Pub Date : 2024-10-11DOI: 10.1016/j.coastaleng.2024.104630
The interaction between extreme waves and a vertical cylinder is a complex process due to the intricate impact physics, three-dimensional effects, and unique characteristics of breaking waves. To improve wave force predictions, an enhanced model based on a finite-water-extent slamming theory that incorporates wave profiles is proposed. In contrast to the infinite-water-extent assumption in typical wave slamming theories, a finite volume of water with dual free surfaces is used, which better captures the wave's boundary conditions. Strip theory and potential flow theory are adopted to calculate sectional wave forces on the cylinder by solving the governing and boundary equations. The wave profiles, which provide the boundary conditions, result in a more realistic distribution of sectional forces than the often-assumed uniform distribution. Comparison with experimental data shows that the proposed model indeed provides more accurate wave force predictions and exhibits a gradual rise in impact force instead of an abrupt change observed in commonly used models.
{"title":"An enhanced model for an extreme wave impacting a vertical cylinder","authors":"","doi":"10.1016/j.coastaleng.2024.104630","DOIUrl":"10.1016/j.coastaleng.2024.104630","url":null,"abstract":"<div><div>The interaction between extreme waves and a vertical cylinder is a complex process due to the intricate impact physics, three-dimensional effects, and unique characteristics of breaking waves. To improve wave force predictions, an enhanced model based on a finite-water-extent slamming theory that incorporates wave profiles is proposed. In contrast to the infinite-water-extent assumption in typical wave slamming theories, a finite volume of water with dual free surfaces is used, which better captures the wave's boundary conditions. Strip theory and potential flow theory are adopted to calculate sectional wave forces on the cylinder by solving the governing and boundary equations. The wave profiles, which provide the boundary conditions, result in a more realistic distribution of sectional forces than the often-assumed uniform distribution. Comparison with experimental data shows that the proposed model indeed provides more accurate wave force predictions and exhibits a gradual rise in impact force instead of an abrupt change observed in commonly used models.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-10DOI: 10.1016/j.coastaleng.2024.104629
The mass source wave-maker is commonly employed for generating water waves in numerical simulations, during which a correct amount of mass is introduced or subtracted from the internal flow region to produce target waves. The method has proven to be effective in producing waves in shallow and intermediate water depths, while its efficiency is declined for short wave generation. The main reason for this efficiency declination is that the internal mass source in deeper water region is not effective to generate short waves with their motions primarily on water surface. In order to overcome this shortcoming, many of the previous numerical treatments have introduced various enhancement factors into the source functions, which are empirically obtained and also violate the law of mass conservation. In this study, we develop a new adaptive internal wave-maker model that can be self-adjusted to suit different wave conditions. The line source starts from the bottom and extends to the computational cell right beneath free surface at each time step. The depth dependent weighting coefficient is introduced to the source function based on the linear wave theory for each wave component. No empirical coefficients are necessary, and the mass conservation is strictly and explicitly enforced. In principle, the method can be applied to all types of linear waves in the entire range of kh. The numerical experiments show that the present method can produce very good results for linear waves with kh up to 16.11, adequate for most of wave conditions in coastal engineering. For generation of fifth-order Stokes waves, the method can be extended straightforwardly for each of five wave components. For irregular waves composed of many linear wave components, different weighting coefficients can be readily calculated for each of them, respectively. As a result, the new model can generate irregular waves with overall better performance of reproducing wave spectrum, whose high-frequency part has been underestimated by previous methods. The numerical experiments also show that the new model can produce better results for focused waves where many linear waves of different frequencies start from the same point with specific phase angles, due to its capability of generating shorter wave components.
