DOI
https://doi.org/10.25772/9MS7-KR52
Author ORCID Identifier
https://orcid.org/0009-0004-9386-8323
Defense Date
2025
Document Type
Dissertation
Degree Name
Doctor of Philosophy
Department
Mechanical and Nuclear Engineering
First Advisor
Lane Carasik
Second Advisor
Radhika Barua
Third Advisor
Gennady Miloshevsky
Fourth Advisor
Harold Ogrosky
Fifth Advisor
Joshua Graves
Abstract
Energy independence and security is important for developing energy production methods that are not impacted by external conditions and with minimal downsides. To this end, new energy technologies are being developed, such as high-Prandtl number fluids, to improve the thermal efficiencies of developing technologies. Modern developing energy systems of interest include solar, nuclear, and fusion power and each have proposed integra- tion with technologies where thermal hydraulic investigations are fundamentally needed. Thermal energy storage is heavily impacted by thermal hydraulics which form the core of effective and efficient storage of heated fluids through thermal stratification and thermo- cline development. Additionally, similar thermal hydraulic scenarios are encountered in medical isotope production targets used in cyclotron facilities. With these technologies there are gaps in performance of systems that use high-Prandtl number fluids such as water, mineral oils, and molten salts. For this work, there are three aims focused on heat transfer enhancements in molten salt heat exchangers, molten salt thermal energy storage and optimizing target design for medical isotope production. To address the first aim, heat exchangers were the primary focus of improvement which was addressed through heat transfer enhancements which aim to increase heat transfer while minimizing pressure drop performance impact. Specifically, the thermal performance study of heat transfer enhancements using internally grooved helical ribs, known as rifled tubes was done using Computational Fluid Dynamics for relevant prototypical conditions. The second aim is focused on studying the performance of sensible thermal energy storage using molten salts for thermal stratification and thermocline development. Specifically, the effects of the injection nozzle angle and location was studied. For the third aim, the production of the medical isotope, 211-At, through irradiating Bismuth metal at increased energy levels using thermal hydraulically optimized targets is focused. In this aim, we used conjugate heat transfer methodologies such as 0-dimensional models as well as single- and multi-objective optimization schemes to elucidate the design space. The sum contribution of these three aims will focus on thermal-hydraulic computational fluid dynamics simulations to improve understanding of high-Prandtl number fluids and their behaviors.
Rights
© James Vulcanoff
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
8-6-2025