Term of Award

Fall 2025

Degree Name

Master of Science, Mechanical Engineering

Document Type and Release Option

Thesis (open access)

Copyright Statement / License for Reuse

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

Department

Department of Mechanical Engineering

Committee Chair

Sevki Cesmeci

Committee Member 1

Prakashbhai Bhoi

Committee Member 2

Priya Goeser

Abstract

Supercritical carbon dioxide (sCO2) Brayton cycles are a strong contender for future power generation systems due to their high thermal efficiency and compact nature. Sealing is one of the key challenges presented by such systems that has a direct impact on the system's overall efficiency. This research is the first experimental study to investigate the deformation behavior of an elastohydrodynamic (EHD) seal made from bearing-grade polyether ether ketone (PEEK). A testing apparatus was developed to integrate four strain gauges positioned along the seal to quantify the deformation occurring up to pressures of 13 MPa. Mass flow rate measurements were obtained to evaluate the leakage performance. These results showed that the EHD began throttling at 7 MPa of inlet pressure, reaching a maximum leakage of 8.84 g/s ± 0.43 g/s, reducing to 4.76 g/s ± 0.37 g/s at 13 MPa. The maximum compressive strain of –1.047 x 10-3 was found to occur near the seal base at 13 MPa. This confirms that the deformation of the EHD seal is pressure-dependent and primarily occurs in the lower region where the throttling effect occurs. These results contribute to advancing sealing technology for sCO2 turbomachinery by providing the first experimental evidence of deformation-driven leakage reduction in an EHD seal.

Research Data and Supplementary Material

No

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