MAE Seminar – Cryogenic Flow Boiling Physics in Terrestrial, Partial, and Microgravity Conditions

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MAE Seminar – Cryogenic Flow Boiling Physics in Terrestrial, Partial, and Microgravity Conditions

Dear Undergraduate and Graduate Students, Faculty, and Staff,
You are invited! UF Department of Mechanical and Aerospace Engineering’s Seminar Series
This is a perfect opportunity to enjoy some coffee, cookies, and captivating talks! These sessions feature amazing guest speakers, from academic trailblazers and industry movers to our very own faculty candidates showing off their expertise and fresh perspectives.
Come for the treats, stay for the engaging discussions, and connect with fellow MAE enthusiasts. Everyone is welcome!

January 30, 2025, at 12:50pm, Location: MAE-A 303

Sunjae Kim
Ph.D. Candidate
Department of Mechanical Engineering
Purdue University

Abstract
With the growing interest in long-duration space exploration missions, cryogenic fluid management technologies involving two-phase flow and heat transfer are in high demand to successfully procure strategic in-space architectures such as on-orbit fuel depots, in-space refueling system, and nuclear thermal propulsion. However, the unique and extreme thermal properties of cryogenic fluids present distinct challenges, as their thermal-fluid behavior deviates significantly from that of conventional room-temperature fluids. In particular, the fundamental physics of cryogenic flow boiling under reduced or partial gravity remain poorly understood, posing a significant barrier to the application of these technologies for space applications. In order to experimentally investigate the cryogenic flow boiling physics under reduced and partial gravity environment, a parabolic flight rig was designed and constructed. Between 2022 and 2024, three flight campaigns were carried out, yielding a total of 270 parabolas. These efforts successfully produced the world’s first microgravity cryogenic database. In this talk, I will discuss the gravitational effects on cryogenic two-phase flow patterns and interfacial behaviors, using high-speed videos and images obtained from the parabolic flight testing. Taking a step further, I will also explore the impact of reduced and partial gravity on two essential thermal design parameters: (a) heat transfer coefficients and (b) critical heat flux. I will conclude my talk by presenting new design correlations and multiphase computational fluid dynamics models developed based on the microgravity cryogenic database, illustrating their real-life applications with concrete examples.

Biography
Sunjae Kim is a Ph.D. candidate in Mechanical Engineering at Purdue University. His research focuses on understanding the effects of gravity on multiphase thermal-hydraulic characteristics, with a particular emphasis on cryogenic flow boiling physics. His primary goal is to leverage multiphase fluid-thermal science to innovate in-space thermal management systems. Prior to his doctoral studies, he worked as a Research Engineer at the Agency for Defense Development, a national lab in South Korea, where he focused on developing advanced thermodynamic systems for naval defense applications. He has been honored with several professional awards and academic fellowships, including Gold Prize Winner of 4th HVAC Competition from SAREK in 2016, as well as the Frederick N. Andrews Fellowship in 2020 and Bilsland Dissertation Fellowship in 2024 at Purdue University.

MAE Faculty Host: Youngsup Song