{"title":"An adaptive internal mass source wave-maker for short wave generation","authors":"","doi":"10.1016/j.coastaleng.2024.104629","DOIUrl":"10.1016/j.coastaleng.2024.104629","url":null,"abstract":"<div><div>The mass source wave-maker is commonly employed for generating water waves in numerical simulations, during which a correct amount of mass is introduced or subtracted from the internal flow region to produce target waves. The method has proven to be effective in producing waves in shallow and intermediate water depths, while its efficiency is declined for short wave generation. The main reason for this efficiency declination is that the internal mass source in deeper water region is not effective to generate short waves with their motions primarily on water surface. In order to overcome this shortcoming, many of the previous numerical treatments have introduced various enhancement factors into the source functions, which are empirically obtained and also violate the law of mass conservation. In this study, we develop a new adaptive internal wave-maker model that can be self-adjusted to suit different wave conditions. The line source starts from the bottom and extends to the computational cell right beneath free surface at each time step. The depth dependent weighting coefficient is introduced to the source function based on the linear wave theory for each wave component. No empirical coefficients are necessary, and the mass conservation is strictly and explicitly enforced. In principle, the method can be applied to all types of linear waves in the entire range of <em>kh</em>. The numerical experiments show that the present method can produce very good results for linear waves with <em>kh</em> up to 16.11, adequate for most of wave conditions in coastal engineering. For generation of fifth-order Stokes waves, the method can be extended straightforwardly for each of five wave components. For irregular waves composed of many linear wave components, different weighting coefficients can be readily calculated for each of them, respectively. As a result, the new model can generate irregular waves with overall better performance of reproducing wave spectrum, whose high-frequency part has been underestimated by previous methods. The numerical experiments also show that the new model can produce better results for focused waves where many linear waves of different frequencies start from the same point with specific phase angles, due to its capability of generating shorter wave components.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-27DOI: 10.1016/j.coastaleng.2024.104626
Wave overtopping of coastal structures has been studied using physical model experiments with rubble mound breakwaters in shallow water. The mean overtopping discharge is determined for three different foreshore slopes and various hydrodynamic conditions. The hydrodynamic results confirm that energy is transferred to low-frequency waves in very shallow water and that the short waves are in phase with the lower-frequency waves in very shallow water. As a result, the extreme waves (e.g. 2% exceedance wave height) become relatively large in very shallow water due to the energy of the low-frequency waves affecting thereby the wave overtopping. To estimate the amount of energy at the low-frequency waves, an expression is derived which reasonably accurately predicts the low-frequency wave energy (RMSE of 0.06). Considering the non-dimensional overtopping discharge, the existing formulations for the non-dimensional mean wave overtopping discharge perform poorly to reasonably in shallow water with RMSLE ranging from 1.04 to 2.92. A parameter sensitivity study shows that the short-wave steepness, relative crest height and the low-frequency wave height are the most important parameters when predicting the mean overtopping discharge in shallow water. When including the short-wave steepness and relative crest height in an empirical formulation the RMSLE for the current dataset reduces to 0.69. A further increase in accuracy is found when the low-frequency wave height and 2% exceedance wave height are included (RMSLE 0.64).
{"title":"Wave overtopping discharges at rubble mound structures in shallow water","authors":"","doi":"10.1016/j.coastaleng.2024.104626","DOIUrl":"10.1016/j.coastaleng.2024.104626","url":null,"abstract":"<div><div>Wave overtopping of coastal structures has been studied using physical model experiments with rubble mound breakwaters in shallow water. The mean overtopping discharge is determined for three different foreshore slopes and various hydrodynamic conditions. The hydrodynamic results confirm that energy is transferred to low-frequency waves in very shallow water and that the short waves are in phase with the lower-frequency waves in very shallow water. As a result, the extreme waves (e.g. 2% exceedance wave height) become relatively large in very shallow water due to the energy of the low-frequency waves affecting thereby the wave overtopping. To estimate the amount of energy at the low-frequency waves, an expression is derived which reasonably accurately predicts the low-frequency wave energy (RMSE of 0.06). Considering the non-dimensional overtopping discharge, the existing formulations for the non-dimensional mean wave overtopping discharge perform poorly to reasonably in shallow water with RMSLE ranging from 1.04 to 2.92. A parameter sensitivity study shows that the short-wave steepness, relative crest height and the low-frequency wave height are the most important parameters when predicting the mean overtopping discharge in shallow water. When including the short-wave steepness and relative crest height in an empirical formulation the RMSLE for the current dataset reduces to 0.69. A further increase in accuracy is found when the low-frequency wave height and 2% exceedance wave height are included (RMSLE 0.64).</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-27DOI: 10.1016/j.coastaleng.2024.104627
