bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of the Euphrates River’s Water Quality in Front of and Behind the Haditha Dam in Anbar Province, Iraq
Authors: Jalal Arkan D , Ani Yasir Al , Thameel Salah S , Ismael Zainab M 
Published: August 2023

Abstract
Contaminants in natural water continue to be one of the largest environmental issues on the planet. This is due to the fact that due to population expansion, urbanization, agricultural practices, and industrialization, there is a significant increase in the demand for freshwater and a water crisis in arid and semi-arid areas. The present study aimed to assess the suitability of water quality at Haditha Dam. In this study, 9 parameters, including Nitrate NO3, Carbonate CO3, bicarbonate HCO3, Sulphate SO4, Chloride Cl, Calcium Ca, Magnesium Mg, Sodium Na, and Potassium K were measured and investigated to assess water quality for Haditha Dam Project in both sides (Behind and in front of the dam). The current study focuses on the examination of water quality data collected over a one-year period from both sides of the Euphrates River through the collection of 48 samples. The parameters that were examined used the accepted techniques. Findings showed that average concentrations were lowest during the dry season and highest during the rainy season for K, Ca, Na, Mg, Cl, and SO4. However, HCO3 and CO3 concentrations were the highest averages in the dry season, while the lowest average was in the wet season. The results were compared with Iraqi standards for water quality and the World Health Organization (WHO). The planning and logical management of water resources, including the possibility of using them for irrigation and drinking water, can benefit from this study. According to the findings, river water is deemed unsafe for drinking and human consumption, however it can be utilized for irrigation.
Response of Anatomical Characteristics of Nile Flower Eichhornia crassipes to Environmental Changes and their Impact on Tigris Water Quality
Authors: Alsahan Irfan W , Mohammad Hala A , Al-Blesh Adnan H 
Published: August 2023

Abstract
The current study was conducted on the Tigris River in the distance between Qayyarah district of Nineveh province and Baiji district of Salahuddin province by five stations (Al-Gayyarah, Jisr Al-Shirgat, Asdeira, Al-Zuwia and Almsahag). Anatomical Characteristics of Nile flower Eichhornia crassipes were studied. Some qualitative properties of river water were studied. The results indicated that there were significant differences between the study stations in all anatomical characteristics of the plant, Significant differences were found in the different study stations in all the characteristics of the upper and lower skin of the leaves of the Nile flower plants, it is the dimensions of stomata and its index and the average dimensions of the cells of the upper and lower skin. For the stems of the Nile flower plants, anatomical characteristics showed significant differences with different study stations. Al- Mosahak station achieved the highest stomatal dimensions of 15 and 13 μm for length and width respectively. Al-Gayyarah station excelled in the highest averages of the stomata index and average length × width of normal cells with values of 14 and 32 × 15 μm respectively. The highest mean of the physical characteristics of the river water was 1407 mg / L of total dissolved solids at the Al-Zuwia station in December, 8.4 for pH at Al-Gayyarah and Jisr Al-Shirgat stations during January, and 1.4 mg / L for BOD5 in Al-Gayyarah station during March, 2.3 mg / L for total hardness at Asdira station in February, 1.02 mg / L of nitrate at Almsahag station in December, 1.231 mg / L for sulfate at Al-Gayyarah station in January, 2.38 mg / L for sodium at Al-Zauwia station in December, and 1.2 mg / L for potassium at Almsahag station in March.
Influence of interface-sharpening on the ship’s wave system
Authors: Perić Robinson , Berndt Jannes , Abdel-Maksoud Moustafa 
Published: August 2023

