bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arrangement Effects on Flow Through an Array of Cylinders
Authors: He Fei , An Hongwei , Draper Scott , Ghisalberti Marco , Branson Paul , Cheng Liang 
Published: August 2024

Abstract
Although elements in natural and engineered systems, such as patches of aquatic vegetation, groups of pile foundations, and arrays of tidal stream turbines, are arranged in uniform or random configurations, there is a lack of understanding of hydrodynamic differences between these two arrangements. This paper presents results from two-dimensional direct numerical simulations of flow through a circular array of cylinders that have been undertaken to examine the hydrodynamic differences. It is shown that a random array has higher average drag coefficient and lower spatially averaged velocity within the array than these of a uniform array with the same diameter ratio. The lower drag coefficient for the uniform array is associated with the formation of characteristic flow structures, including two-row structure and shear layer reattachment and channelized flow in between adjacent lines of cylinders. As increasing perturbation of the array, these characteristic flow structures and the channelized flow progressively break down and hence the average drag coefficient increases and the spatially averaged velocity decreases. This paper provides guidelines for optimizing hydrodynamics of obstacle arrays through altering arrangement in real systems.
Analysis of Static, Dynamic, Global, and Local Load Effects for Ultimate Limit State Assessment of Semi-Submersible Hulls of Floating Wind Turbines
Authors: Wang Shuaishuai , Moan Torgeir , Gao Shan , Li Wei , Gao Zhen 
Published: August 2024

Abstract
Very limited research has been conducted on structural load effect analysis and design checks of large semi-submersible floating wind turbines (FWTs). Determining the combined static, dynamic, global, and local load effects in FWT is essential for the ultimate limit state (ULS) assessment of the floaters. This paper deals with the complex structural load effects for ULS analysis of column structures of a 10-MW semi-submersible FWT. First, a multi-body numerical modeling approach is employed to develop the floater model in a fully coupled FWT system to capture the time domain internal loads of column cross-sections under wind and wave conditions. Then, a high-fidelity approach and a simplified approach are developed to estimate lateral pressures on columns. With the obtained global cross-sectional loads and the corresponding lateral pressure, the ULS design check considering buckling for hull panels are performed for representative load cases. Detailed analysis results are presented and discussed, including perspectives of permanent and environmental load effects, as well as global and local lateral pressure load effects for buckling analysis of column structures. Moreover, comparisons of lateral pressures estimated by the high-fidelity and simplified approaches for buckling assessment of the outer column are made. Finally, the main conclusions are summarized. This study shed light on the importance of different structural load effects on ULS design checks. In addition, the simplified approach for lateral pressure estimate can be well used in the preliminary design stage of floaters to save large computational costs while obtaining acceptable results.
Immiscible Displacement of Oil by Water: An Experimental Investigation
Authors: Lund Bjørnar , Taghipour Ali , Saasen Arild , Ytrehus Jan David 
Published: August 2024

Abstract
Deviated well sections are common in modern well construction. In mature areas like the North Sea region, practically all producers or injector wells will have highly deviated sections. These wells must be completed in an optimal manner especially with respect to annular barrier integrity. The zonal isolation is important through all stages of the well’s life cycle. Since all wells must be permanently plugged before abandonment it is vital to ensure that annular barriers are designed with a long-term perspective and not only to minimize construction time and cost. Controlled laboratory environments with various fluid compositions and flow parameters are important to develop, validate and improve models and practices. Laboratory testing may often require significant simplifications to fit available resources, premises etc. and will not always be optimally designed to match relevant practical operations. Cement displacement is the objective for many such studies, while due to selection of fluids, in reality casing cleaning operations are investigated.
Most laboratory-scale experiments are conducted with water-based fluids for both the displaced and the displacing fluid. However, during cementing and clean-out operations the fluids are commonly immiscible, i.e. one fluid is water-based and the other fluid is oil-based. As a consequence, effects like immiscibility and wettability are important and will play a role for the displacement process.
We present results from displacement experiments where oil-based fluids are displaced by water-based fluids. Four experiment series were conducted. In the first series a commercial base oil was displaced by tap water with 3% NaCl. In the other three experiment series a real oil-based drilling fluid was displaced with three different brines with different viscosities and densities.
The experiments have been performed in a flow loop that consists of a 10 meters long test section with 5″ OD transparent pipe inside a 6,5″ transparent pipe. We investigate the effects of flow rate, string rotation speed, wellbore inclination, wellbore eccentricity and fluid properties on the displacement process. The displacement front is tracked using video recordings and electrical conductivity probes. Differential pressure and temperature transient measurements provide data which give additional information about the displacement process. The data can be used for validation of simulators as well as for designing cementing and wellbore cleanout operations.
Experimental Study on Added Resistance in Waves of KLNG at Design Speed and Low Speed
Authors: Kwon Yong-Ju , Park Dong-Min , Nam Bo Woo 
Published: August 2024