Current effects on waves (CEW) are among the most intricate physical processes in wave evolution. In this study, we used a coupled wave-tide-circulation model for the Northwest Atlantic to investigate current effects on storm waves during Hurricane Igor in 2010. Validated with extensive buoy and altimeter data, the inclusion of CEW in the model significantly improves the accuracy in simulating significant wave heights () by up to 21.3% for a wave buoy. Storm waves experience significant temporal and spatial modulation by multi-scale currents. Storm-driven currents have the most pronounced impact to the right of the storm track, which typically align with wave propagation and reduce by up to 12.1%. The subsequent near-inertial oscillations induce temporal fluctuations of wave convergence and divergence at near-inertial frequencies, which also occurs in regions with strong tidal currents but at tidal frequencies. Furthermore, storm waves are modulated by the Gulf Stream, Labrador Current and associated mesoscale eddies. Overall, these multi-scales yield strong effects on storm waves ( > 3.0 m), significantly modulating (−25.2%–+55.4%) and mean wave periods (−14.9%–+15.7%). The mean wave energy power shows more significant modulation by multi-scale currents, reflecting the combined effects of changing wave states and current-induced transport of wave energy. CEW are governed by the interactive dynamic and kinematic effects. The relative wind effect is the primary mechanism for lower storm waves by reducing energy input to waves and influences downstream wave states. Among kinematic effects, current-induced wave refraction typically plays a dominant role in redistributing wave energy. This study systematically quantified the modulation of storm waves by multi-scale currents and revealed the underlying mechanisms, providing a comprehensive understanding of extreme wave states under coupled ocean dynamics.
{"title":"Convergence and divergence of storm waves induced by multi-scale currents: Observations and coupled wave-current modeling","authors":"","doi":"10.1016/j.coastaleng.2024.104627","DOIUrl":"10.1016/j.coastaleng.2024.104627","url":null,"abstract":"<div><div>Current effects on waves (CEW) are among the most intricate physical processes in wave evolution. In this study, we used a coupled wave-tide-circulation model for the Northwest Atlantic to investigate current effects on storm waves during Hurricane Igor in 2010. Validated with extensive buoy and altimeter data, the inclusion of CEW in the model significantly improves the accuracy in simulating significant wave heights (<span><math><mrow><msub><mi>H</mi><mi>s</mi></msub></mrow></math></span>) by up to 21.3% for a wave buoy. Storm waves experience significant temporal and spatial modulation by multi-scale currents. Storm-driven currents have the most pronounced impact to the right of the storm track, which typically align with wave propagation and reduce <span><math><mrow><msub><mi>H</mi><mi>s</mi></msub></mrow></math></span> by up to 12.1%. The subsequent near-inertial oscillations induce temporal fluctuations of wave convergence and divergence at near-inertial frequencies, which also occurs in regions with strong tidal currents but at tidal frequencies. Furthermore, storm waves are modulated by the Gulf Stream, Labrador Current and associated mesoscale eddies. Overall, these multi-scales yield strong effects on storm waves (<span><math><mrow><msub><mi>H</mi><mi>s</mi></msub></mrow></math></span> > 3.0 m), significantly modulating <span><math><mrow><msub><mi>H</mi><mi>s</mi></msub></mrow></math></span> (−25.2%–+55.4%) and mean wave periods (−14.9%–+15.7%). The mean wave energy power shows more significant modulation by multi-scale currents, reflecting the combined effects of changing wave states and current-induced transport of wave energy. CEW are governed by the interactive dynamic and kinematic effects. The relative wind effect is the primary mechanism for lower storm waves by reducing energy input to waves and influences downstream wave states. Among kinematic effects, current-induced wave refraction typically plays a dominant role in redistributing wave energy. This study systematically quantified the modulation of storm waves by multi-scale currents and revealed the underlying mechanisms, providing a comprehensive understanding of extreme wave states under coupled ocean dynamics.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-26DOI: 10.1016/j.coastaleng.2024.104625
Three phase-resolving weakly dispersive wave models are used for 2DH (2D depth-integrated) computations of large-scale wave-by-wave processes induced by highly energetic sea/swell (SS) forcing near Haleʻiwa on the North Shore of Oʻahu, Hawaiʻi. The computed model results are compared to observations obtained over a nearshore cross-reef transect and from the basin of a small boat harbor. The level of agreement between the model results and observations in complex coastal environments under highly energetic wave forcing, along with the qualitative consistency among the three models, makes these models good candidates for operational applications in nearshore environments exposed to energetic wave forcing conditions.