Abstract
This article investigates the influence of the interface-sharpening algorithm on the wave height near ships in flow simulations. The focus is on finite-volume-based flow simulations with the volume of fluid (VOF) method to account for the two phases, gaseous air and liquid water. A common approach to obtain a comparatively sharp interface between the water phase and the air phase is to use interface-capturing approaches combined with interface-sharpening schemes. The present work demonstrates that the interface-sharpening schemes can contain case-dependent parameters, and that the optimum values for these parameters may not be known a priori. Therefore, if the parameters are not set correctly, the wave height at some distance to the ship may be unrealistically small or large. To demonstrate this, flow simulations of calm-water resistance of the KCS ship are performed with different discretizations and different parameters of the interface-sharpening scheme. The present simulation results are compared to experimental results to provide recommendations on the optimum choice of interface-sharpening parameters and guidelines for performing such flow simulations, to improve predictions of the ship’s wave system.
Hydrodynamic response of dual obliquely submerged non-uniform flexible thin plates
Authors: Singh Mansi , Gayen R 
Published: August 2023

Abstract
Examining inclined flexible plates with variable thickness becomes crucial when it comes to optimizing or achieving controlled reflection and transmission of waves, especially for the construction of breakwaters. Unlike horizontal breakwaters, inclined barriers have the ability to penetrate through numerous layers of the fluid, having different particle velocities and foster their interactions. This causes wave breaking which leads to loss of wave energy. Also, despite exhibiting a similar behavior, vertical structures do not attenuate waves as effectively as inclined ones do. Additionally, the resonant motion of the fluid trapped between two structures proves to enhance the attenuation, thus it is recommended to include dual structures in the model rather than just one. Therefore in the present study, we examine the water wave scattering phenomenon by a pair of symmetric flexible thin plates with non-uniform thickness obliquely submerged in deep water. We use the linear water wave theory and Kirchhoff’s thin plate theory to model the physical problem. The boundary value problem is converted into a system of coupled integral equations using repeated integration and Green’s integral theorem. Using appropriate approximations, this system is solved and its solutions are used to determine numerical values of different hydrodynamic quantities. Results of two horizontal as well as two vertical plates could be obtained from the present model, thus it is a very general model. Also results are illustrated to analyze the contribution of the thickness variation and the inclinations of the two flexible plates towards the wave scattering process and some related physical quantities.
A Numerical Sensitivity Analysis of Fluid-Structure Interaction Simulations on Slamming Loads and Responses
Authors: Hosseinzadeh Saeed , Topa Ameen , Tabri Kristjan 
Published: August 2023

Abstract
This paper presents a parametric study on the Multi Material Arbitrary Lagrangian–Eulerian (MMALE) method for hydroelastic analysis of a non-prismatic stiffened aluminium wedge. An explicit finite element formulation with a penalty-based coupling technique is employed to evaluate the impact-induced loads and responses during free-fall water entry. Based on the penalty factor, damping factor, and number of coupling points, a sensitivity analysis is carried out. It is shown that the penalty coupling method can generate high-frequency oscillations due to the nature of the phenomenon that may affect the predicted results of slamming loads. The computed results on the stiffened and unstiffened plates of the wedge are compared with published experimental data in terms of vertical acceleration, pressure distributions, and strain responses at different locations. A reasonable agreement can be found between the numerical results and the measured values. It is found that a combination of penalty and damping can improve the simulation results and reduce numerical instabilities in hydroelastic slamming simulations.
Numerical investigations of dam-break flow impacting on an elastic beam using various FSI coupling algorithms
Authors: Zhang Wenjie , Yang Xiaolong , Wang Jianhua 
Published: August 2023

Abstract
The occurrence of green water and slamming in severe sea conditions can often be simplified as a dam-break problem. The flow characteristics of dam-break are similar with those on a ship’s deck and can result in structural damage. In this study, the fluid-structure interaction (FSI) of dam-break flow impacting on an elastic beam is investigated based on CFD-FEM method. The FSI coupling is solved in a partitioned manner. The fluid field is solved by OpenFOAM and the structure is calculated by self-developed code using FEM. The two-way coupling algorithm has been implemented to update the mesh of the fluid field. An investigation on mesh independence and the comparison of results with other methods have been conducted to validate the simulation results. After that, three types of FSI coupling algorithms have been utilized to examine the impact on both computational accuracy and efficiency. It is studied that the computational accuracy of all three FSI coupling algorithms is in good agreement. The FSI coupling algorithm utilizing weak iteration exhibits excellent performance in terms of both computational accuracy and efficiency. For the strong coupling algorithm, it is crucial to make a rational selection of the outer and inner iteration numbers in PIMPLE loops.
Numerical Simulation of Ship-Pack Ice-Water Interaction and Motion of Pack Ice Based on CFD-DEM Method
Authors: Zou Ming , Tang Xiang-Jie , Zou Lu , Zou Zao-Jian 
Published: August 2023

