Sibley undergrads working to develop a method of achieving "flow awareness" with an autonomous flight vehicle

Autonomous Vehicle

By Erin Philipson

Marigot Fackenthal ’21 and Grace Ding ’21 are working with Dr. Gregory Bewley, assistant professor in the Sibley School of Mechanical and Aerospace Engineering, to develop a method of achieving “flow awareness” with an autonomous flight vehicle. As other researchers have shown, flow awareness can be useful in optimizing a vehicle’s control algorithm. 

Wind Tunnel in the Bewley Applied Turbulence Lab
Wind Tunnel in the Bewley Applied Turbulence Lab

The set-up is simple – the researchers start with a small, off-the-shelf quadcopter that is instructed to hold its vertical position in a wind tunnel. Upstream of the quadcopter is a horizontal cylinder, which sheds a Kármán vortex street, a repeating pattern of swirling vortices with a characteristic frequency. The vortex street inflicts a regular disturbance on the quadcopter, which causes the quadcopter to bob up and down. 

Fackenthal and Ding’s research has gone through several iterations – most recently, they are interested in showing that frequency analysis of the quadcopter’s power consumption over time can reveal critical information about the flow.

“The power consumption data has very prominent peaks that correspond with the ambient vortex shedding frequency – this tells us that analyzing power consumption in the frequency domain can be a simple and effective method of achieving flow awareness,” says Fackenthal.

The system is complex with lots of potential for a messy, undecipherable signal – however, Fackenthal and Ding observed the vortex shedding frequency clearly in the power consumption data.

Marigot Fackenthal in Wind Tunnel
Marigot Fackenthal '21 in Wind Tunnel

“This is an appealing method of flow analysis, as it can be performed mid-flight and without the use of complicated sensors, computationally heavy math, or nearby stationary references,” says Fackenthal.

Fackenthal and Ding have benefited greatly from Bewley’s mentorship. He has challenged them to think critically about their experiment and helped them develop an intuitive understanding of the complex dynamics involved.

“He’s given us quite a bit of autonomy, even trusting us with a multi-year project that uses our school’s largest wind tunnel. We always feel very lucky to have been granted such trust, especially as undergraduate students,” says Fackenthal.

The graduate students in Bewley’s lab have also provided a supportive environment for Fackenthal and Ding to conduct their research.

“The graduate students in our lab have added greatly to this mentorship as well - they have always been supportive of our efforts (even through the tough beginning stages), and have always made us feel comfortable in the lab,” says Ding.

Both Ding and Fackenthal lead busy lives outside the Sibley School. Ding is a volunteer firefighter with the Cayuga Heights Fire Department and is a Midshipman at the Cornell Navy Reserve Officer Training Corps (NROTC) unit. Fackenthal has been captain of the Cornell Women’s Varsity Fencing team since she was a sophomore.

Ding will be staying at Cornell for an extra semester after graduation to complete her Master of Engineering in Mechanical Engineering, after which she will be commissioned as a naval officer.

After graduation in May, Fackenthal will be starting a role at SpaceX as a build engineer for Starship’s propulsion team.

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