Danielle Larios,

‘25 Chemical Engineering - traditional track, Ancient Studies Minor

When did you begin your Research?

Spring 2023

Where does your Research take place?

Hennigan Lab, Department of Chemical, Biochemical and Environmental Engineering, UMBC

What is the focus of your Research?

Investigating the effects and properties of Aerosols, such as brown carbons, present in cloud water.

What are you looking forward to the most about your Research?

I look forward to working together with my fellow research assistants towards a real world, practical goal and continuing to do so throughout the next year.

What was the best part of your Research OR What was the biggest learning moment of your Research ?

If you are interested in research or internships, then be proactive! Even if nothing comes from it, you can only benefit from creating relationships with your professors and networking with potential companies.

Are you a member of any clubs/campus organizations?

Student Ambassador for CBEE, Social Coordinator for Tau Beta Pi

What are your goals after graduation?

Pursue a master's degree in environmental engineering

Learn more about Danielle Larios:

LinkedIn: https://www.linkedin.com/in/danielle-larios-6936a127b/ 

When the Wright brothers first launched their famous plane off the tall sand dunes near Kitty Hawk, North Carolina, it flew slower than a person can run. Now, military fighter jets routinely rip through the air at supersonic speeds of 1,000 miles per hour or more. Uncrewed experimental aircraft have even gone hypersonic, traveling more than five times faster than the speed of sound.

Flying at such breakneck speeds presents an array of engineering challenges, from the stresses on the materials to the struggle to control the aircraft.

“When flying above the speed of sound, the operating environment can degrade extremely quickly and there is very little time to react,” says Ankit Goel, an assistant professor of mechanical engineering at UMBC. “If a correcting control signal is not applied quickly enough, catastrophic failure is almost always guaranteed.”

Goel has been investigating better ways to control aircraft flying at hypersonic speeds, by primarily focusing on the vehicle’s engine. He recently received more than $850,000 in funding from the Office of Naval Research to further the investigations. Over the next three years he will partner with Kyle Hanquist at the University of Arizona and researchers from the Naval Air Warfare Center (NAWC) to develop improved engine control strategies and assess their performance in ground experiments conducted at the NAWC facility at China Lake, California.

Powering superfast flight

The first airplane to break the sound barrier—the Bell X-1 piloted by Chuck Yeager in 1947—was dropped from the bomb bay of a Boeing B-29 and fired rocket engines to accelerate to its top speed.

Rockets are incredibly powerful, but they also guzzle fuel. A more efficient alternative for fast flight is an air-breathing engine called a ramjet. Ramjets, which work best above the speed of sound, exploit the fast forward motion of the plane to effectively “ram” air into the engine and compress it. Squeezing the air heats it up, and the hot air then spontaneously ignites the fuel. As the burning mixture is channeled out the back of the engine, it pushes the aircraft forward.

Ramjets can burn either liquid or solid fuel. In the solid fuel version, which Goel and his collaborators are concentrating on in this latest project, sand-like grains of solid fuel are pressed together and embedded in the sides of the engine. This eliminates the need for pumps and other equipment to inject liquid fuel. It also means the fuel can more easily be transported and stored.

A solid fuel ramjet engine’s design is simple, but its operation is finicky. Structural vibrations, changes in airflow, and too much or too little heat can all cause the engine to stop working suddenly. Sometimes the engine will “buzz” in a rapid series of undesirable starts and stops, a state known as “engine unstart.”    

“More reliable control of the engine could enable faster flight, longer range, and better maneuverability,” says Goel. To get that better control, Goel and his collaborators must grapple with the complex and chaotic environment inside the engine.

A tricky controls problem

Imagine a car driving along a hilly road. If the driver wants to maintain a constant speed, they must press the gas pedal harder going up the hills. If the car has cruise control, a computer can do the work of the driver. This is an example of a relatively simple control problem.

Ankit Goel (Marlayna Demond ’11/UMBC)

The inside of a solid fuel ramjet engine presents an example of a not-so-simple control problem.

A number of factors make the problem especially difficult. For starters, conditions inside the engine are constantly and rapidly changing. As the solid fuel burns away, the shape of the combustion zone inside the engine changes, which changes the airflow, which affects the rate of burning. Conditions shift dramatically in less than one-thousandth of a second. The system is also very sensitive to slight perturbations. A small change in flow conditions upstream can lead to big changes downstream.

