Applied Ocean Research最新文献_第9页

Numerical investigation on the amplitude and mechanics of internal solitary waves generated by the gravity collapse method 重力塌缩法产生的内孤波的振幅和力学数值研究

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-07-17 DOI: 10.1016/j.apor.2024.104127

{"title":"Numerical investigation on the amplitude and mechanics of internal solitary waves generated by the gravity collapse method","authors":"","doi":"10.1016/j.apor.2024.104127","DOIUrl":"10.1016/j.apor.2024.104127","url":null,"abstract":"<div><p>The gravity collapse method is a commonly used approach to generate internal solitary waves (ISWs) in experimental or numerical tanks. Presently, the correlation between the wave-making parameters and the amplitude of the ISW produced via this approach is not well understood. The research presents a suggested amplitude expression that is derived from direct numerical simulations, dimensional analysis, and restricted linear regression. To our best knowledge, the expression is first presented in this paper and can be utilized as a useful tool to produce ISW with a specific amplitude. While the formula is often effective in predicting the ISW amplitude, it exhibits a slight inaccuracy in situations where the initial level difference is small and the collapse region is long. This is because the initial potential energy of the collapse region is not fully transformed into ISW energy. Furthermore, this research illustrates the mechanics of the collapse process and concludes that the near-bed horizontal velocities and transport properties induced by large-amplitude ISWs are inherent characteristics rather than being caused by the unstable process of wave generation.</p></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141636973","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}

引用次数: 0

Verification and validation of a coupled CFD–FEM approach with overset structured grid through free decay and regular wave tests 通过自由衰减和规则波试验，验证和确认采用超集结构网格的 CFD-FEM 耦合方法

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-07-17 DOI: 10.1016/j.apor.2024.104126

{"title":"Verification and validation of a coupled CFD–FEM approach with overset structured grid through free decay and regular wave tests","authors":"","doi":"10.1016/j.apor.2024.104126","DOIUrl":"10.1016/j.apor.2024.104126","url":null,"abstract":"<div><p>This paper presents a comprehensive verification and validation study applied to the hydrodynamic analysis of a semi-submersible Floating Offshore Wind Turbine (FOWT) platform. The numerical simulation is conducted using a coupled Computational Fluid Dynamics-Finite Element Method (CFD–FEM) approach. The CFD program incorporates an overset grid interpolation method, facilitating a more systematic grid refinement in the estimation of discretization uncertainties. A mooring analysis program, based on the FEM scheme, is integrated with the CFD program to simulate the dynamic responses of mooring system. The necessity of the nonlinear mooring model is demonstrated by comparing solutions with a comparative test using a linear mooring model. The verification study, based on a least-squares-based extrapolation method, quantifies the spatial and temporal discretization errors of the numerical model. The numerical solutions based on the baseline model are further validated against the model test measurements. A pitch free decay model test and a regular wave model test conducted within the OC5 project are utilized for the verification and validation study. Results from both tests demonstrate the reliability and accuracy of the coupled method.</p></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141636974","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}

引用次数: 0

Failure envelopes of rigid tripod pile foundation under combined vertical-horizontal-moment loadings in clay 粘土中垂直-水平-弯矩联合荷载作用下刚性三脚架桩基的破坏包络线

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-07-16 DOI: 10.1016/j.apor.2024.104131

{"title":"Failure envelopes of rigid tripod pile foundation under combined vertical-horizontal-moment loadings in clay","authors":"","doi":"10.1016/j.apor.2024.104131","DOIUrl":"10.1016/j.apor.2024.104131","url":null,"abstract":"<div><p>The problem considered in this computational study is for the bearing capacity determination of three-dimensional (3D) rigid tripod-pile groups subjected to combined vertical (<em>V</em>), horizontal (<em>H</em>), and bending moment (<em>M</em>) loads. Using the adaptive 3D finite element limit analysis (FELA) coupled with lower bound, upper bound and mixed Gauss element formulations, numerical results are compared with those of the previous study under a single-component loading (<em>V</em>, or <em>H,</em> or <em>M</em>). The failure envelope in the 3D <em>V</em>–<em>H</em>–<em>M</em> loading space is then constructed, and several failure mechanisms presented to complement the discussions on the complex 3D responses. This is followed by a parametric study for the various factors such as the pile length, pile spacing, pile-soil adhesion factors as well as the loading direction angle. Finally, a closed-form design expression of failure envelopes considering the abovementioned influential parameters and the combined load are derived. Noting that the current industry-based design procedures for tripod-pile groups are rarely found, the outcome of the present study can be used with great confidence in design practice.</p></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141623112","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}

