Yang, Yifeng;
(2023)
Interaction between Waves / Currents and Structures in an Ice-Covered Channel.
Doctoral thesis (Ph.D), UCL (University College London).
Preview |
Text
Yang_10181193_thesis.pdf Download (12MB) | Preview |
Abstract
The advent of global warming has given rise to promising prospects for the establishment of novel maritime transportation networks across the Arctic region. However, in order to protect the environment, engineering efforts in polar areas must carefully consider their ecological impact. This necessitates strict standards for the reliability of polar marine equipment, which leads to an increased research interest in hydrodynamic problems specific to polar and other cold regions. Compared with the general marine environment, the nature of wave and current loads in the polar environment is very different, and its unique floating ice will also have a complex impact on the hydrodynamic performance of the structure. In addition, for large-scale sea ice, waves propagate in the form of hydroelastic waves. How to accurately predict the load of ships, offshore platforms and other structures in sea ice environment is very important for engineering safety. Hence, this study established and solved some representative wave / current – ice sheet – structure coupled hydrodynamics problems. This study focuses on large extended ice sheets on the water surface and their interactions with waves, structures in a frozen channel. In contrast to free surface channels, hydroelastic waves in icy water channels exhibit strong coupling between water motion and ice sheet vibration, with significant influence from the physical conditions at the edges of the ice sheets. Consequently, hydrodynamics in icy water channels are much more complicated than those in free surface channels. Besides, due to the side walls, the wave-ice-ice sheet interactions in channels are also different from those in unbounded oceans. This thesis investigates the following physical scenarios in an ice-covered channel using the velocity potential theory for fluid flow and Kirchhoff-Love plate theory for ice sheets: 1). the interaction between a uniform current and a submerged horizontal cylinder in a channel with an ice cover; 2). the wave diffraction by a vertical circular cylinder standing in an ice-covered channel; 3). the hydroelastic wave interaction with a circular crack in an ice sheet. Extensive results are provided for the hydrodynamic forces, shear force on the bodies, and wave profiles. A detailed focus on phenomena near the natural frequencies or critical Froude number of the channel is discussed in detail. The research results have practical applications for various engineering and scientific challenges. In particular, 1). Assessing the wave / current loads and stability of the underwater vehicles beneath an ice sheet, which is beneficial to the design of underwater vehicles used for polar region exploration. Besides, through analysing the loads on ice sheets, the potential for ice breakage caused by waves / loads generated by the motion of underwater objects is discussed. This study can be used to form new ideas to break ice sheets, especially in narrow channels where icebreakers cannot work. 2). Understanding the hydrodynamic properties of cylindrical structures in icy water regions and shedding insight into the loads of relevant offshore structures. The proposed methods and obtained results can be used to predict the wave / ice loads on offshore structures working in polar regions and further guide their design. 3). Investigating water waves diffracted by cracks in an ice sheet, which is helpful in understanding the possible influence on the variation of cracks or the entire polar environment by ocean waves and engineering activities.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Interaction between Waves / Currents and Structures in an Ice-Covered Channel |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2023. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Mechanical Engineering |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10181193 |
Loading...
Loading...Loading...Loading...Archive Staff Only
 |
View Item |
