Eldredge conducts computational and theoretical investigations of fluid dynamics and regularly teaches both undergraduate and graduate courses on the subject. He directs the Simulations of Flow Physics and Acoustics Laboratory, where he has mentored nearly 30 undergraduate and graduate students. He is the author of “Mathematical Modeling of Unsteady Inviscid Flows,” which covers tools designed to help readers develop physics-based mathematical models for a variety of flows, including attached and separated flows past wings, fins and blades of various shapes undergoing arbitrary motions.

In 2024, Eldredge received a UCLA Distinguished Teaching Award in honor of his exceptional teaching skills, proven impact on student success and fostering an inclusive learning environment. He is a fellow of the American Physical Society, an associate fellow of the American Institute of Aeronautics and Astronautics, and a co-founder of the Southern California Flow Physics Symposium.

Prior to joining the UCLA Samueli faculty in 2003, Eldredge was a research associate at the University of Cambridge in the U.K. for two years. He received his doctorate in mechanical engineering from Caltech and his bachelor’s degree in the same subject from Cornell University.

“My primary objective is to do everything I can to support the amazing research and excellent teaching of our department. Both the aerospace and mechanical engineering programs have risen in the national rankings in the last few years, and our aerospace program is now in the top 10. We want to continue that upward progression.” – Jeff Eldredge

Q. What are some of the main research projects that you are focusing on this academic year?
A: I have three major research areas of interest and, while these will seem quite different from one another, they are united under the topic of “mechanics” (fluid mechanics or solid mechanics).

(1) Sensing and control in aerodynamics. When aircraft (particularly small ones, like drones) fly through atmospheric turbulence or through the wakes of other aircraft, they are bounced around a lot. Obviously, we find that annoying when we fly. It can be more problematic for small vehicles, which feel those bounces more strongly. This is only going to get worse with climate change, unfortunately. We are addressing two related questions: first, how can we use the sensors on an aircraft to detect these disturbances and estimate the full state of the airflow? And second, how can we use that information to control the flight, and particularly, smooth the aircraft’s ride? We use a combination of knowledge of aerodynamic flow physics, control theory, and, emerging tools from machine learning to address these questions. This is an exciting area that will lead to major advances in how we design and control aircraft flight.

(2) The mechanics of bacteria walls. Bacteria can pose a major human health hazard, and there is an alarming increase in strains that are resistant to antibiotics. The wall of a bacterium provides it with protection, and antibiotics interfere with this protection by, for example, preventing the wall from remaining strong while the bacterium grows. But bacteria have evolved a variety of defense mechanisms and are capable of surviving in a remarkably broad set of environments. We are interested in characterizing the bacterial wall’s mechanical behavior, and particularly, the interplay between a weakened bacterial wall and the various safety valves and other features that a bacterium uses to heal and survive. We think this interplay has a significant role in drug resistance. With our collaborators, who conduct awesome experiments by pushing on live bacteria, we develop computational models for the response of bacteria. The understanding that comes from these investigations will hopefully help us design better antibiotics.

(3) Design of high-performance thermal management devices. A wide variety of applications in electronics require cooling of heat sources, for example, in consumer electronics and satellites. We are interested in one particular device for this purpose, called an oscillating (or pulsating) heat pipe. This device relies on a complex but elegant combination of phase change (between liquid and vapor) and fluid dynamics inside of a tiny serpentine tube embedded into a thin plate, and it can bring about significant increases in thermal conductance. One of the reasons that they have not yet become more popular is that they have notable performance limitations that are hard to predict. In collaboration with other MAE faculty, we have been using our deep knowledge of flow and thermal physics to reveal the fundamental origins of the performance limitations of these devices. By understanding these, we are understanding how to design in a manner that they can be avoided.

Q. How do you work with undergraduate and graduate students on these research projects?
A: I have a relatively small research group, with both graduate and undergraduate students who are deeply involved in researching the topics I mentioned. Many of my undergraduate students have started in my group as second-year students, and they invest several years on their topics before they finish their degrees. I want each student to have complete ownership of their project, so that their success is unambiguously their own. That’s not to say that they are all working in isolation: there is cross-fertilization and mentoring among the students, and I give them frequent opportunities to present to the group or in conferences.

Q. How will your research be translated into new technologies?
A: My research group concentrates primarily on the fundamental underpinnings of our projects, so we are not directly focused on translating the work into new technology. But that eye toward technological advancement motivates all of our work. For example, we seek practical solutions to aerodynamic flow sensing and control that could be integrated into novel aircraft designs. As weather events become more energetically charged with climate change, some of the basic tenets of aircraft design will need to be rethought so that both crewed and uncrewed vehicles can remain performative and safe.

In bacterial mechanics, we are guided by the overarching challenge of antibiotic resistance, and we believe, rather strongly, that new antibiotics must be designed to contend with (or overcome) the survival mechanisms of bacteria. It’s remarkable how little we know about these mechanisms.

Q. How could private funding through donor gifts enable you to further your research at UCLA?
A: Much of our work on the recent projects has been funded by the National Science Foundation (NSF), a decadeslong partner in supporting basic science and engineering in this country. Even in the best of times, NSF grants have not grown to match the cost of doing research and now barely support one graduate research student. As such, private support plays an increasingly vital role in advancing our research projects. To make progress on discovering solutions for real-world problems and developing new technologies — particularly those that are still several years away from commercialization — we need continuous philanthropic investment in our work.

Q. As the newly appointed chair of the Mechanical and Aerospace Engineering Department, could you discuss your key priorities and goals for the department moving forward?
A: I have a number of objectives as chair of the MAE Department. My primary objective is to do everything I can to support the amazing research and excellent teaching of our department. Both the aerospace and mechanical engineering programs have risen in the national rankings in the last few years, and our aerospace program is now in the top 10. We want to continue that upward progression. That is a product of hiring great faculty, supporting the development of their labs, and facilitating them to bring in the best students and researchers. We are a public university, so sometimes we have to be a bit resourceful. We have a great dean, and I feel very optimistic about the future.

Q: As fluid dynamics continues to intersect with fields like energy and healthcare, where do you see the greatest potential for collaboration to address real world challenges?
A: Fluids (air, water, oil, blood) are everywhere! So fluid dynamics is a part of virtually every real-world engineering problem we encounter. We have always partnered well with other fields to address these problems. Fluids have a number of complex phenomena — shock waves, phase change, reactions, interaction with flexible structures — that we like to exploit, but have often challenged the conventional tools we use for control. This made fluid dynamics a natural early target for applying tools from data science and machine learning. We have now seen about a decade of that “exploratory” partnership between fluid dynamics and machine learning, and I think we’re now entering the era of seeing truly remarkable results.