Scholarlink

<p>Tsunamis often approach the coast as leading-depression waves, lowering the water level prior to inundation. Commonly used model waveforms, such as solitary waves, do not capture this feature, and the effects of the leading depression on wave runup and swash dynamics remain insufficiently quantified. This study investigates the runup of leading-depression N-waves (LDNs) on uniform slopes using a two-model numerical approach, in which LDN generation by a piston-type wavemaker is simulated using computational fluid dynamics and subsequent wave propagation and runup are modeled using a non-hydrostatic wave model. This approach enables efficient simulation of a large number of cases while providing access to detailed flow field information. The results show that LDNs dissipate more energy during runup than solitary waves of the same amplitude, indicating stronger wave breaking. For the representative case pair S17n-N25n, the relative energy loss during runup increases from <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(13.7\%\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>13.7</mn> <mo>%</mo> </mrow> </math></EquationSource> </InlineEquation> for the solitary wave to <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(27.6\%\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>27.6</mn> <mo>%</mo> </mrow> </math></EquationSource> </InlineEquation> for the comparable type A LDN. Despite sometimes producing lower maximum runup, LDNs generate higher shoreline velocities on steeper slopes (e.g., 1&#xa0;:&#xa0;10). The influence of slope inclination is significant: on milder slopes (e.g., 1&#xa0;:&#xa0;40), increased energy dissipation reduces both runup and shoreline speed, and the differences between LDNs and solitary waves diminish due to extended shoaling. These results quantitatively support experimental observations and hypotheses regarding the role of the leading depression, showing that, compared to solitary waves of the same amplitude, LDNs involve stronger energy dissipation and can induce faster swash flows even when their runup is lower, implying potentially greater swash-zone impact.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Numerical Investigation of the Runup of Leading-Depression N-Waves Using a Two-Model Approach

  • 期刊论文

  • 发表日期：

    2026年7月17日

查看全文
  • Peter H.-Y. Lo,
  • Pin-Chen Ko

摘要

Tsunamis often approach the coast as leading-depression waves, lowering the water level prior to inundation. Commonly used model waveforms, such as solitary waves, do not capture this feature, and the effects of the leading depression on wave runup and swash dynamics remain insufficiently quantified. This study investigates the runup of leading-depression N-waves (LDNs) on uniform slopes using a two-model numerical approach, in which LDN generation by a piston-type wavemaker is simulated using computational fluid dynamics and subsequent wave propagation and runup are modeled using a non-hydrostatic wave model. This approach enables efficient simulation of a large number of cases while providing access to detailed flow field information. The results show that LDNs dissipate more energy during runup than solitary waves of the same amplitude, indicating stronger wave breaking. For the representative case pair S17n-N25n, the relative energy loss during runup increases from \(13.7\%\) 13.7 % for the solitary wave to \(27.6\%\) 27.6 % for the comparable type A LDN. Despite sometimes producing lower maximum runup, LDNs generate higher shoreline velocities on steeper slopes (e.g., 1 : 10). The influence of slope inclination is significant: on milder slopes (e.g., 1 : 40), increased energy dissipation reduces both runup and shoreline speed, and the differences between LDNs and solitary waves diminish due to extended shoaling. These results quantitatively support experimental observations and hypotheses regarding the role of the leading depression, showing that, compared to solitary waves of the same amplitude, LDNs involve stronger energy dissipation and can induce faster swash flows even when their runup is lower, implying potentially greater swash-zone impact.