引用次数: 0

Numerical investigation of the fully nonlinear wave force on a vertical cylinder in shallow water using Green-Naghdi theory 利用格林-纳格迪理论对浅水中垂直圆柱体上的全非线性波力进行数值研究

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-07-16 DOI: 10.1016/j.apor.2024.104117

引用次数: 0

On some properties of the pressure in nonlinear two-dimensional potential flow with a free surface 关于有自由表面的非线性二维势流中压力的一些特性

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-07-16 DOI: 10.1016/j.apor.2024.104123

引用次数: 0

Ocean non-linear energy harvesting (NEH) with a buckled piezoelectric beam 利用降压压电横梁进行海洋非线性能量采集（NEH）

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-07-15 DOI: 10.1016/j.apor.2024.104115

Moslem Heidari, Gholam Hossein Rahimi, Saeed Bab

{"title":"Ocean non-linear energy harvesting (NEH) with a buckled piezoelectric beam","authors":"Moslem Heidari, Gholam Hossein Rahimi, Saeed Bab","doi":"10.1016/j.apor.2024.104115","DOIUrl":"https://doi.org/10.1016/j.apor.2024.104115","url":null,"abstract":"This paper presents a new energy harvesting method using a buckled beam with a piezoelectric layer inside a buoy. The buoy is designed as a hemispherical point energy absorber and is connected to the sea bed. Two piezoelectric harvesters are placed inside the buoy in horizontal and vertical directions to capture the rotational motion of water particles on the sea surface. Masses are added to the middle of the beams to enhance the system's harvesting behavior. The equations of motion of the system are obtained using the Hamilton principle. These six coupled non-linear equations are solved using the Runge-Kutta numerical method. The dynamic behavior of the buoy and the buckled beam and the energy harvesting system's electrical behavior are analyzed. An analytical method of complexification-averaging is also examined and found to produce results similar to those of the numerical method. A simplified finite element model is presented to show that the displacement magnitude peak of the response obtained in the numerical solution method can be accepted. The study investigates the effects of limited changes in parameters such as frequency and amplitude of waves, electrical circuit resistance, piezoelectric layer characteristics, and buckled beam characteristics on the system behavior. It is shown that wave amplitude has a more significant role in energy production.","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785269","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}

引用次数: 0

Nonlinear wave resonance by four bottom-mounted cylinders in a uniform current using a higher order finite element method 使用高阶有限元法计算均匀电流中四个底装圆柱体的非线性波共振

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-07-15 DOI: 10.1016/j.apor.2024.104125

C.Z. Wang, J.M. Ren, Y.F. Yang, H. Ge

引用次数: 0

ConvTrans-CL: Ocean time series temperature data anomaly detection based context contrast learning ConvTrans-CL：基于上下文对比学习的海洋时间序列温度数据异常检测

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-07-14 DOI: 10.1016/j.apor.2024.104122

{"title":"ConvTrans-CL: Ocean time series temperature data anomaly detection based context contrast learning","authors":"","doi":"10.1016/j.apor.2024.104122","DOIUrl":"10.1016/j.apor.2024.104122","url":null,"abstract":"<div><p>Ocean temperature data anomaly detection is instrumental in monitoring environmental changes and implementing measures to alleviate adverse consequences. This holds immense importance for marine environmental observation and scientific inquiry. However, existing anomaly detection methods encounter significant challenges in extracting features from data, which severely affects the performance of anomaly detection. Existing models have limitations in capturing the local contextual distribution features and high stochastic distribution trends of ocean temperature data. Therefore, this paper introduces the ConvTrans-CL model, which integrates the Transformer encoder with causal convolution and employs a contrastive learning approach. Causal convolution extracts the distributional features of short-time subsequences within a sliding window and integrates them into the self-attention mechanism, enabling the model to focus on the localized features of the data. Contrastive learning efficiently captures the long-range dependencies of time-series data by distinguishing between pairs of subsequences with adjacent time intervals and pairs of non-adjacent subsequences. This enables the model to capture the trend of high stochasticity in the distribution of the temperature data. Finally, we select temperature data from two sea areas that are susceptible to multiple environmental factors for experiments and compare the feature extraction and anomaly detection capabilities of ConvTrans-CL with other methods, confirming the superior performance of our method.</p></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141623109","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}