Spectral analyses inside the harbor and over the reef indicate that all three models generally account for infragravity (IG) spatial modal structures that are consistent with observations and the theory of edge and leaky waves. Over the reef, auto- and cross-spectral analyses reveal that the dominant waveforms are qualitatively reproduced by all three models, as indicated through: (i) the growth of IG wave amplitudes from deeper water to the shallow reef sites; (ii) the agreement of power spectral density peaks at the nearshore locations; and (iii) the remarkable similarity of spatial coherence functions among the models and between the models and observations. The computations of swell entering the small boat harbor at Haleʻiwa demonstrate that the models can successfully reproduce the variability in the narrow IG frequency bands that are spatially dependent and often subject to resonant amplifications.
{"title":"Computations of energetic nearshore waves: Are weakly dispersive phase-resolving models telling the same story?","authors":"","doi":"10.1016/j.coastaleng.2024.104625","DOIUrl":"10.1016/j.coastaleng.2024.104625","url":null,"abstract":"<div><div>Three phase-resolving weakly dispersive wave models are used for 2DH (2D depth-integrated) computations of large-scale wave-by-wave processes induced by highly energetic sea/swell (SS) forcing near Haleʻiwa on the North Shore of Oʻahu, Hawaiʻi. The computed model results are compared to observations obtained over a nearshore cross-reef transect and from the basin of a small boat harbor. The level of agreement between the model results and observations in complex coastal environments under highly energetic wave forcing, along with the qualitative consistency among the three models, makes these models good candidates for operational applications in nearshore environments exposed to energetic wave forcing conditions.</div><div>Spectral analyses inside the harbor and over the reef indicate that all three models generally account for infragravity (IG) spatial modal structures that are consistent with observations and the theory of edge and leaky waves. Over the reef, auto- and cross-spectral analyses reveal that the dominant waveforms are qualitatively reproduced by all three models, as indicated through: (i) the growth of IG wave amplitudes from deeper water to the shallow reef sites; (ii) the agreement of power spectral density peaks at the nearshore locations; and (iii) the remarkable similarity of spatial coherence functions among the models and between the models and observations. The computations of swell entering the small boat harbor at Haleʻiwa demonstrate that the models can successfully reproduce the variability in the narrow IG frequency bands that are spatially dependent and often subject to resonant amplifications.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-26DOI: 10.1016/j.coastaleng.2024.104623
The MoSE barriers system was designed and constructed at the inlets of the Venice Lagoon (Italy) in order to limit and tame the flooding events in the Lagoon areas and in the City. The success of the design and operation of the system has been demonstrated by the significant reduction in the number and intensity of floods in the lagoon since its beginning of operations in 2020. In this study, we investigate the dynamical behavior of the MoSE system at full-scale by analyzing the barriers behavior during the severe storm event of November 22nd, 2022. In particular, the dynamical response of the Chioggia barrier to waves and storm surge is studied in detail. Spectral analysis of field records, barrier and inlet modal analyses and Empirical Orthogonal Functions (EOF) techniques are applied to provide a key for interpreting the actual behavior of such a complex system during a storm event, highlighting dominant frequencies and checking for the occurrence of resonance phenomena. First, a brief review of the experimental and theoretical studies carried out over the past forty years is given. Modal patterns of gates oscillations detected via EOF analysis confirm the presence of the eigenmodes of both the barrier and the inlet; however, the gates oscillations during the considered event are mild and the hydraulic performances of the system are satisfactory for the severe event studied. Further field measurements and future severe events should be studied to reach extended conclusions.
