January 22, 2020
Aerospace engineering graduate student Chloe Johnson was selected by Aviation Week Network and the American Institute of Aeronautics and Astronautics (AIAA) for its 20 Twenties award program for 2020. Students are nominated by their university based on not only on academic performance, but also on their ability to contribute to a broader community and to communicate the value of their research. Each year 20 highly qualified students from across the world are selected for the prestigious award.
Johnson, a second-year Ph.D. student working under the advisement of Jayant Sirohi, an associate professor in the Department of Aerospace Engineering and Engineering Mechanics, is leading cutting-edge research to test new stacked rotor (helicopter) technology for vertical take-off and landing (VTOL) aircraft that will be used in the development of future “air taxis.” The research is being funded by Uber Elevate and is partnering with the U.S. Army Research Labs (ARL).
Stacked rotors are a novel technology that allow for the thrust of the vehicle to be controlled by changing rotor geometry mid-flight, which Johnson said has never before been implemented during flight.
Johnson and the research team have already conducted experiments with at least 30 different configurations and still have more testing to do, including measuring noise and adding a second motor to control each rotor individually. They expect to provide recommendations to Uber Elevate based on their experimental results after the project is completed this spring. All data is being made open to the public to increase public awareness of the development of these new air taxis.
“The main goal is to determine configurations where there are significant changes in thrust and lowest noise,” Johnson said. “Noise is determined by measuring sound pressure levels with the microphones and thrust is measured with load cells attached to the rotors.”
Johnson said she is inspired by her work for many reasons, including the fact that it is experimental and novel, as well as the impact it will make on the development of Urban Air Mobility.
“This work is important because VTOL aircraft will soon affect everyone: passengers, pilots, and local residents,” Johnson said. “Through our research, we can ensure that these new vehicles will not only be safe, but quiet and efficient.”
Johnson has presented her research at technical conferences and has shared her work with local middle school and high school students. She is especially passionate about encouraging more women to pursue aerospace engineering and careers in STEM.
“A large focus for me has been to encourage women to become interested in STEM at a young age and to cultivate a positive environment for women in aerospace engineering,” Johnson said.
Once she completes her graduate studies at UT Austin, Johnson said she hopes to stay in academia working as a professor or continuing similar work at a research institution.
