Doctoral Dissertations
Date of Award
12-2023
Degree Type
Dissertation
Degree Name
Doctor of Philosophy
Major
Energy Science and Engineering
Major Professor
Michael Milan Kirka
Committee Members
Sudarsanam Suresh Babu, Stephanie Carmella TerMaath, Brett Gibson Compton
Abstract
To meet cleaner energy goals and increasing demand, energy systems such as gas turbines and power plants are required to be operated under harsh loading conditions like higher temperatures and pressures, fluctuating loads, and corrosive environments. Advanced manufacturing techniques such as additive manufacturing (AM) have put us on the trajectory for next-generation system designs, allowing complex geometries and high-temperature alloys with tailored material properties. We need new and systematic design philosophies to use AM's unique characteristics prudently. For a given functionality, nature tends to provide similar solutions in animate and inanimate structures. We propose to take inspiration from nature's repetitive solutions and implement them for real-world applications for the next-generation system.
In this dissertation, we first identify a structured approach and consequently categorize these repetitive solutions as a class of solutions for a given functionality. The class of solutions is devised and optimized while solving two real-world problems. The first problem is ash deposition, which is common for different components in power plants and gas turbines. To reduce deposition in power plants on superheater tubes, we propose to leverage an aerodynamically shaped tube, one of the solutions from the classes offered by nature, introducing a macro-level morphology change leveraging the laser powder bed fusion method. The proposed shaped tube performed better than circular tubes in providing more laminar flow around the tube, thus reducing the propensity of ash deposition. Additionally, we also showed how to reduce the circumferential thermal stress, potentially improving the tube's creep life. The second problem is introducing cooling channels for high-pressure turbine applications. Similar to solutions existing in nature, where heat exchange is enhanced by modifying the surface texture, we propose to modify the surface morphology of the internal cooling wall by introducing multiscale micro features enabled through laser powder bed fusion to enhance the surface area and thus improve heat transfer. The proposed design demonstrates designs that are better than AM internal cooling channel designs previously discussed in the literature. We recommend emulating nature's governing approach for repeating its solution in varying-sized creatures through certain laws. We suggest generalizing solutions for differently sized components by identifying relationships between design parameters and component size. To our knowledge, this is one of the first works that attempts to codify and validate a nature-inspired design strategy for high-temperature applications.
Recommended Citation
Singh, Vanshika, "Additively Manufactured Nature Inspired Morphology for Redesign: Advancing Next Generation Energy Systems. " PhD diss., University of Tennessee, 2023.
https://trace.tennessee.edu/utk_graddiss/8971