If you hear a series of loud, percussive noises emanating from the Oregon State University campus, don’t worry — it’s just researchers blowing things up for science.
The metallic bangs — similar to the sound of a good-sized firecracker tossed into a trash can — are coming from the Aero Lab, a small building on Southwest 30th Street between Western Boulevard and Washington Way, where a small team of scientists have been setting off a series of controlled explosions for about seven months now.
“We have a project looking at detonations,” said David Blunck, an assistant professor of mechanical engineering. “A detonation is a flame that goes supersonic — about 1 mile per second is how fast it burns.”
To study the detonations, Blunck and his team — which includes fellow faculty members Kyle Niemeyer and Sourabh Apte and three grad students — use a device called a pulse detonation engine. Basically, it’s a 6-foot length of 3-inch steel pipe with a system of tubes for supplying fuel, a spark plug to set it off, and sensors to measure and record what happens when the combustible gases blow up inside the pipe.
The whole process is controlled and monitored from a computer a safe distance away, in another room on the other side of the building.
For now, the researchers are gathering data to characterize the properties of the explosions. But the ultimate goal is to apply that knowledge in a practical arena.
“The research we’re doing is to increase the efficiency of coal-fired power plants,” said Derek Bean, a grad student working toward a master’s degree in mechanical engineering.
The work is part of a 2½-year project funded by a $675,000 grant from the U.S. Department of Energy, with $200,000 in additional support from OSU and the Oregon Built Environment and Sustainable Technologies Center.
Based on the data they gather, Blunck’s group will perform calculations that will be passed on to researchers at the Albany Research Center, a branch of DOE’s National Energy Technology Laboratory, who will look at ways to use detonation rather than less intense forms of combustion to maximize the amount of energy produced by a given amount of fuel.
“This applies to other (types of) power plants as well,” Blunck said. “It’s not just for coal.”
And there may be other useful applications for the research as well.
“These kinds of detonations are also of interest to the Air Force,” Blunck said. “We’re working with them on a propulsion project.”
In the quest for data points, the researchers have been giving their pulse detonation engine a pretty good workout, firing it 50-100 times a day, three days a week — and every time it fires, it makes noise. Bean said the first detonation of the day still makes him flinch, even though he knows it’s coming.
“You can feel it through the wall,” he said. “You can feel it through your feet.”
Of course, the neighbors can hear it as well. The nearest houses are a block or two away, but the noise definitely carries.
The researchers have taken a number of steps to minimize the impact on the neighborhood, including scheduling the work to happen only during daylight hours and installing a ventilation system so the shop doors can be kept closed during detonations. (They even tried building a silencer for the detonation engine, but that didn’t work out.)
“We try to be sensitive to people,” Blunck said.
According to Scott Haberkorn, who oversees the Benton County emergency dispatch center, there have been few if any calls to 911 operators about explosions on campus.
Nevertheless, the noises have created a bit of a mystery for neighborhood residents.
Larry Passmore, who lives a few blocks away on Southwest 35th Street, said he’s wondered for months about the unexplained sounds coming from the direction of Reser Stadium.
“It sounds like something halfway between an explosion and a pneumatic (device),” he said. “Like a big piece of machinery is pounding the earth.”
The noises only happen during the daytime, he said, and even though he can hear them inside his house, Passmore said, they’re not really loud enough to be considered a nuisance.
He said the noises remind him of the days when the stadium crew used to fire blank rounds from a small cannon when the Beavers scored a touchdown at home football games.
“But that was louder,” Passmore added.