Abstract
When a ship sails in pack ice area, it not only collides with the ice but also interacts with the water, generating ship-generated waves. The role and influence of ship-generated waves on the ship-ice-water interaction have not been thoroughly studied. In this study, a numerical model with ship-generated waves is established using a coupled Computational Fluid Dynamics (CFD) and Discrete Element Method (DEM), and an appropriate contact model is selected for numerical simulations. Meanwhile, a simplified numerical model without ship-generated waves is proposed. By comparing the simulation results under the same simulation conditions with and without ship-generated waves, the effects of ship-generated waves on the phenomena of ship-ice-water interaction, longitudinal and lateral contact forces between the ship and pack ice, and ice resistance are analysed, along with the underlying mechanisms. The results indicate that the ship-generated waves can mitigate and reduce the collision intensity and contact frequency between the ship and pack ice, resulting in a decrease in the contact forces and ultimately achieving a significant reduction in ice resistance. Furthermore, this mitigation effect becomes more pronounced with increasing ship speed.
A CFD investigation of the effects of passing ship on a small size ice floe
Authors: Jiang Z , Suominen M , Tavakoli S , Kujala P , Hirdaris S 
Published: August 2023

Abstract
A RANS (Reynolds Averaged Navier-Stokes) CFD STAR-CCM+ model is used to investigate the hydrodynamic interactions between a ship and a circular ice floe. The overset mesh technique is employed to simulate the advancing movement of the passing ship. The ship has a hull of similar configuration to the KCS MOERI container ship. The ice floe has a diameter of 30% of the ship’s length and a thickness of 3 m. The paper primarily focuses on the motions of the ice floe and the hydrodynamic forces induced by the ship progressing in different speeds and calm water conditions. A parametric study on the influence of the ice floe surge and sway motions and associated hydrodynamic loads is presented. It is concluded that ship-generated waves can significantly affect the motions of the ice floe and the influence on sway is greater than that on surge. The ship speed is also found to have a distinct impact on ice floe motions.
An example of numerical ice tank based on DEM simulation and physical model testing
Authors: Tian Yukui , Yang Dongbao , Gang Xuhao , Yu Chaoge , Ji Shungying 
Published: August 2023

Abstract
The determination of ice loads on polar ships and offshore structures is of great significance for ice-resistant design, safe operation, and structural integrity management in ice-infested waters. The physical model testing carried out in ice tank/basin is usually an important technical approach to evaluate the ice loads, however, the high cost and time consumption make it difficult to perform multiple repetitions or large number of trials for this purpose. Recently, the rapid development of high-performance computation techniques provides a usable alternative where the numerical methods represented by the discrete element method (DEM) have made remarkable contributions to the ice load predictions. On basis of DEM simulation validated by physical model testing, numerical ice tank can be developed as an effective supplement to its counterpart. In this paper, such an example of numerical ice tank adopting GPU computational mechanism and DEM modelling algorithm was established with respect to the small ice model basin of China Ship Scientific Research Center (CSSRC-SIMB). The numerical ice tank was calibrated and further optimized with physical model tests on typical structures of vertical cylinder and inclined flat plate in level ice sheets by making agreements of both globe value and time history of the ice loads. Then it was practiced for modelling the tests of Wass bow advancing in level ice performed in SIMB separately. It is demonstrated by the comparisons of ice failure details and ice loads that the numerical ice tank can precisely simulate the ice-structure interactions and determine the ice loads under the same initial conditions of physical model testing. In the end, the advantages as well as the challenges of the numerical ice tank are discussed.
Impact of direct seakeeping computation on ship Underwater Keel Clearance prediction
Authors: Gallucci Filippo , Vernengo Giuliano 
Published: August 2023

