Graduation Semester and Year
Spring 2026
Language
English
Document Type
Thesis
Degree Name
Doctor of Philosophy in Mechanical Engineering
Department
Mechanical and Aerospace Engineering
First Advisor
Dr. Dereje Agonafer
Second Advisor
Dr. Miguel Amaya
Third Advisor
Dr. Amir Ameri
Fourth Advisor
Dr. Yogesh Fulpagare
Fifth Advisor
Dr. Saket Karajgikar
Abstract
As data centers evolve to support rapidly growing computational demands from artificial intelligence and high‑performance computing, advanced liquid cooling technologies have become essential for managing heat, efficiency, and long‑term reliability. This comprehensive research portfolio investigates reliability, degradation mechanisms, and contamination effects in both single‑phase direct‑to‑chip liquid cooling and two‑phase immersion cooling systems. First, the reliability of 25% propylene glycol single‑phase coolants is evaluated using the ASTM D1384 standard to quantify corrosion behavior of key wetted metals (copper, solder‑coated brass, brass, steel, cast iron, and cast aluminum) and to compare the effectiveness of corrosion inhibitor packages from multiple vendors. Complementing this chemistry‑focused work, an experimental direct‑to‑chip cold plate loop is developed to study the impact of elevated flow rates beyond ASHRAE velocity guidelines on copper cold plates and EPDM hose materials, assessing erosion through changes in surface morphology, thermal resistance, pressure drop, and coolant chemistry via SEM, optical microscopy, and ICP‑MS. To isolate hose‑specific effects, a separate campaign examines the erosion and degradation of EPDM hoses under high‑velocity, elevated‑temperature conditions exceeding PARKER’s recommended limits, using a stainless‑steel loop architecture to attribute measured changes in surface integrity, coolant properties, and FTIR signatures specifically to hose–coolant interactions. In parallel, the susceptibility of single‑phase liquid‑cooled data center loops to biological contamination is explored by studying bio‑growth in cross‑mixed coolants after incomplete flushing, using both stagnant coupon tests and operating cold‑plate loops to quantify microbial proliferation and its implications for fouling, corrosion, and thermal performance. Finally, the work extends to two‑phase immersion cooling through a long‑term reliability study of servers and individual components immersed in a developmental dielectric refrigerant with and without contamination by moisture and plasticizers, tracking chip temperatures, thermal resistance, fluid health, and thermally aged component surfaces over several months. Collectively, these studies provide a multi‑scale understanding of coolant reliability, material degradation, bio‑contamination, and fluid–component interactions, offering practical guidance for designing more durable, reliable, and efficient liquid‑cooled data center infrastructures.
Keywords
Keywords: Data center cooling; liquid cooling; direct-to-chip cooling; coolant reliability; corrosion inhibition; coolant compatibility; erosion; EPDM hose degradation; copper cold plates; bio-growth; two-phase immersion cooling; plasticizer contamination; thermal resistance; high-performance computing.
Disciplines
Heat Transfer, Combustion
License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Recommended Citation
Chinthaparthy, Lochan Sai Reddy, "Multi-Mechanism Assessment of Coolant Technologies for Data Center Thermal Management: Corrosion Inhibition, Erosion Behavior, & Long-Term Reliability in Immersion Systems" (2026). Mechanical and Aerospace Engineering Dissertations. 6.
https://mavmatrix.uta.edu/mechaerospace_dissertations2/6