VCU Engineering researchers are working to make clean energy easier and cheaper

Lane Carasik, Ph.D., assistant professor in VCU’s Department of Mechanical and Nuclear Engineering, is developing methods to make clean energy more cost-effective. He’s motivated by a simple principle.

“The cheaper we make renewable and clean energy, the easier it is to implement it,” he said.

With $100,000 in seed funding from the Jeffress Trust Awards Program, Carasik and his Fluids in Advanced Systems and Technology (FAST) research group are designing efficient, low-cost enhancements to equipment used in solar, nuclear and geothermal energy systems. Jeffress Trust awards support high-impact, one-year projects that integrate computational and quantitative scientific methodologies across a broad range of scientific disciplines.

These energy systems use heat exchangers, which take energy from heat generation components and convert it to electricity. Heat exchangers usually comprise two working substances such as water, steam or air separated by tubes or plates.

The FAST research group is optimizing a specialty insert that can be placed inside a heat exchanger’s tubes to improve performance. To visualize the insert’s form, imagine holding a piece of metal tape in both hands and gently twisting it.

See the FAST Lab and examples of the heat transfer enhancements being designed there.

“A liquid running through a tube is relatively undisrupted by the geometry of the tube or the shape of the fluid,” Carasik said. “But this twisted tape component spins the fluid. This increases turbulence, which increases heat transfer.”

While “twisted tape” inserts are already in use in some advanced energy systems, the process of fabricating them has been limited by mechanical constraints. Typically, the inserts are placed inside a tube and tack welded at either end. But because of the metal’s limited tensile strength, these inserts can only be twisted a little before they break down and cause manufacturing defects.

3D printing, on the other hand, allows for a more complex — and effective — insert that can be used to characterize heat transfer performance.

“With additive manufacturing, you can actually print tighter, ‘twistier’ versions of them,” Carasik said. “You can also add your own intentional defects to find out how to make the heat transfer better and improve the performance of the whole system.”

Each geometric form the research group prints and tests starts with a world of calculations: thermal-hydraulics design calculations, solid geometry, material properties and more. From there, components are computer-designed, then printed in the Mechanical and Nuclear Engineering Innovation Lab. Finally, they are tested in the FAST research group’s Modular Separation Effects Testing Facility (MSEFT), a scaled testing loop that emulates the operating conditions experienced by these components.

Undergraduates — even first-year students — participate in each step of the process, alongside Carasik, postdoctoral research associate Cody Wiggins, Ph.D., and doctoral student Arturo Cabral.

“I really like getting students into research early on, Carasik said. “By the time they’re three years in, they’re working at a level I would expect from bachelor’s level engineers in industry.”

Senior Meryem Murphy was curious about undergraduate research but had never really participated. “One day, I was arguing with Arturo about something and Dr. Carasik said, ‘If you’re like this all the time, you should work for the lab.’” She took him up on it and spent her junior year working on an MSEFT redesign and running an experiment to see if 3D-prototyped concepts can be replicated with test metals.

Over the summer, Murphy interned with Atomic Alchemy, a medical radioisotope startup in Boise, Idaho. She said the position built on the hard, and soft, skills she gained in the lab.

“Sometimes in class, you’re required to collaborate,” she said. “But in research, it’s just ‘what you do’ to get it done.”

Rising sophomore Ryan McGuire is also looking forward to starting his second year in the lab. During his freshman year, McGuire helped develop a 3D printing technology to duplicate sequences of 3D-printed parts for the FAST research group. It’s called Retrospective Additive Manufacturing Sequencing — RAMS for short.

McGuire said the thrill of solving problems in the lab has made him reassess his own goals.

“When I was younger, I wanted to be [famous],” he said. “But now I no longer want to be famous. Research seems like more fun.”

Upon hearing about McGuire’s change in priorities, Carasik said, “Researchers can be famous too, and for good reason.”