AbstractThe continuous increase in worldwide ship traffic poses relevant challenges on the management of the onboard safety during navigation and specific operations. Among these issues, navigation in relatively shallow water areas, being either channels or port areas, is of major interest especially when rough weather conditions occur due to the increased risk of grounding. Such a problem, which is deeply related to the seakeeping performance of a ship, can be tackled by different perspectives. In the present paper, the approach proposed by the PIANC recommendations, typically used to design port and channels areas and infrastructures, are analysed from the perspective of ship design hence dealing with its operability. In particular, the dynamic Underwater Keel Clearance (UKC) of a ship is studied based on direct seakeeping computations to assess the effect of the operability conditions in terms of sea states and ship speed at different wave encounter angles.
Dynamic response of offshore triceratops under regular waves with tether postulated failure
Authors: Chandrasekaran Srinivasan , Rao Ganta Shanmukha 
Published: August 2023

Abstract
Triceratops are innovative offshore platforms that consist of a deck, three buoyant legs, and ball joints. Their deck is supported by buoyant legs, which, in turn, are restrained on the sea bed using taut-moored tubular tethers. Ball joints partially isolate the deck from the buoyant legs by restraining the transfer of rotations from the legs to the deck. Triceratops platforms exhibit a monolithic structural action in the vertical plane and a hybrid dynamic behavior resembling tension leg platforms and spar buoys. The present study investigates their dynamic response in regular waves. Response amplitude operators (RAOs) are estimated for intact and postulated failure conditions of the tethers. Based on detailed numerical investigations, it is seen that the pitch response of the deck increases significantly under the postulated failure of tethers, which are otherwise absent due to the presence of ball joints. Marginal change in surge response, even under tether failure, confirms the suitability of triceratops for ultra-deepwater installations. The fatigue life of tethers before and after postulated failure conditions is compared using the S-N curve approach and noticed that the adjacent tethers’ fatigue life reduces significantly under postulated failure conditions of tethers.
Numerical simulations of the flows past two parallel square columns by MPS method
Authors: Huang Congyi , Yang Xiaolong , Wan Decheng 
Published: August 2023

Abstract
The hydrodynamic interactions between an offshore platform and surrounding water mainly occurs in way of the pile legs, and the flow past the pile legs can be simplified to the flow past the columns. This is the reason why it is of great significance to simulate the flow around multiple columns with accuracy. In this paper, based on a mesh-less method, Moving Particle Semi-implicit (MPS) method, the MLParticle-SJTU solver is used to simulate the flow past two parallel square columns. Firstly, the reliability and accuracy of the solver is verified by simulating the Poiseuille flow, in which the no-slip boundary condition is applied. Then, the flow past two parallel square columns with different spacing between the two columns is simulated when the Reynold number is 40. The influence of spacing on flow pattern, force on columns and the vortex shedding frequency is analyzed. It is found that when the spacing is relatively small, small vortices will be attached to the surface of the columns. As the spacing ratio increases, periodic shedding of vortices will occur.
Shallow waters resistance of an accelerating ship
Authors: Liu Y H , Terziev M 
Published: August 2023

Abstract
This paper investigates the acceleration resistance of a vessel in shallow waters using potential flow and CFD methods. Results indicated a pronounced resistance peak near the critical depth Froude number. The peak’s location and magnitude were sensitive to acceleration intensity and water depth. Excellent agreement between potential flow and CFD methods was found in low and high depth Froude number ranges, suggesting their effectiveness and cost-efficiency. However, non-linear effects affected the resistance peak’s magnitude and position, leading to slight disagreements between the methods. The solvers’ variation was observed to be sensitive to the investigated parameters.
Study of Influencing Factors on CFD Method and Separated Flow by the Virtual Static Captive Test
Authors: Yang C , Zeng K , Chu J L , Han Y , Gu M 
Published: August 2023