Abstract
In this study, experimental investigations were conducted to estimate the added resistance of KLNG in regular and irregular waves, with a specific focus on the effects of ship speed. A series of model tests were performed in ocean engineering basin of KRISO. The test model, with a scale ratio of 1:69, was towed with a soft spring in a diamond shape and two-axis load cells to measure the added resistance. Experimental conditions were established to examine the added resistance under various wavelength ratios and two ship speed conditions. At the design speed condition, it was found that the added resistance in waves exhibited peak values within the radiation dominant region, while under the low-speed condition, diffraction became more crucial to the added resistance. Additionally, a high correlation was found between added resistance and relative wave motion responses of bow sections. In irregular waves, a discussion was made on a comparison between the results obtained by the direct and spectral methods.
Integration of a Novel Wave Power Generator Into Vehicle Charging System
Authors: Alawur Hadeel , Alkuhily Njood , Mutawakkil Sadil , Zayane Chadia 
Published: August 2024

Abstract
This paper emphasizes the potential role of electric vehicles (EVs) in reducing carbon footprints. It introduces the “Mauja” wave energy conversion device, designed to harness ocean wave energy for EV charging. The system integrates a multi-panel flap and a rotary generator, directing generated electricity to charge EVs through control electronics. Utilizing SOLIDWORKS, ANSYS AQWA, and WEC-Sim, the study explores the Mauja device’s technical design, fluid dynamics, and simulations under various wave conditions. It investigates the impact of factors like device dimensions, inertia, and wave types on power absorption, highlighting the device’s adaptability to different waves. The research underscores the importance of design in optimizing power absorption from ocean waves. Ultimately, this study emphasizes the significance of innovative wave energy conversion systems in mitigating CO2 emissions and highlights the need for adaptable designs to effectively utilize ocean wave energy for sustainable power generation and EV charging.
CFD Simulation of Hydrodynamic Interaction Between a Ship and a Podded Propeller Using Body Force Method
Authors: Seo Dong Cheol , Jahra Fatima , Wang Jungyong 
Published: August 2024

Abstract
This paper presents an application example of the body force propeller method to consider hydrodynamic interaction between the hull, pod and propeller blades; and predict the overall propulsion performance without implementing the actual rotating propeller model. As a test case, a tugboat with twin puller-pod units is selected, and a series of simulations, from a stand-alone propeller operation to a fully equipped hull under propeller overload conditions, are conducted. To evaluate the simulation performance improvement, two different modelling options in the body force propeller model, inflow sampling and induced velocity correction, are investigated. The estimated thrust, torque and tow force are then compared with the model test results. Finally, it is proposed to adopt the varying inflow sampling technique to enhance the simulation accuracies of the body force propeller method, particularly for propeller overload test cases.
Analysis of Nonlinear Hydrodynamic Properties of Shallow-Draft Floating Photovoltaic Structure
Authors: Cao Hangyu , Du Junfeng , Zhao Shujie , Zhang Deqing , Chang Anteng 
Published: August 2024

