Graduation Semester and Year

Summer 2025

Language

English

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Mechanical Engineering

Department

Mechanical and Aerospace Engineering

First Advisor

Dr. Dereje Agonafer

Abstract

The increasing power density and thermal demand from next-generation data center technologies are rapidly exceeding the limits of traditional air cooling, prompting an industry-wide transition toward liquid cooling solutions. This study provides a comprehensive assessment of single-phase liquid cooling in data centers, evaluating its thermal performance, fluid integrity, and system resiliency. Experimental investigations were conducted on both direct-to-chip (D2C) and single-phase immersion cooling configurations. The resiliency of a liquid-to-liquid (L2L) in-row coolant distribution unit (CDU) was analyzed under various operational and failure scenarios, including total and partial primary flow loss, pump failures, and CDU failover events. Results reveal that quick-acting redundancy is crucial to mitigate rapid temperature rises that can occur within minutes during primary cooling failures. Further, corrosion analyses of key wetted materials (copper, brass, stainless steel 304/316) were performed using ASTM D1384 and D8040 standards, benchmarking multiple commercial PG-25 liquid coolants and PAO 2( Dielectric oil). Findings show significant variation in material compatibility and loss rates depending on coolant formulation, emphasizing the need for robust corrosion inhibitor chemistries to ensure long-term system reliability. Finally, single-phase immersion cooling was experimentally evaluated with several heatsink and cold plate geometries. Micro-channeled cold plates demonstrated the highest heat-flux dissipation (up to 172W/cm²) and lowest thermal resistance (~0.041°C/W), outperforming traditional skived fin designs, though oden at the cost of higher flow impedance. Collectively, the results underscore the growing potential of advanced single-phase liquid cooling architectures to meet future data center requirements, provided fluid chemistry, thermal design, and system redundancy are holistically optimized for reliability and efficiency.

Keywords

Data Center, Thermal Performance, Liquid Cooling, System Resiliency, Fluid Integrity, Corrosion, Single-Phase Immersion cooling

Disciplines

Heat Transfer, Combustion

License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Available for download on Thursday, August 12, 2027

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