UD engineering students develop zero-gravity turbulence experiment bound for the ISS

The International Space Station isn’t just for astronauts exploring the great beyond. It also offers an opportunity for scientists of all ages and disciplines to test the limits of their research, if they’re able to propose a project worthy of the 200-plus-mile trek into space.

A small team of researchers from the University of Delaware’s College of Engineering, largely students, will soon be among the lucky few to send their own ideas to the ISS to further their research on how particles move in turbulence.

“I’ve always been interested in space, so it’s really cool to come onto a project that will hopefully be going to the ISS,” said lead student researcher Valerie Moore, a senior studying mechanical engineering.

UD is one of five universities selected to receive $100,000 in grant funding through the National Aeronautics and Space Administration’s (NASA) Established Program to Stimulate Competitive Research (EPSCoR) for an experiment to be conducted on the ISS.

“Each of these projects has the potential to contribute to critical innovations in human spaceflight on the International Space Station and beyond,” NASA EPSCoR Project Manager Jeppie Compton said in a press release. “We’re very impressed with the ideas put forward in these investigation concepts and look forward to seeing how these technologies perform.”

Evan Battaglia, a recent electrical engineering graduate, solders critical motor components and control systems to autonomously drive the von Karman flow facility, named in part for the aerospace engineer Theodore Von Kármán, who used math to study fluid flow.

Since Spring 2022, several undergraduate engineering students, led by Department of Mechanical Engineering Assistant Professor Tyler Van Buren, spent months designing a device that will fit within a “CubeSat” that will be sent to the ISS, where it will collect information about how turbulence affects particles in a zero-gravity environment. A cubesat is a small (100-by-100-by-300 millimeters), rectangular compartment that holds experiments like theirs — like a suitcase of science headed for space.

“Things on Earth that want to sink or rise really fast, in space, they’ll stay put,” Van Buren said, adding that their experiment will require no intervention or assistance from astronauts. “The goal is it would go up, plug in, run un-crewed and we’d get status updates.”

The datasets they’re hoping to collect with their small “zero-gravity turbulent flow facility” are impossible to get on Earth, but are necessary to confirm Earth-based simulations exploring turbulence in fluid mechanics.

Think about swimming somewhere shallow, close to the bottom of the waterway, and how the kicks of a flipper — or in the case of a fish, fins — kick up particles. Researchers would like to know how particle sizes interact or suspend.

“This kind of fills that gap where we start to understand how particles impact the fluid flow without worrying about the gravity being involved,” Van Buren said.

The rotor for the zero-gravity turbulent flow facility prints on a Prusa 3D printer.

Basically, explained Moore, their device is made of two cubes, each with a cylinder cut out of the center. The ends can spin in opposite directions to create the flow the researchers need, and eventually they will put liquid, bubbles and both heavy and light sediment inside. They’re utilizing something known in mechanical engineering as the Von Kármán flow, named for the aerospace engineer Theodore Von Kármán, who used math to study fluid flow and eventually helpd found the Jet Propulsion Laboratory. More informally known as the French washing machine, to create the turbulence needed to study how their materials react.

In between the two cubes is a data collection “brain,” explained Van Buren. The set-up also includes cameras that are used to record the flow.

Because the device houses water — albeit purified, deionized water, which is less conductive and safer than regular old H2O — mechanisms are needed to ensure the water stays put without human interference. Their hands-off experiment may have given them an advantage in gaining NASA’s approval for the idea, but they also have to make sure that it doesn’t break when met with the strong G-Forces that come during a rocket launch.

Joining the project team as a junior allowed Moore to learn such complex concepts that she hadn’t even encountered in her studies yet.

Recent mechanical engineering graduate Hannah Wiswell works on the zero-gravity turbulent flow facility’s fluid subsystem with a custom designed magnetic torque transmission.

“I didn’t take fluids yet, so it was really cool to go into class and already know what they’re talking about,” she said. Van Buren said the project wouldn’t exist without Moore’s work.

While Moore handles the fluid mechanics side of their work, honors electrical engineering student Evan Battaglia, who graduated in spring 2022 and is headed to Columbia University for graduate studies this fall, helped drive the programming. For the small facility to work, it needs a control system for the moving parts, for when researchers need motors to spin on lights to turn on. That will be controlled by Arduino technology. Then there’s the “brain” on the system, which is a Raspberry Pi miniaturized computer-on-a-chip (and definitely not the dessert) that allows the researchers to collect data and categorize it as needed.

These electronic devices, each with their own particular features and capabilities, will be the part of the experiment that handles instructions from operators, collects data and runs the cameras during the six months the device is in space. During that time, Van Buren said they will likely collect more than 10 terabytes of data. They’re working with NASA to determine how they’ll retrieve the data — either through transmission from space or by having a small component, such as the hard drive, sent back to Earth once the mission is completed.

In summer 2022, Van Buren and recent honors mechanical engineering graduate Hannah Wiswell were the only members of the team actively working. Over the summer, Wiswell — who dreams of becoming an astronaut herself — worked on all of the subsystems of the device, from the motors that drive the rotating flow to image processing to the particles themselves.

“I’m more of an interim editor, swooping in to help,” she said, noting that she didn’t know she’d be working on a project at UD that will someday soon go to space. “It’s crazy that you could be doing something so small that could have such a giant impact. I’m incredibly happy to be here.”

When Wiswell leaves for Princeton to pursue a doctorate in mechanical and aerospace engineering in the fall, Moore and a new team of students will step back in to take over the final year of designing the device.

As the school year gets underway, another small group of senior engineering students will be handling the thermal management, including 3-D printing the frame for their device out of flame-resistant material for their senior capstone project. Meanwhile, the team is planning an outreach effort with the Early Learning Center in Newark, where young children could learn the basics of fluid dynamics (more simply, flow, mixing and what a liquid is) and possibly even contribute a small note to be sent into space along with the experiment.

If all goes well, the device should be in working condition by the end of Summer 2023. Then it has to go through NASA’s safety testing before it can be approved for space travel. It will likely take at least another year (or more) until their device is approved to exit Earth’s atmosphere.

“Once it’s ready, then you get in line for a flight,” Van Buren said. “We could learn a lot about a very difficult problem, and this project can also just help bring eyes to fluid mechanics in general.”

Article by Maddy Lauria | Photos courtesy of Tyler Van Buren and NASA | Photo illustration by Joy Smoker | September 01, 2022

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