bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation on Flow-Induced Rotation of Coupled Double Cylinders Arranged in Tandem
Authors: Feng Weipeng , Yang Xu , Yan Xiang , Li Lingfan 
Published: August 2024

Abstract
The flow-induced rotation of coupled double cylinders in tandem has rarely been investigated in existing studies. In this paper, the theoretical basis of flow-induced rotation was established, the experimental setup was established and verified. Based on the test data, the flow-induced rotation characteristics of coupled double cylinders arranged in tandem were investigated. The study aims to provide reference for the design of the flow-induced vibration energy conversion equipment. The main conclusions can be summarized as follows: The oscillation response of coupled double cylinders arranged in tandem is vortex-induced vibration (VIV). When the spacing ratio of coupled double cylinders is 4.0, the amplitude is low and a “re-growth zone” is observed in the lower branch of VIV. When the spacing ratio is 6.0, the amplitude is high, and the maximum arc length ratio (A*) is 0.92. When the spacing ratio is 8.0, the lock-in range is wide. The effect of system stiffness (K) on flow-induced rotation response is not sensitive. The width of lock-in range is similar under different stiffness, while the desynchronization and the frequency response in the non-locked range are significantly different. The maximum arc length ratio is 0.98, which occurs at K = 1400N/m.
Laboratory Investigations on Oscillatory Seabed Responses and Scour Around a Pipeline Under Wave-Current Loading
Authors: Xu Yue , Cui Lin , Jeng Dong-Sheng , Sun Ke , Chen Bing 
Published: August 2024

Abstract
In this paper, a series of preliminary experimental data for wave (current)-induced hydrodynamics, pore-water pressure and scour around an exposed pipeline is presented. Unlike previous studies, the combined action of waves and currents is considered in this study. Wave flume experiments were conducted to investigate the temporal and spatial variations of pore-water pressures and seepage, as well as the development of scour around a pipeline. The experimental results indicate that the seabed response caused by the combined action of waves and currents are significantly different from those caused by wave load alone. It was found that the amplitudes of pore-water pressures increase, while the attenuation of pore-water pressures slows down under the large wave height with a large current. Additionally, the amplitude of seepage force under the combined action of wave and current is significantly greater than that under wave-only action, which subsequently affects the scour process around the pipeline. As the current velocity increases, the equilibrium scour depth increases, and the time to reach the equilibrium depth is also longer. Moreover, under the action of wave and current, the maximum scouring depth is more significantly affected by the high current velocity.
Experimental Investigation of Hybrid Smart Brine With Phosphate and Hexameta-Phosphate in Enhancing Oil Recovery From Carbonates
Authors: Murad Abdul Majid , Qi Chuangchuang , Haroun Mohamed , Al Kobaisi Mohammed , Rahman Md Motiur 
Published: August 2024

Abstract
Smart water flooding (SWF) has become an enhanced oil recovery (EOR) technique in field applications, as it provides better microscopic displacement efficiency in a relatively economic and environmentally friendly manner compared to other EOR techniques. The ionic composition, the key parameter that affects SWF performance in carbonates, has been extensively investigated to understand the EOR mechanism. The most widely accepted mechanism is that the ion exchange between injected brine and reservoir rock causes wettability alteration towards more water wet, leading to an improvement in oil recovery. Nevertheless, a consistent understanding and explanation of the geochemistry of how specific ions affect EOR performance has yet to emerge.
In this study, hybrid smart brine formulations were developed by spiking seawater with specific amounts of phosphate and hexametaphosphate (HMP) and their potential to increase oil recovery from carbonate core plugs were asseessed. Interfacial tension (IFT) measurements were performed for various smart brines with crude oil. In addition, brine compatibility analysis was conducted to study the potential of salt precipitation due to interactions between injected water and formation water, and the ability of the smart brines to create emulsions was assessed. A series of core flooding experiments was conducted to evaluate the ability of smart brines to increase oil recovery. Amott-Harvey/USBM wettability analysis was conducted to select smart brines and study their effect on wettability. Zeta potential measurements were conducted to capture the possible electric double-layer expansion.
It was concluded that excessive spiking with HMP led to precipitation and the optimal concentration was determined. Moreover, wettability analysis indicated that HMP is a stronger wettability modifying agent than phosphate, while phosphate performed better in reducing the IFT than HMP. Core flooding experiments demonstrated that creating a hybrid smart brine containing both phosphate and HMP has combined advantages. In addition, none of the studied smart brines generated an emulsion. Zeta potential measurements showed that flooded samples exhibited less negative values than aged samples, indicating the release of trapped oil. This study demonstrates the potential of increasing oil recovery from carbonate core plugs and can help to understand the impact of phosphate and HMP on EOR performance.
Numerical Hydrodynamic Investigations of a Multi-Pile-Supported Aquacultural Structure
Authors: Wang Hanbin , Zhang Xueyan , Zhang Xiantao , Li Xin , Tian Xinliang 
Published: August 2024