Abstract
As the global energy industry evolves and renewable energy rapidly advances, offshore floating photovoltaic (FPV) technology is garnering increasing attention. Unlike conventional water surface FPVs, ocean-based FPVs exhibit a more complex dynamic response to wave action. Traditional approaches, such as linear restoring stiffness and linear wave excitation forces used in marine structures, may not accurate for dynamic response prediction of FPVs due to their significant instantaneous wet surface changes attributed to their light weight, large span, and shallow draft. This research focuses on a novel type of shallow draft offshore photovoltaic floating structure, examining the variation of nonlinear restoring force in the FPV module under different offsets by an inhouse code. Additionally, the variation of the Froude-Krylov force on the FPV module in response to instantaneous changes in the wet surface area is explored. This investigation is crucial for understanding and optimizing the performance and design of such innovative floating photovoltaic systems.
Hydrodynamic Analysis of the Side-by-Side Moored FLNG-LNGC System
Authors: Di Shang , Ju Fan , Chen Tianwen 
Published: August 2024

Abstract
Considering the mooring systems, second-order wave forces and potential nonlinear gap resonance, the intricate relative motions between Floating Liquefied Natural Gas (FLNG) and Liquified Natural Gas Carrier (LNGC) during the offloading operation of Liquified Natural Gas (LNG) significantly increase the risk of collision. The present research mainly focuses on the numerical analysis of the forces of the side-by-side offloading system. Based on the three-dimensional potential theory modified by the Damping Lid Method, hydrodynamic coefficients such as the added mass, the quadratic transfer function (QTF) of drift forces and so on in the frequency domain are calculated. The Damping Lid is added to the free surface to suppress the overestimated wave elevation between two floating bodies in the close proximity. Using the Frequency to Time-Domain Transformation Method, the time-domain simulation can then be performed, through which the forces and the relative motions are subsequently obtained. The numerical calculation results indicate that if the incident wave frequency is close to the resonant frequency of the gap, a violent resonance phenomenon will occur in the liquid surface motion. Similarly, when the frequency of the low-frequency drift force is close to the natural frequency of the system’s horizontal movement, it can also cause resonance. The hydrodynamic coefficients and the motions of the side-by-side system, as well as the tensions of the mooring system, exhibit significant variations near both types of resonance frequencies.
Estimation and Experimental Validation of Extreme Waves and Loads on a Large Monopile
Authors: Pakozdi Csaba , Alsos Hagbart S. , Ravinthrakumar Senthuran , Nyboe Synne , Rolland Louise Ankerstjerne , Nordheim Knut 
Published: August 2024

Abstract
Numerical wave analyses of extreme sea states have been performed for a large monopile subjected to 50 year and 500 year hurricane conditions. The numerical analyses have been established using the REEF3D::FNPF software. The wave kinematics has then been combined with a Morison type load model containing a modified inertia term, KC dependent drag and a Weynberg-Campbell slamming term. The line loads generated from the numerical hydrodynamic analyses are then implemented into the SIMA FE solver to establish the extreme WTG responses.
The extreme statistics of hydrodynamic and structural response has been investigated and compared with results from model tests. The model test data sample is considerable and consist of 20 × 3h series of seed variations, including variations between sea states and mudline boundary conditions. When evaluating parameters such as crest height, steepness, we observe that the numerical wave tank approach allows for similar extreme behaviour as the observed in model tests.
In general, the numerical and experimental results agree well when comparing the extreme statistics. Beyond this, we also compare the extreme events in the slamming zone. This implies that we sequence the max. load events for both experiments and numerical analyses and sort them by magnitude before making a direct time domain comparison of each of the sorted extreme events. The correspondence between model tests and numerics for the splash zone loads, is also observed for the overall response statistics.
Finally, we conduct a comparison of waves between the REEF3D::FNPF-based models and more conventional constrained wave methods as outlined in IEC61400-3-1.
FIV Assessment of Piping Systems Using Vibration Screening and Advanced Analysis Methodologies
Authors: Skarlas Panagiotis , Ibrahimi Deborah , Varelis George E. , Peng Deng-Jr 
Published: August 2024

