Tsunamis have caused severe damage to coastal communities and associated infrastructure over the past decades. Thus, researchers deemed necessary to investigate and better understand the mechanisms loading associated with tsunami waves and the inundation caused by them. Over the past few years, researchers have demonstrated that the dam-break waves are hydrodynamically similar to the onshore propagation of tsunami inundation; hence, dam-break waves are now widely used to investigate tsunami impacts. Various studies related to dam-break waves have been conducted to investigate their characteristics: the kinematic behavior, including free surface profiles, wave height, wave front velocity, and dynamics including the impact pressure and associated force. Most dam-break experiments have been conducted on a horizontal bed, in a tank or a flume, while few studies had employed sloped surfaces. However, natural and artificial beaches usually have slopes ranging from 0-degrees to 20-degrees (or more).
In this study, downstream slopes are considered to investigate the influence of slope effects on the kinematic behaviors and associated hydrodynamic loadings due to dam-break waves. The Volume of Fluid method (VOF) code of the OpenFOAM and the Smoothed Particle Hydrodynamics (SPH) code of the DualSPHysics were applied to reproduce the results of physical tests and provide a comparison with the experimental results. First, existing boundary treatment methods in the SPH were studied and compared to a self-developed code in order to select the best performing method by checking the flow behaviors. In the second part of the thesis, experimental investigation of the impact of dam-break induced surges over a horizontal bed against a vertical wall was conducted by analysing the rapidly varying correlation between the wave height and the associated dynamic pressure. In the third part of this study, three different downstream slopes were added in the experimental setup to investigate the beach effects on the kinematics of dam-break flow, including the free surface profiles, wave height, wave front location and its velocity. In the last part, the impact dynamic pressure on the vertical straight wall from the horizontal and sloped cases were captured to investigate the slope effects on the hydrodynamic loading. The impact force integrated from the dynamic pressure was determined with a simplified calculation formula. In addition, the physical experiments were also reproduced by the numerical models of OpenFOAM and DualSPHysics to compare and investigate their accuracy and to analyze the differences between the physical tests and numerical simulations.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/44389 |
| Date | 15 December 2022 |
| Creators | Liu, Shilong |
| Contributors | Nistor, Ioan, Mohammadian, Abdolmajid |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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