A TWO-PHASE CFD ANALYSIS OF GEYSERING WITH APPLICATIONS TO THERMOSYPHONS AND LOW PRESSURE POOL BOILING

Under certain operating conditions, thermosyphons can experience a sharp periodic increase in pressure of 30% or more known as geysering. This can lead to fatigue or bursting of the pressure vessel giving an immediate loss in cooling capability and a safety concern. The current work presents a computational model for studying the fluid dynamics of geysering within a two phase closed thermosyphon. Phase change is modeled via source terms in the governing equations and the resulting phase motion is compared to experimental data from literature. The model can resolve the fluid motion of both phases during the slug growth, bursting and draining stages with good qualitative agreement. The model also correctly predicts the pressure rising rate during the growth stage, the peak pressure and timescale of peak pressure compared to ensemble average empirical data. The simulation setup, parameter sensitivity, and current limitations of the model are discussed in detail. Future work is needed to resolve the pressure decay after bursting and various recommendations are given.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Nuclear, Plasma, Radiolgc Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2023

Author dc:creator

• Ciccotosto, Bruce Edward

Contributors dc:contributor

• Brooks, Caleb S
• Grunloh, Timothy P
• Uddin, Rizwan

• Cfd
• Multiphase
• Fluid Dynamics
• Heat Transfer
• Thermosyphons
• Heat Pipes

Statement dc:rights

• Copyright 2023 Bruce Ciccotosto

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/121550

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F121550