E-Thesis 175 views 30 downloads
Efficient and Open-Source Tool for the Prediction of Thermowell Structural Response / CALLUM JONES
Swansea University Author: CALLUM JONES
DOI (Published version): 10.23889/SUthesis.66200
Abstract
Thermowells are widely used in the aid of the measurement of temperature in high velocity or corrosive flow in large industrial installations. They are susceptible to vortex induced vibration which can be a cause of two types of damage; fatigue failure and resonance failure. Hence it is important to...
| Published: |
Swansea University, Wales, UK
2024
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| Institution: | Swansea University |
| Degree level: | Master of Philosophy |
| Degree name: | M.Phil |
| Supervisor: | Gil, A. J., and Rolland, S. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa66200 |
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| Abstract: |
Thermowells are widely used in the aid of the measurement of temperature in high velocity or corrosive flow in large industrial installations. They are susceptible to vortex induced vibration which can be a cause of two types of damage; fatigue failure and resonance failure. Hence it is important to understand the mechanisms that may avoid vortex induced vibration as failure of a thermowell can cause a leak in the pipe or vessel it is installed on. An industry standard for the sizing and installation of a thermowell in order to avoid failure due to vortex induced vibration, hydrostatic pressure or static bending already exists. The standard is thorough and has been amended as recently as 2016 in order to increase safety in working with thermowells. However, it has its shortcomings with some assumptions it makes and when considering unique designs. A unique design of particular interest from industry is that of a cylindrical well with helical strakes attached. This affects the boundary layer of the fluid on the thermowell.In this work, a novel tool is developed for computing the structural response of a thermowell depending on the flow environment in which it is placed in. The tool exploits one-way coupling requiring the physics of fluid flow and solid dynamics. The incompressible Navier-Stokes equations with a RANS turbulence model and a structural modal superposition method are used to solve for the fluid and the solid. An experimental setup was also proposed with the purpose of benchmarking the numerical approach, however, experimental testing was not pursued.The numerical model showed a significant reduction in time dynamic oscillatory force being applied to the thermowell when helical strakes are introduced but an increase in steady state force. Therefore, with the presence of helical strakes, the dynamics stress levels that the thermowell experiences is reduced making the thermowell less susceptible to failure. |
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| Item Description: |
A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information |
| Keywords: |
Thermowell, modal superposition, structural, cylindrical geometry, helical strakes, fluid, k-omega SST, opensource, prediction |
| College: |
Faculty of Science and Engineering |
| Funders: |
European Social Fund via the Welsh Government (WEFO) |