Abstract
With the continuous consumption of natural resources in the ocean, aquaculture has become a new focus in various countries and fish farming structures have developed rapidly in last decades in both nearshore and offshore regions. However, the hydrodynamic characteristics of structures which integrated aquacultural nets and other marine structures together remain unclear. Monopile-based structures are common types of fixed-bottom structures at offshore sea areas with shallow water depths where are rich in wind energy, oil and fishery resources. In order to improve the utilization efficiency of offshore structures, a multi-pile-supported aquacultural structure is proposed in the study which consists of net panels and monopiles. In this paper, a new coupling method which combined discrete-module-beam (DMB) method and lumped mass method with Screen model is proposed to obtain the hydrodynamic responses of monopiles and nets in the integrated aquacultural structure. A series of numerical calculations are carried out to investigate the hydrodynamic characteristics of pile-net structures under different regular wave conditions. The influence of net panels on the hydrodynamic characteristics of monopiles are measured and discussed. It is found that the influence of net panels on the hydrodynamic characteristics of current model is negligible. Overall, the results of this study can be used as a basis for future design and optimization of similar integrated marine structures.
Laboratory Experiments on Statistics of Shoaling Finite Amplitude Waves
Authors: Mendes Saulo , He Yuchen , Chauhan Kapil , Chabchoub Amin , Kasparian Jérôme 
Published: August 2024

Abstract
The formation, growth and increase in the frequency of extreme waves over the coast has been consistently observed and reproduced in laboratory experiments in recent years. On the other hand, as soon as waves reach the surfzone, a new regime comes into play where sub-Gaussian wave statistics dominate, as described by Glukhovskiy-type of height distributions. Dealing with a wave field transitioning from steady-state to out-of-equilibrium conditions due to a steep shoal, available theories can model the rogue wave amplification near shallow water regimes before the surf zone. Nevertheless, theoretical work to date has also been limited to small amplitude waves, thus, far from a wave breaking regime. To connect these two regimes (prior to and post the surf zone), we experimentally probe inhomogeneous finite amplitude wave fields that overlap both.
Hydrodynamic Forces for HVDC Cable Bundles Under Wave and Steady Current Conditions
Authors: Griffiths Terry , Pretorius Joshua , Tong Feifei , An Hongwei , Draper Scott , Riverola Calavia Javier , Ledoux Bart , Pistani Fabrizio 
Published: August 2024

Abstract
A collaborative study between The University of Western Australia (UWA), Southern Cross University (SCU), Aurora Offshore Engineering (AOE) and Jan de Nul (JDN) was undertaken to investigate the hydrodynamic forces experienced by a single cable and cable bundle at various angular orientations under steady and oscillatory flow conditions. Physical model testing was undertaken at the UWA Large O-Tube (LOT) Facility, which is located at UWA’s Coastal Ocean Research Laboratories (CORL). This testing was conducted at 1:1 scale, with the capacity of the O-Tube able to replicate flow conditions relevant for design. Computational Fluid Dynamics (CFD) modelling was undertaken to complement the physical testing and aid in interpretation of the results, including flow visualization and accounting for the effects of flow blockage in the water flume.
These test results represent novel contributions to the understanding of hydrodynamic forces for HVDC single pipe and bundle configurations accounting for the influence of a number of critical flow parameters, including Reynolds number (current velocity), Keulegan-Carpenter number (wave characteristics), surface roughness (pipe features), incoming turbulence intensity and bundle orientation. It is anticipated that these improvements in understanding contribute very helpfully to improving the safe workable range of metocean conditions in which these cables may be installed, lowering the risks of cable damage and improving the costs of installing the cables.
Annular Fluid Forces Generated by a Non-Newtonian Fluid With Variable Flowrate and Non-Uniform Rotational Pipe Movement
Authors: Cayeux Eric 
Published: August 2024