Abstract
Structural vibrations of piping systems due to internal fluid flow are common when the system contains flow domain variations, such as elbows, tee-joints, control valves, small bore connections and reducers. In this paper, the applicability of the Likelihood of Failure (LOF) screening methodology, as proposed by the Energy Institute (EI) guidelines, is investigated for a water injection piping system with complex geometry. The system comprises 16″–18″ piping and a manifold that distributes the flow to seven 6″ risers. The system flow rates were checked against the EI guidelines, resulting in a sub-critical LOF (≤ 0.5).
A combination of computational fluid dynamics (CFD) and finite element (FE) analyses in ANSYS Workbench software package is also employed for the assessment of the flow-induced vibrations (FIV) of the piping system, considering 1-way fluid-structure interaction (FSI) effects. The resulting pipe vibrations are post-processed to assess their acceptability in the Velocity RMS – Frequency domain, according to the EI methodology. FIV-induced stresses and fatigue damage are also assessed against structural limits.
For both models, the flowrates corresponding to sub-critical conditions (LOF ≤ 0.5) cause vibrations that fall into the problematic zone according to the EI Vibration Assessment methodology, and they result in a low fatigue life. Alternative support configurations are analysed, aiming at rectifying the system response in terms of vibrations and fatigue performance.
The results presented in this work indicate that even though the LOF screening is widely used for efficiently assessing the flow capacity of piping systems for safe operation, for systems with complex geometries the LOF screening may not be sufficient to ensure no FIV failures will take place. In such cases it is recommended that the assessment should be complemented with more advanced CFD/FE analyses.
Sensitivity of Ship Voyage Optimizations to Various Energy Cost Models
Authors: Chen Yuhan , Mao Wengang 
Published: August 2024

Abstract
A ship’s energy performance model describing the relationship between ship speed and energy consumption is an essential component in her voyage optimization system, since it is required to evaluate the energy costs associated with different voyage plannings. For energy-efficient voyage planning, such a ship model estimates the corresponding energy consumption of each feasible route/sub-route based on her sailing speeds and encountering environmental conditions. Thus, the reliability of a ship’s energy performance model is expected to have a great influence on the ship’s voyage optimization results. Various approaches have been widely researched to construct the ship performance model, such as empirical white-box models based on experimental tests and physical knowledge, data-driven black-box models using machine learning methods, and gray-box models combining the above two approaches, etc. In addition, various energy cost functions are used for the ship voyage optimizations, such as the total power or fuel consumption, etc. The objective of this study is to investigate the sensitivity of ship voyage optimizations due to different energy cost functions from different modeling techniques. A chemical tanker with full-scale measurement is used in the case study to study the sensitivity of voyage optimizations in terms of energy efficiency. Some insights into employing different energy cost functions and models are discussed in detail to provide good recommendation practices for optimal voyage planning.
Composite Repair of Corroded Pipelines
Authors: Takahashi Goes Tami , Drumond Geovana , Pinheiro Bianca , Pasqualino Ilson 
Published: August 2024

Abstract
Recent studies have demonstrated that composite materials can be used with practicality, agility, economy, and effectiveness in the execution of repairs of corroded steel tubes. Thus, the present work aims to study the behavior of metallic pipes repaired with composite materials manufactured in polymeric matrix reinforced by glass fibers submitted to internal pressure tests. For this, an externally corroded pipe was modeled in software Abaqus with a 50% reduction of the wall and repaired with composite material. The repaired pipe was submitted to internal pressure and the burst pressure was compared with experimental results from literature with an error of 3%. The numerical-experimental correlation validated the numerical model, which can be used with reliability and safety by industry.
Modeling Thermal-Hydrological-Mechanical (THM) Processes for CO2 Sequestration in Depleted Gas Reservoirs
Authors: Zhao Xinrui , Winterfeld Philip , Wu Yu-Shu 
Published: August 2024

