Term of Award

Summer 2022

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

Hayri Sezer

Abstract

Supercritical CO2 (sCO2) power cycles are next generation power technologies offering improved efficiency, lower customer costs, and less water usage. They hold significant potential in many different industries such as nuclear power production, ship propulsion, geothermal power, solar power, and fossil fuel power plants. One of the largest hurdles preventing this milestone is the lack of suitable shaft seals for sCO2 operating conditions. This component issue needs to be addressed for the next generation nuclear turbine and compressor development to progress. In this study, a novel Elastohydrodynamic (EHD) seal is proposed. This proposed design is capable of handling high pressure and high temperature while being a scalable shaft seal for sCO2 turbomachinery. The potential benefit of this design includes low leakage, minimal wear, low cost, and no stress concentration. The focus of this study was to perform a proof-of-concept study utilizing physics-based computer simulations. A Fluid-Structure-Interaction (FSI) modeling approach was utilized, and the simulations were carried out in COMSOL Multiphysics software. The results indicated that the proof-of-concept study was successfully demonstrated. The leakage rate obtained from the physics-based computer simulations followed a quadratic form with a peak at m = 0.075 kg/s at Pin = 15 MPa and then decaying to less than m = 0.040 kg/s at Pin = 30 MPa. This trend signifies that the design has the potential to be optimized and be tailored to be a solution to the shaft sealing issues found during the operation of sCO2 turbomachinery.

Research Data and Supplementary Material

No

Available for download on Thursday, June 08, 2023

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