Abstract
In drilling operations, the precise estimation of annular fluid forces on a pipe is important to determine the drill-string movement in dynamic conditions. Yet, drilling fluids have a complex rheological behavior, and the inner pipe is usually eccentric and rotates. The pipe movement is usually non-uniform like for example when there are torsional stick-slips. Furthermore, the flow of liquid in the annulus is usually unsteady either because of pump acceleration or because of the axial pipe movement. With all these non-uniform movements of the inner pipe geometrical boundary and the accelerated flow of the fluid itself, it is unclear what is the hydraulic force applied by the fluid on the exterior of the pipe. A relationship that links the pipe movement to the total hydraulic force is derived. However, the total hydraulic force applies to both the wellbore and the pipe, and it is not evident in which proportion the total hydraulic force contributes to the hydraulic force on the pipe. To address this problem, computational fluid dynamic simulations are run to estimate the hydraulic force on a pipe subject to dynamic flow and pipe rotation conditions. It is found that even though the total hydraulic force varies substantially due to the dynamic boundary conditions, the proportion of the force that applies to the pipe varies in a much lesser extent. This proportion is compared to theoretical value corresponding to Newtonian fluids in steady-state conditions. It is found that the proportion is a linear function of the proportion for Newtonian fluids.
The Importance of Local Hydroelastic Effects When Calculating Structural Response From Measured Wave Slamming Pressures
Authors: Abrahamsen Bjørn Christian , Holstad Anders , Hellan Øyvind 
Published: August 2024

Abstract
The effect of hydroelasticity on local structural response due to measured wave impact loads are discussed. The structure considered are the vertical beams at the upper flare of a SEVAN SSP FPSO. The first method uses a modal method with uniform and constant added mass. The accuracy of this type of calculation is investigated through comparisons with a complete hydroelastic calculation. These hydroelastic calculations account for the load modifications due to the structural response in a consistent manner. This means that the added mass is time dependent and the effect of slam damping is included. As the load modifications due to the structural deformation is primarily a dynamic effect, the effect of hydroelasticity is discussed through dynamic amplification factors (DAF). The analyses show that the calculated DAFs relevant for the measured wave slamming loads are in a range where the simplified method using only uniform and constant added mass overestimates the structural response considerably in most cases. As an example, the responses from the simplified calculations are in the range of 30 to 40% higher than the response from the fully hydroelastic calculations for the two wave slams with the highest pressures.
A Calibrated Service Life Wear Model for the Pressure Armor Layer in Unbonded Flexible Pipes
Authors: Nielsen Christian Bergenstof , Christiansen Mads Peter , Gupta Abhishek , Juul Nicolai Ytterdal , Dhar Somrita , Pedersen Tommy 
Published: August 2024

