Applied Ocean Research最新文献

{"title":"Model validation and improved PTO modeling of a field-deployed wave energy converter with tethered heave plate","authors":"David Okushemiya ,&nbsp;Curtis J. Rusch ,&nbsp;Bryson Robertson ,&nbsp;Zhe Zhang","doi":"10.1016/j.apor.2026.104921","DOIUrl":"10.1016/j.apor.2026.104921","url":null,"abstract":"<div><div>Rigorous incremental testing and validation are essential to advancing wave energy converter (WEC) technology. Although laboratory wave tank testing remains common, it poses challenges in scaling hydrodynamic responses and power take-off (PTO) dynamics. These issues are more pronounced for WECs with tethered heave plates due to complex interactions between the structure, tether, heave plate, and PTO; all of which often exceed tank depth and scaling limits. Field testing enables full-system evaluation but introduces practical limitations, including environmental variability, limited sensing, and measurement uncertainty. A knowledge gap remains in how to overcome these limitations to extract meaningful insights and validate WEC numerical models using field test data. Moreover, full-scale PTOs exhibit significant nonlinearities, such as generator inertia, internal losses, and inefficiencies across the full energy conversion chain, that are not captured in current PTO models. This highlights the need for improved modeling techniques to realistically estimate useful power and energy output. This study uses a field-deployed WEC with a tethered heave plate to demonstrate how combining statistical and spectral analyses enables comprehensive insight and validation of WEC models using field data. It also advances PTO modeling by incorporating generator inertia and fitting a parametric relationship between shaft speed and useful power based on PTO dynamometer test data. This approach predicted power and energy within 9% of field measurements, whereas conventional models overestimated these output by up to a factor of 3. The improved PTO modeling yields more realistic levelized cost of energy (LCOE) estimates to better guide future full-scale WEC development.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"166 ","pages":"Article 104921"},"PeriodicalIF":4.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921179","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}

{"title":"Numerical modelling of air-induced drag reduction allowing the transition between bubbly, air layer and mixed regimes","authors":"Benjamin Krull ,&nbsp;Kasper Bilde ,&nbsp;Christian Kringel ,&nbsp;Richard Meller ,&nbsp;Victor Molbak ,&nbsp;Georgios Papaioannou ,&nbsp;Fabian Schlegel ,&nbsp;Matej Tekavčič ,&nbsp;Filotas Tziaros","doi":"10.1016/j.apor.2025.104892","DOIUrl":"10.1016/j.apor.2025.104892","url":null,"abstract":"<div><div>Air lubrication can reduce the frictional resistance of ships, leading to significant fuel cost savings. However, the performance of air lubrication systems varies considerably, depending on the operating conditions. Complex gas morphologies play a crucial role here but are difficult to predict. Such a variety of morphologies (bubbly flow, air layers, or mixed regimes) requires morphology-adaptive methods, such as MultiMorph. This method allows for multiple morphologies of a given phase, including the transfer between them. The injection of gas can result in air bubbles, air layers, or a mixed regime, based on local transfer mechanisms. The ability to predict these morphologies is a distinctive feature of this method. Alternative methods prescribe a specific regime <em>a priori</em>, and do not allow a transition. To assess the suitability of MultiMorph for air lubrication problems, two geometries with different complexities are considered. The first test validates the method against flat plate experiments. Various water velocity and gas flow rate combinations were considered to investigate their influence on gas morphology and the associated drag reduction. The second case features a three-dimensional ship hull geometry with two bubble injectors to test the applicability of the method to a more complex scenario, including a curved geometry. The method performs well in both test cases and qualifies as a useful tool for numerical investigations of air lubrication phenomena.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"166 ","pages":"Article 104892"},"PeriodicalIF":4.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145734800","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}

{"title":"Physics-informed dimensionality reduction for propeller shape optimization","authors":"Stefano Gaggero ,&nbsp;Andrea Serani","doi":"10.1016/j.apor.2026.104932","DOIUrl":"10.1016/j.apor.2026.104932","url":null,"abstract":"<div><div>The design of marine propellers is challenged by high-dimensional parameter spaces and the need to balance efficiency with cavitation avoidance. Dimensionality reduction techniques offer a cost-effective way to address the curse of dimensionality, but geometry-based approaches such as parametric model embedding (PME) may neglect local features with strong hydrodynamic relevance. This work introduces the application of physics-informed PME (PI-PME) to propeller shape optimization, where physical observables, including pressure distributions and performance indicators, are embedded into the reduced-order space. A multi-objective optimization framework, based on boundary element method analyses and validated with Reynolds-averaged Navier–Stokes simulations, is applied to a cruise-ship propeller. Comparisons between original, PME-reduced, and PI-PME-reduced design spaces demonstrate that PI-PME preserves critical sectional features and significantly improves optimization results. The results highlight the benefits of integrating physical information into dimensionality reduction, enabling reliable, efficient, and physics-aware design optimization of marine propellers.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"166 ","pages":"Article 104932"},"PeriodicalIF":4.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972755","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}