Abstract
Over the past two decades, researchers have devoted enormous efforts into developing numerical models for simulating CO2 geo-sequestrations. Due to the large temporal and spatial scales associated with such processes, numerical modeling has proven to be the most cost-effective to evaluate them. Presently, the majority of the existing models were developed for CO2 sequestration in saline aquifers. In contrast, the number of models for depleted gas reservoirs is relatively small, and only a fraction of them have the capability to consider geomechanical and thermal coupling or complicated natural gas compositions.CO2 sequestration in depleted gas reservoirs is considered a promising technique for combating global warming. The use of depleted gas reservoirs has several advantages over saline aquifers, such as the availability of existing facilities and the proven capacity and stability of gas storage. It is believed that storing CO2 in depleted petroleum reservoirs can serve as an interim solution for storage until large-scale storage in saline aquifers reaches maturity. Here we propose an Equation of State (EOS) module for CO2 sequestration in depleted gas reservoirs or CO2-enhanced gas recovery. It takes into consideration the mutual solubilities in the CO2-hydrocarbon gas-brine system based on the equality of the chemical potentials of the aqueous and non-aqueous phases. In such a way, it can properly address CO2 dissolution into brine when hydrocarbon gas is present. Hydrocarbon gas includes methane, ethane, and propane. It employs well-recognized approaches to calculate the thermodynamic properties of the gaseous and aqueous phases. This EOS module has been applied to our in-house simulator, TOUGH2-CSM, to enable thermalhydrological-mechanical modeling. Our research could fill the gap and provide a reference for future studies in this regard.
Level Ice-Structure Interaction Simulations Using Solid and Shell Elements
Authors: Körgesaar Mihkel , Tabri Kristjan , Avi Eero 
Published: August 2024

Abstract
This article contributes to the design of ice-going vessels by presenting computationally efficient simulations of a rigid ship crossing level ice field for ice resistance estimation. First, the ice material model is calibrated against the existing four-point bending (4PB) experiments conducted in the Baltic Sea. The ice beam is modelled both with detailed solid and coarse continuum shell elements. Solid element simulations are used to verify the accuracy of the coarse shell modeling approach. Mesh size sensitivity of the shell element solutions is presented. Using the calibrated model the ice resistance of a passenger ferry operating in the Baltic Sea is assessed. Ice is modelled both with solid and shell elements to compare the differences in response. While solid model results provide a more realistic estimate of the ice forces, shell element simulations are 5 times faster. However, shell element results give about 20% lower load and thus can be less conservative, thus further calibration of model could be beneficial.
Multi-Objective Ship Voyage Optimization Framework for Underwater Noise Emission
Authors: Venkateshwaran Akash , Deo Indu Kant , Jaiman Rajeev K. , Jelovica Jasmin 
Published: August 2024

Abstract
Anthropogenic noise from marine shipping and other sources poses a serious threat to marine mammals and the ocean ecosystem. This paper aims to enhance a ship’s adaptability to varying ocean conditions, with the primary objective of reducing its contribution to underwater radiated noise (URN) along with fuel consumption. A new multi-objective optimization framework (MOOF) is developed that optimizes the ship’s sailing speed using a non-dominated sorting genetic algorithm (NSGA-II) to mitigate URN. Two objective functions: i) total noise intensity levels and ii) total fuel consumption are minimized under some voyage constraints. Subsequently, the Pareto solutions obtained from NSGA-II are further processed using a Euclidean-based multiple-criteria decision-making method to find the trade-off solution. To illustrate the efficacy of the MOOF, we consider a practical case study of a 6900 TEU containership in a voyage scenario. The proposed framework has shown a 94% reduction in the total intensity of URN, with a notable drop of 1.22 dB. Nevertheless, this accomplishment is accompanied by a slight increase in fuel consumption of 3.25 MT, or 0.4%. Thus, in the case of a realistic shipping route, MOOF quantitatively demonstrates its efficacy in significantly reducing URN intensity levels without enforcing a major compromise on fuel consumption. Further discussion on the optimized speed profiles and prospects is presented.