It’s nearly impossible to completely understand and model what is going on.

In the face of such complexity, Goel is turning to a control technique that’s relatively novel in aerospace applications: machine learning. The beauty of machine learning is that it can solve problems without needing a conceptual understanding of them. The downside is that most machine learning requires enormous datasets and large amounts of computational power to work, two resources that aerospace applications typically lack. However, Goel and his collaborators have found a potential solution.

Real-time learning for aerospace

The researchers are experimenting with a technique that can learn, quite literally, on the fly, rather than being trained ahead of time. This distinguishes the technique from typical machine learning. While the ramjet is operating, the learning algorithms will continually re-evaluate the relationship between two simple factors—a measure of the air that’s being let into the engine and the thrust that the engine is generating—and use that relationship to drive the generated thrust to a desired value. By implementing a learning-based control scheme, the technique can control the output of the engine while ignoring the complexity of what’s actually happening inside.

The researchers plan to test their model first on computer simulations of a ramjet engine, and then on the real thing.

The ultimate goal is to embed the learning controller in a system that would take pressure sensor measurements from an engine in flight and use them to rapidly adjust the airflow into the engine—perhaps making thousands of small changes a second—to control the thrust. This would mean that flight operators could count on getting the requested thrust from the engine, even if flight conditions are changing.

Goel says the proposed learning technique could also be used on systems far removed from superfast aircraft. “The key insights into what makes the technique work in highly unmodeled and uncertain systems will allow us to generalize it to a large body of interesting dynamic problems,” he says. The team is already thinking about applying it to other types of aircraft, such as vehicles that use flapping wings or that take off and land vertically.  

Parham Oveissi, a Ph.D student in mechanical engineering at UMBC who will be involved in the research, says he is motivated by a deep interest in developing control techniques for aircraft, an interest he has nurtured since childhood, when his parents gave him a toy quadcopter. “This early encounter ignited an enduring curiosity within me, driving me to unravel the mysteries of flight and explore methods of controlling these machines,” he says. 

The research project will be an exciting opportunity to develop his knowledge and skills. “I’m excited to collaborate with professionals, gain valuable research experience, and see the impact of my contributions,” he says.

The success of the project will hinge on the joint efforts of researchers with a variety of skill sets, from a variety of institutions.

“This work requires an interdisciplinary team,” says Kyle Hanquist, an assistant professor in the Department of Aerospace and Mechanical Engineering at the University of Arizona who will contribute his expertise in reactive flow modeling to the project. “We are working together to tackle a difficult problem that none of us could tackle on our own.”

Michelle Starz-Gaiano, professor of biological sciences, joined the UMBC faculty as an assistant professor in 2008, fresh from a postdoctoral fellowship at Johns Hopkins University. Since then, her research program has blossomed, she’s mentored half a dozen graduate students and more than 50 undergraduates, and she’s taken on numerous leadership roles. In 2014, she received the Donald Creighton Outstanding Faculty Member Award from the UMBC Graduate Student Association for her excellent mentorship. 

This August, she’ll bring all of that experience to a new role: department chair. As department chair, Starz-Gaiano will be responsible for leading the department into a new era at UMBC, as well as managing day-to-day tasks from teaching assignments to faculty meetings. The role requires managerial skills as well as a deep understanding of the department and its needs.

“I think it’s an important time to step into the job,” Starz-Gaiano says, given setbacks like restricted lab access during the COVID-19 pandemic and recent flood damage in the Biological Sciences Building. “This gives us an opportunity to reevaluate what is working well and what we can improve on or change to make the department grow stronger. I think we have amazing people working and studying here, and I really want to make sure they can be successful.”

Starz-Gaiano has grown up as an independent researcher within the department. “That means that I know inside out what works well in the department and what we can do better,” she says.

A supportive environment

Starz-Gaiano didn’t come to UMBC expecting to be department chair one day, however. In fact, when she started her undergraduate career as a first-generation college student, she didn’t even know what a professor did. But with supportive mentors and colleagues—the same kind of support she now offers to others—she found her way.

