Dr. Hargather’s Gas and Shock Dynamics Laboratory
Next to the main EMRTC building sits the Shock and Gas Dynamics Lab, led by Dr. Michael Hargather. He is a professor of Mechanical Engineering who has been at Tech since January of 2012, and he brings a background in fluid dynamics and optical diagnostics to his current research. I sat down with him in his office to learn about his background and research.
Michael Hargather hails from upstate New York and did his undergraduate, graduate, and post-doc work in mechanical engineering at Penn State University. From the beginning of his college career he knew he wanted to be a college professor and do research. In graduate school he worked for Gary Settles, a world expert at refractive imaging techniques. During this period, Hargather gained experience in a variety of areas, working with explosive detection, sub and supersonic wind tunnels, and explosive effects on materials. He particularly focused on deformation of surfaces due to explosions. This work revolved around different types of imaging, some of which he still uses in research here at Tech. Speaking of his graduate work, he says, “the common thread through all of it really was optical diagnostics and basic fluid dynamics.” His primary research interest is characterizing fluid flows at any scale, and he has found his niche in explosives. He had learned of EMRTC while he was at Penn State, so when he saw the job posting at Tech he was excited and knew it was a great opportunity.
Research at Tech
Dr. Hargather explains the focus of the Shock and Gas dynamics laboratory: “A lot of what we do is tracking shocks…How do gases and how do shock waves get produced and how do they move and how do they interact dynamically in different scenarios?” Most of the lab’s work today is complex interactions, studying how shock waves reflect from surfaces and interact with themselves to form things like mach stems. Also, the lab studies how shock waves interact with the surrounding environment and the gases that are produced by the explosion.
The lab currently has several projects looking at characterizing shock propagation. The goal is to understand how the shock propagates, how the gas cloud propagates, and how the gas cloud evolves in a turbulent nature. These things are studied at multiple different scales: the group does everything from table top explosions to field scale work on EMRTC property. Additionally, the lab measures velocities in flows—shock velocities, gas velocities, and velocities of fragments and projectiles that may be imbedded in the flow. For example, how will the outer casing of an energetic material be accelerated outward in an explosion, and what are the velocities of the fragments? To better understand the fragmentation behavior they are partnering with Dr. Jamie Kimberly, who works on understanding the phenomenon from a solid mechanics perspective.
Lithium ion battery failures are another area of interest in the Gas and Shock Dynamics lab. Do batteries explode under particular loading scenarios? “It turns out they don’t explode; they’re all built with vents so they spew gases out, so now we’re looking at studying that gas propagation,” Hargather says. All of the work the lab does is centered around high speed imaging and making measurements in tough environments—such as the areas near explosions and batteries spewing corrosive materials.
The Joys of Being a Professor
Dr. Hargather likes all aspects of his job: traveling, doing research, and especially teaching. He describes a time when he was a post-doc and didn’t get to teach for a semester—“I was miserable…I draw a lot of my energy from the classroom, from working with students.” Working in the defense industry is fulfilling, he says, because his work makes an impact on our country. He also loves the flexibility of his job as a professor: “A nine to five job would kill me.” Being a professor is great, he says, because you get to help students go down different paths and get their dream jobs. “That’s really exciting…there’s a lot of satisfaction in doing that.”
I asked Dr. Hargather for his advice for students, and he said, “Do what excites you, and there’s more than one path that will lead you where you want to get to.” If you’re sick of being a mechanical engineer and you like biology, go be a biologist, Hargather says. “I think for students today it’s important to explore what excites you and to have fun with what you’re doing”