{"title":"A reliability-prioritized adaptive real-time MBES data processing method for AUVs in complex environments","authors":"Jinyu Zhou,&nbsp;Toshihiro Maki","doi":"10.1016/j.apor.2025.104883","DOIUrl":"10.1016/j.apor.2025.104883","url":null,"abstract":"<div><div>With their advanced autonomous navigation capabilities, AUVs are highly effective tools for detecting and analyzing intricate underwater structures. The challenges associated with real-time manual control place significant demands on AUV intelligence, particularly in data processing and environmental understanding. To enhance AUVs’ capacity for thorough exploration and identification of complex underwater structures, this research aims to develop an adaptive approach for processing MBES data. Conventional MBES data processing methods are largely designed for post-processing or real-time processing under predefined conditions. However, these methods are insufficient for addressing the unpredictable and complex scenarios encountered during AUV surveys. To overcome these limitations, this paper presents a novel strategy for MBES data processing. At its core is an adaptive algorithm designed to suppress unreliable MBES data, optimized for handling complex 3D targets, combined with a customized approach for target surface reconstruction. The proposed method significantly enhances AUVs’ ability to process MBES data and analyze underwater target surfaces in real time, thereby advancing their capabilities for autonomous exploration.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"166 ","pages":"Article 104883"},"PeriodicalIF":4.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683697","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}

{"title":"Physics-informed online low-rank separation for weak target enhancement in rough seabed waveguides","authors":"Jie Pang ,&nbsp;Bo Gao ,&nbsp;Zhou Zhen ,&nbsp;Li Gongyun ,&nbsp;Zhuang Tianyi ,&nbsp;Yuan Shihai","doi":"10.1016/j.apor.2025.104881","DOIUrl":"10.1016/j.apor.2025.104881","url":null,"abstract":"<div><div>We address weak bottom-target feature enhancement under strong rough-seabed reverberation with a physics-informed, online delay-spectrum (DS) separation framework. A roughness-aware ray model reveals that, in the DS domain, the stationary propagating field is low-rank while target returns are sparse. We develop two streaming algorithms: DS-incremental singular value decomposition (DS-iSVD) for single-pass, low-latency updates, and DS-Grassmannian optimization (DS-GO) for iterative refinement. Scaled-tank experiments with scaling factor (SF) 1000, peak signal-to-interference ratio (SIR<span><math><msub><mrow></mrow><mrow><mtext>peak</mtext></mrow></msub></math></span>) <span><math><mrow><mo>−</mo><mn>20</mn><mo>.</mo><mn>9</mn></mrow></math></span> dB, and signal-to-noise ratio (SNR) 14.2 dB show that both methods demonstrate recovery of targets 20 dB below interference. DS-GO achieves mean SIR improvement <span><math><mi>Δ</mi></math></span>SIR <span><math><mrow><mo>≈</mo><mn>14</mn><mo>.</mo><mn>6</mn></mrow></math></span> dB and improves separation accuracy versus DS-iSVD: mean center offset distance (COD) decreases from 0.112 s to 0.092 s (<span><math><msub><mrow><mi>ℓ</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span>) and from 0.121 s to 0.100 s (<span><math><msub><mrow><mi>ℓ</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>); the mean 1-Wasserstein distance (W1) is 0.173 s. Monte Carlo (MC) SNR sweeps (0–10 dB) confirm robustness: DS-GO attains the best overall ridge score (RS), lowest W1 and COD, and highest peak hit rate (PHR) consistency with small variance, while DS-iSVD is a close second with the lowest latency. The approach enables real-time, physically interpretable feature enhancement for autonomous underwater vehicles (AUVs) and synthetic aperture sonar (SAS) in rough-bottom environments.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"166 ","pages":"Article 104881"},"PeriodicalIF":4.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683706","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}