Abstract
An important design driver of an unbonded flexible pipe is often the fatigue life of the tensile armor layers. However, in pursuit of providing the market with durable, high-spec flexible pipe structures suited for increasingly higher operating bore pressures, it has also been found that the wear of the pressure armor layer should also be understood and quantified to assess the service life of a flexible pipe.
This paper presents a novel approach to getting a direct coupling between the full-scale modeling of the flexible pipe and the wear of the pressure armor. This was done by measuring the wear of pressure armor samples extracted from an in-plane bending test portfolio. In this way, it has been possible to correlate the wear level to a large range of loads, pipe diameters, steel grades, and pressure armor geometries.
These measurements, combined with other details of full- and small-scale tests, have made it possible to develop a calibrated model that assesses the wear in the pressure armor layer. In this manner, it is now possible to quantify the wear in service conditions and use it to establish the influence on the service life.
The originality in this work is twofold: Based on wear measurements on pressure armor wires extracted from full-scale specimens, the wear rate in the pressure armor layer is shown to scale with slip amplitude. This phenomenon is known generally but has not been reported earlier for the unbonded flexible pipe. Further, the wear data from full-scale test specimens has been used to produce a calibrated model.
Even though the failure mode in the pressure armor has shown to be rare, it is important to include the relevant phenomenon in the model as pressures increase.
Simulation-Based Analysis of Parametric Rolling in Head Sea Conditions
Authors: Agrahri Gangesh Kumar , Somayajula Abhilash 
Published: August 2024

Abstract
This paper focuses on a significant maritime challenge, investigating the dangerous phenomenon called parametric rolling in KRISO Container Ships (KCS) using advanced numerical methods. The publicly available data from KCS serves as a valuable benchmark for study. The study highlights the benefits of employing numerical simulations, which provide a cost-effective and controlled approach to understanding complex non-linear phenomena like parametric rolling. The research highlights how fine hull structure, pronounced bow flare and flat transom stern in Container Ships make them particularly vulnerable to this phenomenon. The study employs a time-domain nonlinear simulation tool (HydRA - Hydrodyanamics Response Amplitude) with six degrees of freedom to simulate the ship’s motion nearly accurately. The tool effectively integrates linear radiation and scattering forces from the frequency domain program while handling the non-linear aspects of incident, restoring, and inertial forces. Comprehensive testing of the simulation tool against the head sea (at zero speed) conditions contributing to parametric rolling confirms its close approximation of parametric roll behaviour. This thorough study notably advances the safety of container ships and their crews by offering a more profound comprehension of the complex dynamics associated with parametric rolling and the crucial elements that impact its occurrence. The knowledge derived from this research is vital in refining ship designs and establishing effective measures to mitigate the risks associated with parametric rolling.
Down-Scale Wave Hydrodynamic Analysis for Marine Structures - the NORA-SARAH Approach
Authors: Wang Widar Weizhi , Christakos Konstantinos , Pákozdi Csaba , Bihs Hans 
Published: August 2024

Abstract
In a simulation-based and data-driven engineering approach, open-access met-ocean data sets and open-source simulation tools are critical elements for marine structure designs. In this work, the authors propose a combined approach for down-scale numerical modelling from offshore met-ocean data to wave loads on structures. The large-scale hind-cast database NORA3 and NORA10 from the Norwegian Meteorology Institute (MET) are used as offshore inputs. The open-source spectral wave model SWAN is used to simulate offshore waves in combination with local wind forcing. The spectral modelling results are then used as inputs in the open-source hydrodynamics framework REEF3D. Its fully nonlinear potential flow (FNPF) module REEF3D::FNPF is used for phase-resolving coastal wave propagation and nonlinear transformation simulations. The arbitrary Eulerian-Lagrangian (ALE) method is integrated into the FNPF model for highly efficient multi-body farm-scale force calculations and extreme events identifications. The extreme events are then closely examined using the hydrodynamic coupling (HDC) approach by transferring the flow kinematics from REEF3D::FNPF to the high-fidelity computational fluid dynamics (CFD) model REEF3D::CFD for fluid-structure interaction analysis. The down-scale approach using the open-access met-ocean data NORA3 and open-source numerical tools and techniques SWAN-REEF3D-ALE-HDC (SARAH) leads to the open and efficient preliminary and detailed design procedure: the NORA-SARAH procedure. This article elaborates on the procedure and demonstrates its effectiveness with an example of a navigational signal tower assessment on the Norwegian coast.
Wave Diffraction and Radiation From a Floating Platform With a Moonpool Array
Authors: Zhou Yao , Zhao Xuanlie , Geng Jing , Guedes Soares C. 
Published: August 2024