The opportunity to do many different things as a faculty member was a good fit, Starz-Gaiano says, and UMBC, in particular, attracted her with its reputation for innovation. “It’s really cool to be in a place where we’re building new things and not entrenched in historical perspectives,” she says.

That innovation includes opportunities at UMBC for faculty to receive mentorship and gain important skills beyond their research discipline, such as in teaching, leadership, and management. Starz-Gaiano has taken advantage of many such opportunities. The College of Natural and Mathematical Sciences (CNMS) Entrepreneurial Skills Training program, a week of sessions led by Gib Mason ’95, economics; the Teacher Scholar Program from UMBC’s Faculty Development Center; and UMBC’s Women in Science and Engineering group all offered resources, support, and training opportunities as Starz-Gaiano’s career progressed, preparing her to take on future opportunities. 

Paying mentorship forward

After gaining tenure, Starz-Gaiano became a mentor for the Teacher Scholar Program, and in 2015, she took on the role of graduate program director (GPD) in the biological sciences department. A GPD must do everything from support students experiencing challenges to enforce program policies and manage recruitment efforts. It requires effective mentoring of students and collaboration with colleagues. 

“I benefited a lot from having good relationships with my mentors,” Starz-Gaiano says, so now she works hard to do the same for her mentees and every graduate student she meets.“It’s challenging to be a mentor, because everybody needs something different. And working that out means it’s never perfect. But being open to that reality is part of the strategy to make mentoring work well.”

Putting students first

Amanda Monahan, Ph.D. ’15, biological sciences, says that Starz-Gaiano’s adaptability is one of her biggest strengths as a mentor. “She is able to read and conform to her trainee’s personality, needs, and comfort. I was more independent and she gave me that leeway,” Monahan says, but “some people need a little more hands-on mentorship, and she will provide that in those cases. It is rare to see the level of adaptability that Dr. Starz-Gaiano is able and willing to offer.”

Monahan continued to turn to Starz-Gaiano for guidance after graduation, especially as she transitioned from a research role to one in scientific publishing. “Even though I was no longer her student, she listened to me and provided reassurance and advice throughout the entire process,” Monahan says. “This is just who she is. She will always put her students as a top priority, even when they are no longer her active students.”

For Philip Farabaugh, professor of biological sciences and the outgoing department chair, Starz-Gaiano’s outstanding work with graduate students makes her a natural choice to succeed him. “I have come to rely on Michelle in her role as the graduate program director,” he says. “Michelle has led the graduate committee to ensure we have the best possible students in our M.S. and Ph.D. programs and provided mentorship and friendship to all. Her work in this pivotal position showed me that she had all the skills and personality traits to make her a great department leader.”

Embracing change

As chair, Starz-Gaiano says she is “excited to get to know what my colleagues are doing even more. I’m hoping to be able to energize people around each other’s work,” noting that new hybrid work patterns can make it more difficult to keep up with colleagues. “I’m hoping we can build relationships a little more in the department and maybe beyond the department. I think there’s a lot of potential.”

She also wants to take advantage of university-level transitions, such as the new president and future new provost, to advocate for the department’s needs. Farabaugh supports that vision.  

“Michelle has a clear sense of the direction the department should take to tap opportunities and meet challenges as UMBC adjusts to its new status as a Carnegie R1 institution, while making sure that we continue to provide the excellent undergraduate education and research training that UMBC is renowned for,” Farabaugh says. “I have the greatest respect for her as a colleague and am certain that she will be a terrific chair, the first woman to hold that position in our department.”

Building on strengths

While there is always room to grow, there are so many existing strengths to build on. “I think the research people are doing is exceptionally strong, and I think our department is great at meeting students where they are and helping them be successful, without taking on a sink or swim approach,” Starz-Gaiano says. “I think we have amazing teaching faculty. We have lecturers who not only do their job but do research in pedagogy and try to find best practices and then actually change their teaching based on their findings.”

To more junior faculty looking to find their footing, Starz-Gaiano says, “I think getting involved is really important, and doing the things that are of interest and important to you.” Starz-Gaiano has been doing that for 15 years at UMBC, resulting in lasting positive impact on her students and colleagues. As the new chair, there’s no sign of her stopping now. 

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