{"title":"POD-Galerkin reduced-order modeling of the El Niño-Southern Oscillation (ENSO)","authors":"Yusuf Aydogdu ,&nbsp;Navaratnam Sri Namachchivaya","doi":"10.1016/j.apor.2025.104893","DOIUrl":"10.1016/j.apor.2025.104893","url":null,"abstract":"<div><div>Reduced-order modeling (ROM) aims to mitigate computational complexity by reducing the size of a high-dimensional state space. In this study, we demonstrate the efficiency, accuracy, and stability of proper orthogonal decomposition (POD)-Galerkin ROM when applied to the El Niño-Southern Oscillation model, which integrates coupled atmosphere, ocean, and sea surface temperature (SST) mechanisms in the equatorial Pacific. While POD identifies the most energetic modes of a system from simulation data, the Galerkin projection maps the governing equations onto these reduced modes to derive a simplified dynamical system. Leveraging the unique coupling properties of the model, we propose a novel approach to formulate a reduced-order model derived from Galerkin projection. Our approach achieves remarkable computational efficiency, requiring only four POD modes. The results provide highly stable and accurate solutions over 95% compared to the high-dimensional full-order model (FOM), highlighting the potential of POD-Galerkin reduction for efficient and accurate climate simulations.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"166 ","pages":"Article 104893"},"PeriodicalIF":4.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787732","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}

{"title":"The dominant role of jetting in micron- and sub-micron sea spray produced by bubble bursting: A revised model and comparison with measurements","authors":"Alfonso M. Gañán-Calvo ,&nbsp;Miguel A. Herrada ,&nbsp;José M. López-Herrera","doi":"10.1016/j.apor.2025.104891","DOIUrl":"10.1016/j.apor.2025.104891","url":null,"abstract":"<div><div>The size distribution of sub-micron sea spray aerosols (SSA) is a critical component of climate models, yet the primary physical mechanism governing their production – specifically the competition between film and jet droplets from bubble bursting – has remained a subject of intense debate. This work presents a revised, first-principles model to quantitatively resolve this controversy and demonstrate the dominance of jetting for producing micron and sub-micron aerosols. Our approach first rules out the film droplet mechanism as a primary contributor for this size range by demonstrating through physical scaling and numerical simulations that the final average ejected volume of sub-micron droplets is significantly smaller than that from jetting. We then construct a comprehensive global probability distribution function (PDF) for SSA by rigorously modeling its fundamental components in sequence: (i) refining the sub-surface bubble size distribution with a simpler and better experimentally supported exponential law, and (ii) deriving novel scaling laws for the number and size distribution of droplets per bursting event from a large set of high-resolution numerical simulations. A key finding is that the droplet size PDF from a single bubble follows a highly-skewed distribution – optimally modeled by a Generalized Inverse Gaussian distribution – revealing a prolific production of nanometric droplets previously unaccounted for by simpler models. When integrated, these components yield a final predictive model for the global SSA size distribution, with parameters derived directly from physical principles and simulations rather than empirical fitting. The model demonstrates strong predictive consistency, showing close qualitative agreement with a wide corpus of experimental data from both laboratory and oceanic measurements, particularly across the critical 25 nm to <span><math><mrow><mn>2</mn><mo>.</mo><mn>5</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> range. By clarifying that jetting is the dominant pathway and providing a robust, physically-grounded predictive tool, this research significantly enhances the fundamental understanding of marine aerosol generation and provides a more accurate foundation for climate and atmospheric chemistry models.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"166 ","pages":"Article 104891"},"PeriodicalIF":4.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145734798","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}