{"title":"Prototype data analysis of the dynamics of the Venice gate-barriers during an extreme storm event","authors":"","doi":"10.1016/j.coastaleng.2024.104623","DOIUrl":"10.1016/j.coastaleng.2024.104623","url":null,"abstract":"<div><div>The MoSE barriers system was designed and constructed at the inlets of the Venice Lagoon (Italy) in order to limit and tame the flooding events in the Lagoon areas and in the City. The success of the design and operation of the system has been demonstrated by the significant reduction in the number and intensity of floods in the lagoon since its beginning of operations in 2020. In this study, we investigate the dynamical behavior of the MoSE system at full-scale by analyzing the barriers behavior during the severe storm event of November 22nd, 2022. In particular, the dynamical response of the Chioggia barrier to waves and storm surge is studied in detail. Spectral analysis of field records, barrier and inlet modal analyses and Empirical Orthogonal Functions (EOF) techniques are applied to provide a key for interpreting the actual behavior of such a complex system during a storm event, highlighting dominant frequencies and checking for the occurrence of resonance phenomena. First, a brief review of the experimental and theoretical studies carried out over the past forty years is given. Modal patterns of gates oscillations detected via EOF analysis confirm the presence of the eigenmodes of both the barrier and the inlet; however, the gates oscillations during the considered event are mild and the hydraulic performances of the system are satisfactory for the severe event studied. Further field measurements and future severe events should be studied to reach extended conclusions.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-24DOI: 10.1016/j.coastaleng.2024.104624
The integration of coastal dunes planted with vegetation and dikes combines traditional infrastructure with dynamic aeolian sediment and ecological processes to enhance coastal resilience. The functioning of such dune-dike hybrid Nature-based Solution strongly depends on aeolian sediment transport and the vertical growth rate of vegetation. We used the AeoLiS numerical model to investigate the relative importance of aeolian and vegetation dynamics in the evolution of a 120 m long and 20 m wide marram grass-planted dune field on a Belgian sandy beach backed by a seawall, constructed in 2021. AeoLiS proved to be a promising tool for predicting these systems, effectively capturing aeolian sediment deposition, vegetation growth, and profile development three years post-construction. Seasonal variations in vegetation trapping efficiency, driven by sediment burial, and seasonal plant growth emerged as important factors controlling dune growth. Profile development discrepancies were attributed to unaccounted biotic and abiotic factors, highlighting the complexity of coastal eco-geomorphological processes. Dunes planted with vegetation wider than 20 m were identified to enhance sediment trapping without an increase in dune height. These findings offer actionable insights for coastal management, promoting strategic dune design and planting approaches to reinforce shoreline resilience. Additionally, the findings underscore the necessity for advancing eco-morphodynamic models and deepening our knowledge of coastal dune dynamics.
{"title":"Vertical growth rate of planted vegetation controls dune growth on a sandy beach","authors":"","doi":"10.1016/j.coastaleng.2024.104624","DOIUrl":"10.1016/j.coastaleng.2024.104624","url":null,"abstract":"<div><div>The integration of coastal dunes planted with vegetation and dikes combines traditional infrastructure with dynamic aeolian sediment and ecological processes to enhance coastal resilience. The functioning of such dune-dike hybrid Nature-based Solution strongly depends on aeolian sediment transport and the vertical growth rate of vegetation. We used the AeoLiS numerical model to investigate the relative importance of aeolian and vegetation dynamics in the evolution of a 120 m long and 20 m wide marram grass-planted dune field on a Belgian sandy beach backed by a seawall, constructed in 2021. AeoLiS proved to be a promising tool for predicting these systems, effectively capturing aeolian sediment deposition, vegetation growth, and profile development three years post-construction. Seasonal variations in vegetation trapping efficiency, driven by sediment burial, and seasonal plant growth emerged as important factors controlling dune growth. Profile development discrepancies were attributed to unaccounted biotic and abiotic factors, highlighting the complexity of coastal eco-geomorphological processes. Dunes planted with vegetation wider than 20 m were identified to enhance sediment trapping without an increase in dune height. These findings offer actionable insights for coastal management, promoting strategic dune design and planting approaches to reinforce shoreline resilience. Additionally, the findings underscore the necessity for advancing eco-morphodynamic models and deepening our knowledge of coastal dune dynamics.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-23DOI: 10.1016/j.coastaleng.2024.104622
The purpose of this study is to investigate the rate of span shoulder propagation under conditions of waves and current. The study analyzed 117 cases from previous and present investigations, which were divided into three categories: pure wave, wave-plus-current, and pure current. Furthering the framework of Sui et al. (2021) for pure current conditions, the relative current strength was included in the present study to incorporate the effects of the wave component in a general wave-plus-current condition, through a systematic dimensional analysis. For a given excess Shields parameter, the pure current case has the largest migration velocity compared to the wave conditions. Incorporating the wave components into the pure current decreases the rate of the span shoulder propagation. A new model is proposed to predict the rate of span shoulder propagation while considering the dependency of current strength, excess Shields parameter, and embedded depth. The new model has a determination coefficient of 0.8, indicating its ability to accurately predict the rate of the span shoulder propagation under general wave and current conditions. Parametric studies show that increasing the excess Shields parameter increases the migration rate while increasing the embedment depth, ratio of the pipe diameter to the grain diameter decreases it.