Abstract
Floating platforms equipped with multiple moonpools offer tremendous potential for applications in advanced offshore aquaculture. This paper investigates the hydrodynamics of a floating platform equipped with multiple moonpools, highlighting their promising applications in advanced offshore aquaculture. Utilizing an in-house linear potential-flow solver, a thorough analysis of a floating platform integrated with an array of moonpools is conducted. The investigation includes a detailed comparative study on the hydrodynamic behaviour of platforms with and without moonpools, providing the physical explanations governing the observed distinctions. Additionally, we explore wave resonance phenomena within the moonpools and the impact of the configurations on the resonance behaviour is illustrated.
Numerical Simulation and Evaluation Analysis of Ship Tunnel Passage Schemes Under Complex Waterway Conditions
Authors: Lian Zhengchen , Wang Lizheng 
Published: August 2024

Abstract
Under the current trend of green development of ships, the technical requirements of ship types should fully reflect the level of green development of ship types. Meanwhile, the adaptability assessment between ships and complex waterways is also an important manifestation of ship operation efficiency. This article focuses on the environmental characteristics of the complex navigation channel in the Three Gorges Dam, and designs a tunnel passage mode using electric propulsion (towing) wheels. Specifically, by designing the overall plan and using STAR-CCM software for numerical simulation calculation of electric propulsion wheel passing through tunnels, and designing the power scheme of electric propulsion wheel, to ensure the safe, green, and efficient passage of ships passing through complex waterways. Furthermore, evaluation indicators are selected for this design scheme, and the AHP-VIKOR evaluation model is used to solve the evaluation problem of ship power push operation mode in the navigation tunnel of the Three Gorges New Channel under uncertain conditions. Finally, it can be concluded that, under the premise of engineering conditions and acceptable costs, for environmental considerations, the use of ship pushing method can be considered in the Three Gorges Navigation Tunnel. It is recommended that the pushing speed of the ship in the navigation tunnel should not exceed 2.5m/s, and the pushing auxiliary system should be equipped with 5–6 sets in one direction, 10–12 sets in the system, and at least one spare pushing wheel should be equipped; At the same time, it is necessary to consider adding corresponding intelligent navigation devices and strengthening security management to improve the security of the top push method.
Case Studies of BEM Solver Accuracy With the Open-Source Code Capytaine
Authors: Ancellin Matthieu , Nguyen Nhu 
Published: August 2024

Abstract
Capytaine is an open-source Python-based Boundary Element Method (BEM) program designed to simulate wave-structure interactions employing linear potential flow theory in frequency domain. A long term work is currently underway to improve its performance and accuracy, which is behind its commercial counterparts. The present paper focuses on two steps of the numerical resolution: the choice between the direct and indirect boundary integral equation and the accuracy of the tabulation used as surrogate model of the Green function. The results are illustrated on two test cases for which issues had been previously reported, namely the floating cylinder with a thin heave plate and the DeepCWind floating offshore wind turbine platform reference model. The inaccuracy of previous versions of Capytaine on these two test cases is explained and new results are presented in comparison with WAMIT and HAMS.
Investigation of Structural Anomaly Reported at Top Section of Flexible Riser
Authors: Pasqualino Ilson Paranhos , Duarte Ribeiro Rodrigo , de Carvalho Pinheiro Bianca 
Published: August 2024

Abstract
The present study aims to carry out a structural analysis of an anomaly found in a 14-inch flexible riser, used to transfer natural gas from an FSRU unit (Floating Storage Regasification Unit) to a thermoelectric plant, located close to the Brazilian coast. The work aims to carry out global and local numerical-structural analysis of the riser, using data obtained from riser design and from a riser sample taken from a similar structure. As a result of the project, we seek to understand the cause of the anomaly found during visual survey and evaluate the permissible operating conditions, avoiding the worsening of the anomaly and a possible, but unlikely, failure. The work included data collecting from available design documentation, sample dissection to gather riser layers geometry, the development of a numerical model for global analysis to verify loading conditions to be used in the detailed local model, the development of a numerical model to simulate riser layers in other to reproduce expected responses. The finite element model detailed the internal carcass, the pressure barrier, and the internal pressure armor. The paper concluded that the anomaly is a result of the operational loads and that there is no risk of failure or leakage.