student employees, Doig is the go-to guy.
“We really like this piece of infrastructure, and we’ve been going through a process to modernize it and upgrade the instrumentation to make sure that it’s got another 30 years of life left in it,” Doig said.
Video by Angela Fauson
Until recently, the engineering department only used the wind tunnel one quarter a year for one aeronautics concentration class in aerodynamics. With only approximately 30 students a year benefitting from the machine, Dr. Doig said funding was low and the department considered getting rid of it.
This is when Doig stepped in.
Since being hired a year and a half ago, Doig has changed the way administration and students view the wind tunnel. Now, not only are aerospace students involved with it, but also mechanical engineers, students involved with Formula SAE projects and even underclassmen who have never taken a class in aerodynamics but are interested in learning.
“In this lab, our doors are kind of open to anybody who wants to come in and work with it,” Doig said.
This includes Mustang News reporters.
Video by Suha Saya
Time for a face-lift
With big-name companies like All American Racers and Futura Industries currently sponsoring the renovations, the tunnel is moving closer to Doig’s goal of being able to test moving ground vehicles. Though not much of the outside of the tunnel is changing, “the brain of the tunnel has changed quite a lot,” Doig said.
The tunnel now has a much more modern approach to testing including laser systems instead of probes for measuring, and a rolling road for automotive testing. So far, Doig says approximately $100,000 have been put towards renovations, but there is still a lot left to do.
Students like Andrew Furmidge, a junior mechanical engineer and lead designer on the project, are responsible for these major changes. Furmidge’s time working at the wind tunnel averages at around 30 hours a week—10 more weekly hours than he is allowed to enter on his timesheet for Cal Poly.
“It’s like a second home, basically,” Furmidge said, “I’m here more than I am at home.”
The time and effort put forth by Furmidge and his team has prepared the tunnel for working with paying clients. Because each individual test requires so much preparation, however, they have had to decline many of the requests so far. The renovations are helping to expand the opportunities, though.
Even with renovations, complications and roadblocks still arise.
“If it doesn’t work out perfectly the first time, you just figure out a way,” Furmidge said, “Then we end up usually making it better the second time because we’ve learned what does and doesn’t work. It’s just the Cal Poly way of doing things. You learn by doing then you end up with a better product in the end.”
Though student employees in the wind tunnel have a lot of decision-making power on the project, there is one thing that cannot be flexible — safety precautions.
Built with strong fans that send air through a tube at speeds up to 130 miles per hour, wind tunnels can be very dangerous. If objects inside the tunnel aren’t secure, they run the risk of coming loose and getting pushed into the powerful fan blades.
Graphic by Celina Oseguera
Because of this, there are strict safety requirements in place, such as wearing goggles while in the area and always having more than one person present while operating the tunnel.
“You always have someone ready to hit the emergency button to stop it at any time if something goes wrong,” said Peter Szendreyni, an aerospace engineering senior with a concentration in aeronautics.
According to Szendrenyi, the wind tunnel is now a required part of his concentration’s curriculum with AERO 306 and 307. This means every student in the aeronautics concentration — around 30 students per graduating class—are required to have experience in the tunnel.
Bernard says today, with all the changes, the wind tunnel is one of the entire engineering department’s most glamorous pieces of equipment.
That’s quite an upgrade in status for a machine that once had a filter made of straws.