SoE professors’ research projects target new discoveries for space and Earth
Whether looking to gain a deeper understanding of combustion to conserve energy or looking to nourish plant roots with electrostatic spray, recent research efforts of mechanical and aerospace engineering professors Stephen Tse and Jonathan Singer aim to impact life in space – and on Earth.
Conducting “Flames in Space” Experiments from Planet Earth
Well before the coronavirus pandemic struck and largely shuttered the Rutgers campus, Stephen Tse, professor and director of outreach in the School of Engineering’s Department of Mechanical and Aerospace Engineering, began conducting a series of remote International Space Station (ISS) experiments from his Rutgers office that have the potential to help diminish fuel usage and pollution by improving combustion efficiency.
Post-pandemic, the tests have been run off-campus. “We were fortunate that the experiments were remote and we were able to get secure connections to stream live ISS video at our homes, so the pandemic minimally affected our work,” Tse says. “It felt good to be productive during these ‘upside down’ days.”
Tse recently concluded the second – and tentatively final – round of automated tests for his s-Flame project, which aims to ameliorate energy conversion efficiency, pollutant mitigation, and fire safety on Earth and in space through a more fundamental understanding of combustion dynamics using spherical flames generated by gaseous fuels.
According to Tse, since space station experiments are subject to micro levels of gravity, flames are not subject to the buoyancy they have on Earth. This means that some flames become spherical, rather than tear-drop-shaped like candle flames on Earth, depending on the conditions. “Removing the effects of buoyancy allow us to investigate basic chemical and transport aspects, along with interesting flame responses, such as instabilities,” Tse explains.
Working with Princeton University partner and professor, C.K. Law, and SoE graduate student Jonathan Shi, the first round of NASA-approved experiments was guided in real time, where parameters could be changed on the fly, from Tse’s Rutgers office throughout the fall 2019 semester.
Round 2, which replaced nitrogen with helium as the inert in the oxidizing environment, began in February 2020. According to Tse, some results from both test rounds have diverged from initial expectations, e.g., reduction of soot formation, as well as shifts in ignition and extinction limits. “All of the experiments were valuable, as they have divulged new phenomena, in addition to helping to confirm certain chemical-physical processes or to allow new models, e.g., for radiative transport, to be developed,” he explains.
“We still have a lot of analyses to do. There is a tremendous amount of data that needs to be processed in the 250+ cases that we ran in the two rounds of testing,” he says. “Since the study was of a fundamental nature, the understanding of key mechanisms will help to optimize many combustion processes on Earth.”
Of significance to Tse was the enthusiastic response by the public to NASA Twitter and Instagram posts of videos of the flame experiments, which respectively garnered more than 80,000 and 245,000 views. “It reminded me of how important it is for those of us in the academic community to advocate for our work to the general public in an engaging way,” says Tse. “If such work gets people, and especially kids, excited about and involved in STEM, then our country’s future will be very bright.”
Helping to Improve Crop Habitats in Space
According to NASA, the ability to cultivate in-flight crop plants is essential to the support of its goals for sustained exploration of the Moon and beyond. NASA has selected Singer, a recipient of the 2019-2020 Provost’s Award for Faculty Excellence, to lead one of five research teams charged with developing new systems for growing crop plants in space. Approximately $1.2 million in funding through cooperative agreements supported by NASA AES Habitation Systems supports the projects.
Singer’s team, which includes Co-PIs from Rutgers Department of Environmental Sciences extension specialist and Department of Environmental Engineering professor A.J. Both and Rutgers EcoComplex assistant director David Specca, as well as SoE graduate students Bryan Llumiquinga and Michael Grzenda , is exploring “Staticaponics: Targeted electrostatic deposition of water and nutrients on plant roots” in his lab.
Electrostatic spray, according to Singer, is widely used in everything from commercial agriculture to disperse pesticides and for painting cars. “For this deposition, you’d take a slowly flowing liquid and electrify it, so that liquid is pulled to the target in small and even nanoscale drops,” he explains. “We’re proposing needles that spray all the time to constantly supply a steady amount of water to the roots of plants such as lettuce and tomatoes.”
The benefit of this approach would eliminate as much waste of water as possible. “Because the water would always go to the roots of the plant, you could end up using less water,” Singer posits. “More important, the users in space would be able to set the exact amount of water – and whatever nutrients – that each plant receives through its own needle.”
NASA is especially concerned with using renewable energy and minimal resources to keep people alive in a hostile environment. “These are all lessons that can help us face challenges such as climate change and resource conservation that we can take back to Earth,” says Singer. “I’m happy to be a part of research that will benefit both space exploration and also address challenges here on Earth.”