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

Ciccotosto, Bruce Edward

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

Description

Title

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

Author(s)

Ciccotosto, Bruce Edward

Issue Date

2023-07-21

Director of Research (if dissertation) or Advisor (if thesis)

Brooks, Caleb S

Committee Member(s)

• Grunloh, Timothy P
• Uddin, Rizwan

Department of Study

Nuclear, Plasma, & Rad Engr

Discipline

Nuclear, Plasma, Radiolgc Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• CFD
• multiphase
• fluid dynamics
• heat transfer
• thermosyphons
• heat pipes

Abstract

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.

Graduation Semester

2023-08

Type of Resource

Thesis

Copyright and License Information

Copyright 2023 Bruce Ciccotosto

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