本研究的目的是调查波浪和水流条件下跨肩的传播速度。本研究分析了以往和当前研究中的 117 个案例，将其分为三类：纯波浪、波浪加水流和纯水流。在 Sui 等人（2021 年）针对纯水流条件的框架基础上，本研究通过系统的维度分析，将相对水流强度纳入到一般波浪加水流条件下的波浪分量的影响中。对于给定的过量希尔兹参数，与波浪条件相比，纯水流情况下的迁移速度最大。在纯电流中加入波浪成分会降低跨肩的传播速度。我们提出了一个新模型来预测跨肩的传播速度，同时考虑了水流强度、过量盾构参数和嵌入深度的相关性。新模型的确定系数为 0.8，表明其能够准确预测一般波浪和水流条件下的跨肩传播速度。参数研究表明，增加过量盾构参数会增加迁移率，而增加嵌入深度和管道直径与晶粒直径之比会降低迁移率。
{"title":"Wave-plus-current induced span shoulder migration in three dimensional scour around submarine pipeline","authors":"","doi":"10.1016/j.coastaleng.2024.104622","DOIUrl":"10.1016/j.coastaleng.2024.104622","url":null,"abstract":"<div><div>The purpose of this study is to investigate the rate of span shoulder propagation under conditions of waves and current. The study analyzed 117 cases from previous and present investigations, which were divided into three categories: pure wave, wave-plus-current, and pure current. Furthering the framework of Sui et al. (2021) for pure current conditions, the relative current strength was included in the present study to incorporate the effects of the wave component in a general wave-plus-current condition, through a systematic dimensional analysis. For a given excess Shields parameter, the pure current case has the largest migration velocity compared to the wave conditions. Incorporating the wave components into the pure current decreases the rate of the span shoulder propagation. A new model is proposed to predict the rate of span shoulder propagation while considering the dependency of current strength, excess Shields parameter, and embedded depth. The new model has a determination coefficient of 0.8, indicating its ability to accurately predict the rate of the span shoulder propagation under general wave and current conditions. Parametric studies show that increasing the excess Shields parameter increases the migration rate while increasing the embedment depth, ratio of the pipe diameter to the grain diameter decreases it.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-23DOI: 10.1016/j.coastaleng.2024.104621
Local scour and wave loading are two key factors that affect the safety of seawalls under tsunami attacks. In this study, the scouring process at the toe of and wave impact force on a vertical seawall under consecutive solitary wave attacks are simulated using a quasi-three-phase (air, water, and sediment) flow model, which models the air and water as a fluid mixture phase and sediment as a solid phase. The air and water interface is modeled by a VOF method and the sediment–fluid interaction is modeled using the Eulerian two-phase flow method. A comparison between the beach profiles with and without the seawall shows that, with a seawall, a deeper scour hole is generated at the toe of the seawall. Besides, the presence of the seawall causes the eroded sediment to be deposited further offshore. The numerical results are then analyzed in detail regarding the flow field and sediment transport process to reveal the mechanisms of the above eroding/depositing patterns. The wave impact force on the seawall is also analyzed to understand the effect of scouring on the wave loading. It is shown that the wave impact force, despite being stochastic for a specific wave, increases in general with the deepening of the scour hole because the latter increases the exposure of the seawall to wave slamming.