Abstract
In this paper, Computational Fluid Dynamic (CFD) methods are adopted to predict the manoeuvring behaviour of the KCS benchmark model. At first instance, the model is calibrated on the basis of three factors namely (a) turbulence model, (b) grid size and (c) time step. Secondly, a Static Oblique Towing Test (OTT) that utilises the SST K-ω turbulence model with a grid number of 1.64 million and a time step of 0.01 s is conducted. The maximum difference of the lateral force between the port and starboard ship sides is observed at x/Lpp
= 0.055. Finally, application of Reynold Averaged Navier Stokes (RANS) and Dettached Eddy Simulation (DES) CFD models indicates that the latter may be preferable in terms of capturing the oblique flow field.
Multi-scale characteristics investigation of sheet/cloud cavitation
Authors: Tian B C , Li L M , Wu Q , Huang B , Wang G Y 
Published: August 2023

Abstract
Sheet and cloud cavitation involve the formation of large-scale cavities and microbubbles across a wide range of length scales. In this study, a two-way coupling Eulerian-Lagrangian algorithm was utilized to simulate the cavitating flow around a NACA66 hydrofoil at an incidence of 8 degrees and a cavitation number of 1.2. The large eddy simulation (LES) and volume of fraction (VOF) methods are used to capture the large scale vapor structures in Eulerian frame. Meanwhile, the discrete bubble model (DBM) and simplified Rayleigh-Plesset equation are implied to solve the dynamic of Lagrangian microbubbles smaller than local grid scale. The results indicate that large-scale cavities are periodically shed downstream, influenced alternatively by the re-entrant jet and shock wave mechanisms, resulting in periodic variations of both the number and Sauter mean diameter of microscale bubbles. During the quasi-periodic evolution process of sheet/cloud cavitation, the microbubbles scatter around the large scale cavities where have strong turbulence intensity and high vorticity, and the probability density function of discrete bubble diameter similarly conforms to Gamma distribution with the dominant bubble size between 30 and 70μm. During the growth of an attached cavity, the number density of bubbles follows a power-law scaling with a value of -5/3 on radius. For the other stages, the bubble size spectrum of smaller microbubbles exhibits a -2/3 power-law scaling when the diameter of the microbubble is less than 200 μm. For larger bubbles with a diameter greater than 300 μm, the bubble density is proportional to the bubble radius to the power of -6.
Rudder hydrodynamics behind a propeller rotating ahead and astern
Authors: Lu Suli , Boucetta Djahida , Hoydonck Wim Van , Lataire Evert , Delefortrie Guillaume 
Published: August 2023

Abstract
Ships sailing in harbour environments will experience four-quadrant manoeuvres, based on the direction of ship velocity and propeller rate. A better understanding of ship hydrodynamics in such manoeuvres will contribute to the navigation safety. Aimed at ships equipped with a conventional single propeller and single rudder, the hydrodynamic performance of a rudder with the engine ahead and astern is studied. The KP505 propeller and NACA 0018 semi-balanced rudder (from the KCS benchmark ship) are selected for numerical studies for extended experimental data published. After validating numerical methods with open-water test data for the single propeller and the single rudder, CFD simulations based on RANS methods are conducted for different advance ratios ahead and astern, with rudder deflections ranging from 0 to 15 degrees. To understand propeller impact on lift and drag forces of the rudder in different working conditions, inflow to the rudder in propeller slipstreams are analysed by extracting the flow field data in different profiles along the rudder span. Streamlines around the rudder and pressure distributions on the rudder surfaces, along with the turbulent kinematic energy distributions and the vortex structures visualised by Q-criterion, are compared to reveal propeller-rudder interaction mechanisms in ahead and astern conditions. The study shows that the propeller rotation mode has a significant impact on rudder inflow patterns, and induced rudder forces change in different trends with propeller loading variations.