引用次数: 0

Experimental study of jet and cavity coupling under vertical motion of underwater vehicle 水下航行器垂直运动时射流与空腔耦合的实验研究

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-07-14 DOI: 10.1016/j.apor.2024.104124

Guilin Wang, Wenjun Wang, Tongyun Zhang, Cong Wang

{"title":"Experimental study of jet and cavity coupling under vertical motion of underwater vehicle","authors":"Guilin Wang, Wenjun Wang, Tongyun Zhang, Cong Wang","doi":"10.1016/j.apor.2024.104124","DOIUrl":"https://doi.org/10.1016/j.apor.2024.104124","url":null,"abstract":"<div><p>After the underwater vehicle detaches from the launch tube and starts its engine, the interaction between the tail cavity and the high-speed jet significantly impacts its motion stability and engine efficiency. Therefore, it is crucial to study the evolution mechanism of cavities in vertical motion. However, in traditional water tunnel experiments, the evolution of the cavity differs from the actual situation of vertical launch due to the influence of buoyancy. This study investigates the dynamics and motion trajectories of tail cavities and high-speed gas jets in the vertical movement of vehicles under different Froude numbers and nozzle stagnation pressure ratios through experimentation. The experimental results show two modes of tail cavity evolution: intact cavity (IC) and foam-conical cavity (FC-CC). Increasing the Froude numbers and stagnation pressure ratios facilitates the transition of the cavity from the IC mode to the FC-CC mode, effectively suppressing the formation and intensity of re-entrant jets, thereby reducing its impact on the bottom of the vehicle and enhancing motion stability. By deriving the formula for the length of the jet core area, it was found that the jet length is linearly related to the nozzle stagnation pressure, further revealing the mechanism of cavity evolution. These findings offer a new perspective for a deeper understanding and prediction of the dynamic behavior of underwater vehicles.</p></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141606280","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}

引用次数: 0

Model test of L-shaped caisson quay wall in sand foundation with clay interlayer 粘土夹层砂地基中 L 型沉箱码头墙的模型试验

IF 4.3 2区工程技术

Applied Ocean Research Pub Date : 2024-07-14 DOI: 10.1016/j.apor.2024.104128

{"title":"Model test of L-shaped caisson quay wall in sand foundation with clay interlayer","authors":"","doi":"10.1016/j.apor.2024.104128","DOIUrl":"10.1016/j.apor.2024.104128","url":null,"abstract":"<div><p>Laboratory model tests were conducted to investigate the stability of the L-shaped caisson quay wall installed on the sandy soil with clay interlayer. A total of three L-shaped caisson models were cast to explore the effects of the loading position and the position and thickness of the clay interlayer on their stability under plate loading. The ultimate bearing capacity of the L-shaped caisson quay wall on clay interlayer foundation was reduced by a maximum of 41 % compared to sand foundation. The ultimate bearing capacity was significantly reduced when the distance of the clay interlayer to the rubble mound was less than 1/5 of the quay wall height. The applied surcharge made the lateral earth pressure coefficient higher than the active earth pressure coefficients and triangularly distributed along the L-shaped caisson wall. The modified Beton's method considered the effect of the toe length of the L-shaped caisson could more accurately predict the lateral earth pressure. The failure of the L-shaped caisson quay wall on the clay interlayer foundation has three forms Type-I, Type-II, and Type-Ⅲ which are influenced by the loading position, L-shaped caisson dimensions, and positions of the clay interlayer.</p></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141623111","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}

引用次数: 0