{"title":"A quasi-three-phase flow simulation of the interactions between solitary waves and a vertical seawall installed on a sandy beach","authors":"","doi":"10.1016/j.coastaleng.2024.104621","DOIUrl":"10.1016/j.coastaleng.2024.104621","url":null,"abstract":"<div><div>Local scour and wave loading are two key factors that affect the safety of seawalls under tsunami attacks. In this study, the scouring process at the toe of and wave impact force on a vertical seawall under consecutive solitary wave attacks are simulated using a quasi-three-phase (air, water, and sediment) flow model, which models the air and water as a fluid mixture phase and sediment as a solid phase. The air and water interface is modeled by a VOF method and the sediment–fluid interaction is modeled using the Eulerian two-phase flow method. A comparison between the beach profiles with and without the seawall shows that, with a seawall, a deeper scour hole is generated at the toe of the seawall. Besides, the presence of the seawall causes the eroded sediment to be deposited further offshore. The numerical results are then analyzed in detail regarding the flow field and sediment transport process to reveal the mechanisms of the above eroding/depositing patterns. The wave impact force on the seawall is also analyzed to understand the effect of scouring on the wave loading. It is shown that the wave impact force, despite being stochastic for a specific wave, increases in general with the deepening of the scour hole because the latter increases the exposure of the seawall to wave slamming.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-20DOI: 10.1016/j.coastaleng.2024.104620
The recent destructive hurricane seasons and concerns related to the future influence of climate change have increased the relevance of coastal storm hazards and, in particular, of storm surge hazard estimation when discussing the resilience of coastal communities. This hazard is generally represented as surge inundation probabilities over a large number of individual locations in the geographic domain of interest, and is typically assessed utilizing an ensemble of storm scenarios (i.e., storm events) that are representative of the regional climatology. This paper investigates the storm ensemble selection within this setting, with the objective of identifying a small number of storm scenarios that are consistent with some chosen hazard descriptions over a large geographic region. Beyond the storm events, the occurrence rates (i.e., weights) are also updated. Following past works, a two-stage optimization is adopted for the storm selection. The inner-loop identifies the occurrence rates for a given storm subset, formulating the problem as a linear programming optimization for the sum of absolute deviation for the predicted hazard. The outer-loop searches for the best subset with the desired number of storms, adopting a genetic algorithm integer optimization for minimizing the aforementioned deviation. This work extends this implementation to extended coastal regions, with many locations of interest. In this case, it is computationally intractable to consider all the locations in the domain within the linear programming formulation, and for this reason, a subset of representative locations is chosen through cluster analysis. The hazard description for only these locations is used in the storm ensemble selection. For clustering, different strategies using correlation between locations based on geospatial information, surge response, or a combination of both are examined. Additionally, the correlation in the hazard description is better integrated into the storm selection by establishing a modification of the objective function adopted for the outer optimization loop. Applications to different North Atlantic coastal domains are presented as case studies.
{"title":"Hazard-consistent scenario selection for long-term storm surge risk assessment over extended coastal regions","authors":"","doi":"10.1016/j.coastaleng.2024.104620","DOIUrl":"10.1016/j.coastaleng.2024.104620","url":null,"abstract":"<div><div>The recent destructive hurricane seasons and concerns related to the future influence of climate change have increased the relevance of coastal storm hazards and, in particular, of storm surge hazard estimation when discussing the resilience of coastal communities. This hazard is generally represented as surge inundation probabilities over a large number of individual locations in the geographic domain of interest, and is typically assessed utilizing an ensemble of storm scenarios (i.e., storm events) that are representative of the regional climatology. This paper investigates the storm ensemble selection within this setting, with the objective of identifying a small number of storm scenarios that are consistent with some chosen hazard descriptions over a large geographic region. Beyond the storm events, the occurrence rates (i.e., weights) are also updated. Following past works, a two-stage optimization is adopted for the storm selection. The inner-loop identifies the occurrence rates for a given storm subset, formulating the problem as a linear programming optimization for the sum of absolute deviation for the predicted hazard. The outer-loop searches for the best subset with the desired number of storms, adopting a genetic algorithm integer optimization for minimizing the aforementioned deviation. This work extends this implementation to extended coastal regions, with many locations of interest. In this case, it is computationally intractable to consider all the locations in the domain within the linear programming formulation, and for this reason, a subset of representative locations is chosen through cluster analysis. The hazard description for only these locations is used in the storm ensemble selection. For clustering, different strategies using correlation between locations based on geospatial information, surge response, or a combination of both are examined. Additionally, the correlation in the hazard description is better integrated into the storm selection by establishing a modification of the objective function adopted for the outer optimization loop. Applications to different North Atlantic coastal domains are presented as case studies.</div></div>","PeriodicalId":50996,"journal":{"name":"Coastal Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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