{"title":"Mitigating roll response of high-speed catamarans by dual Demihull mounted T-Foils, Part 1: Design and validation in calm water open-loop tests","authors":"Ehsan Javanmard ,&nbsp;Javad A. Mehr ,&nbsp;Michael R. Davis ,&nbsp;Damien S Holloway ,&nbsp;Jason Ali-Lavroff","doi":"10.1016/j.apor.2026.104922","DOIUrl":"10.1016/j.apor.2026.104922","url":null,"abstract":"<div><div>Efficient roll motion mitigation is essential for ensuring the structural integrity and passenger comfort of high-speed catamarans in oblique seas. Ride Control Systems (RCSs) used by Incat Tasmania wave-piercing catamarans (WPCs) typically consist of a single centrally mounted bow T-Foil and two stern-mounted trim tabs, and roll control relies solely on the independent action of the stern tabs, limiting their effectiveness for heave and pitch while not providing optimal ability to mitigate roll in beam and oblique seas. This study experimentally evaluates a new RCS that integrates dual demihull-mounted bow T-Foils with stern trim tabs. The system was implemented on a 2.5 m scale model of a 112 m Incat Tasmania WPC and tested in calm water at 2.89 m/s (equivalent to 37 knots full-scale) using open-loop step and frequency response experiments. Step response tests assessed heel responses under various demihull T-Foils and stern tab deflection patterns. The most effective heel excitation was achieved when the port and starboard demihull T-Foils and stern tab control surfaces operated in antiphase, increasing the heel range by about 43% compared to the centre bow mounted T-Foil RCS configuration. Frequency response tests demonstrated that the integration of dual T-Foils enhanced the RCS roll excitation capability by 45%. A lumped parameter approach was employed to derive and solve the roll dynamic equation of the model, which accurately predicted the heel responses observed in step response tests, with an average deviation of just 4.7%. It also predicted roll response and phase lag trends across a range of excitation frequencies, closely aligning with experimental trends. These findings highlight the significant improvement in the system’s roll control capability by incorporating demihull-mounted T-Foils into the RCS configuration, providing strong support for the new RCS design and laying the foundation for the development of a roll control algorithm for future closed-loop control experiments.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"166 ","pages":"Article 104922"},"PeriodicalIF":4.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972752","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}

{"title":"A Generative AI Model for irregular wave conditions that induce parametric roll","authors":"Kevin J. Maki ,&nbsp;Hyo-Jin Park ,&nbsp;Wenzhe Xu ,&nbsp;Bo Woo Nam","doi":"10.1016/j.apor.2026.104917","DOIUrl":"10.1016/j.apor.2026.104917","url":null,"abstract":"<div><div>Parametric roll is a nonlinear and intermittent dynamical phenomenon that causes damage to or loss of cargo, and poses significant risks for passenger safety and comfort. The current engineering practice to evaluate susceptibility or likelihood of parametric roll requires hours of nonlinear simulation or model tests in many wave conditions from the long-term operation wave scatter diagram. In this paper a novel generative AI method is proposed to learn the specific conditions that lead to parametric roll without the need to perform exhaustive and time consuming Monte Carlo simulations of all wave conditions. The method uses a low fidelity hydrodynamics model to generate the required large set of training data. A distillation process is employed that produces a series of models that can generate new wave conditions that lead to increasingly severe parametric roll behavior. Then the exceedance probabilities derived from the generated wave conditions are shown to closely match those from Monte Carlo simulations, while requiring significantly fewer computations. Finally, the generated wave conditions are verified by performing simulation with a weakly-nonlinear IRF method, confirming the ability of the method to find conditions that lead to pronounced parametric roll responses at a small fraction of the cost relative to the current practice of using Monte Carlo simulation.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"166 ","pages":"Article 104917"},"PeriodicalIF":4.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972750","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}

{"title":"Experimental investigation of suction-assisted penetration of compartmented bucket foundations","authors":"Linlong Mu ,&nbsp;Tao Zhou ,&nbsp;Yimin Lu ,&nbsp;Guangming Yu ,&nbsp;Jianguo Sun","doi":"10.1016/j.apor.2026.104923","DOIUrl":"10.1016/j.apor.2026.104923","url":null,"abstract":"<div><div>Compartmented bucket foundations (CBFs) represent a promising alternative to conventional offshore wind turbine foundations, offering enhanced structural stability and bearing capacity. However, the compartmented internal configuration of CBFs complicates the soil-water-structure interaction and poses unique challenges for suction-assisted installation, particularly in sandy soils where seepage effects are prominent. This study presents a series of model tests investigating the suction penetration behavior of both mono bucket foundations (MBFs) and CBFs in homogeneous sand. By varying bucket wall thickness, bulkhead thickness, and mid-chamber size, the influence of compartment geometry on penetration suction was evaluated. Results show that suction installation significantly reduces penetration resistance compared to jacking, which requires up to 8.7 times resistance for MBFs and 15.8 times for CBFs compared to suction-assisted penetration. Additionally, while increased wall and bulkhead thickness lead to higher suction demands, variations in mid-chamber size have minimal impact. Moreover, a theoretical model originally developed for MBFs was extended to incorporate additional bulkhead-induced resistance. The modified model provides accurate predictions for suction pressure, particularly during the stable penetration phase. This work advances the understanding of CBF installation mechanics and offers practical guidance for optimizing suction bucket designs in offshore wind applications.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"166 ","pages":"Article 104923"},"PeriodicalIF":4.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921078","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}