Assistant Professor Joshua Gess studies the fundamental science of heat transfer and thermal management systems. Combining his knowledge of heat transfer with novel experimental methods, such as two-phase cooling using di-electric coolant and high-speed image capture, Gess, a co-principal investigator at the Enhanced Heat Transfer Laboratory, seeks to develop methods that ensure reliable and efficient thermal management solutions for cooling high-performance electronics systems. The demand for smaller electronic technology has driven the need for more robust and effective cooling systems. “Two-phase cooling is uniquely equipped to address that challenge,” he said.
Gess joined Oregon State in 2015. After earning his B.E. in mechanical engineering from Vanderbilt University in 2005, he worked as a mechanical engineer at SSOE Group, which included an engineering consulting assignment for Johns Manville. He moved on to Northrop Grumman in 2008, where he worked on mobile communication equipment for the military. His next stop was Auburn University in 2012 to pursue advanced degrees. He received his M.S. in mechanical engineering in 2012 and his Ph.D. in mechanical engineering in 2015.
To illustrate the potential impact of his work, Gess points to the enormous energy consumption and resulting heat created by the world’s massive data centers that serve “cloud” computing. “The amount of energy they use is astounding, and if we could make those systems just a little bit more efficient with better cooling systems, we could save an enormous amount of energy and put it back onto the grid,” he explained.
In one study, Gess is investigating the boiling heat transfer efficiency on the surface of electronic components that are immersed in non-conductive di-electric coolant fluid. The coolant removes heat from the surfaces as it boils. He likens the process to waves repeatedly washing onto a beach to cool the sand underneath — but which happens at 30 times per second. Using successive camera images, Gess is measuring how quickly the coolant moves back in to fill the void created by bubbles that form on the surface of electronic chips during the boiling process. “We want a system that uses as little coolant or generates as little vapor as possible. Maximizing the convective heat transfer occurring during bubble formation versus the latent energy removed by vapor generation is the key to increasing the surface’s efficiency.”
In other research, Gess visualizes how liquid coolant departs from the main flow to reach the surface of electronic components and determines the efficiency of that mechanism to quench the boiling process. “Every bit of liquid that comes out of the flow to reach the surface of what it’s meant to cool needs energy to get there,” he said. “We want to look at what kinds of surfaces optimize that process.”
He attributes his childhood interest in engineering to the movie Robocop and the TV series MacGyver. “When I asked my grandfather how I could be like MacGyver, he said ‘become and engineer,’” said Gess. He finds the reality of the work just as gratifying as he’d imagined. “It’s challenging from day to day and I never know what new things will arise. My students ask me questions about things I’ve never even thought about. Everything is so open ended, and I love that part of it.”
Gess also relishes the moments of enlightenment when his graduate students “get it,” and watching them grow with each new accomplishment. “The work is difficult, and I want to be there for them when they need me,” he said. “The decision to get a Ph.D. shouldn’t be taken lightly, but once they’re here, we should provide all the support we can to help students succeed.” To undergraduates, he emphasizes that their studies will have practical use on the job. “Sometimes, students feel they’ll never use what they’re learning, but I’ve been out there and I assure them absolutely they will draw on many of the of the principles we deal with.”
Among Gess’ longer-term goals is to establish a more robust support system for people with disabilities at Oregon State. “As a person with a disability, being able to return to school to get advanced degrees was a blessing, and I want to extend that blessing to others who may be intimidated by the thought of being on a big college campus where they worry about fitting in,” he said. “Let’s build an infrastructure so that anyone can come in and feel welcome.” Gess is working with the School of Public Health to start an adaptive sports program. “I’d like to get to the point where OSU can accommodate anyone who wants to get an advanced degree. I think adaptive sports is an excellent place to start.”