bluuebunny/crossref_metadata_2025_split huggingface dataset:
Real-Time Recognition of Drill Bit Wear State Using Clustering Algorithm and GRU Neural Network
Authors: Zhang Qilong , Zheng Zeyu , Huang Zhongwei , Song Xianzhi , Wu Liwei , Zhang Ziyue 
Published: August 2024

Abstract
Drill bits are a critical factor influencing drilling efficiency. Due to the complexity of downhole conditions, it is challenging to achieve real-time and quantitative assessment of drill bit wear during the drilling process. Traditional approaches often rely on rate of penetration to assess downhole drill bit wear, which has inherent limitations and insufficient accuracy. To address the issues, this study presents a novel method for real-time identification of drill bit wear based on rock-breaking efficiency and mechanical specific energy, utilizing clustering algorithms and GRU neural networks. Initially, the working conditions of the drill bit, including bit sticking, vibration, bit bouncing, and bit balling, are annotated. Subsequently, an unsupervised clustering approach is employed to segment the drill bit wear process based on logging data, and the GRU neural network is used to establish a mapping relationship between surface drilling parameters and drill bit wear. This model was applied in Tianjin, China, where it monitored 18 drill bit trips. Among these, there were 3 instances with deviations, leading to an overall accuracy rate of 91.3%.
Investigation of Multiphase Flow Leak Detection in Pipeline Using Time Series Analysis Technique
Authors: Barooah Abinash , Khan Muhammad Saad , Ferroudji Hicham , Rahman Mohammad Azizur , Hassan Rashid , Hassan Ibrahim , Sleiti Ahmad K. , Gomari Sina Rezaei , Hamilton Matthew 
Published: August 2024

Abstract
Detecting chronic small leak sizes can be challenging because they may not produce significant or easily noticeable changes in flow rates or pressure differentials. Therefore, specialized techniques are often required to identify and locate chronic small leaks accurately in pipeline systems. The current study aims to address this gap by developing a method to identify multiphase flow leaks in pipelines using time series analysis techniques.
An experimental flow loop apparatus, featuring a 2-inch (0.0508 m) diameter and extending 22.6 feet (6.9 m) in length, has been employed to carry out our experiments. The experiments encompass a range of liquid flow rates varying between 170 and 350 kg/min and gas flow rates ranging from 10 to 60 g/min. The system was equipped with three distinct leak opening diameters, measuring 1.8 mm, 2.5 mm, and 3 mm, each separated by 90 mm. Data collected from four dynamic pressure sensors was subjected to time series analysis such as wavelet transforms to detect and pinpoint the location of pipeline leaks.
The obtained results indicate that dynamic pressure sensors are effective in detecting leak scenarios, as well as distinguishing between single and multiple leaks. However, for chronic small leaks, analyzing the standalone pressure response over time is generally not sufficient for detection. Time series analysis techniques play a crucial role in accurately identifying chronic small sized pipeline leaks. Discrete Wavelet Transform (DWT) was able to identify the point of leak opening and closing. Furthermore, DWT was able to reduce the false alarms for leak and no leak situations.
This study introduces the application of time series analysis on dynamic pressure to detect chronic small sized leaks in multiphase flow pipelines. Additionally, it explores the capacity of wavelet analysis to minimize the occurrence of false alarms for leak and non-leak scenarios thereby addressing crucial safety, environmental, and economic concerns.
Predicting Wave Propagation for Varying Bathymetry Using Conditional Convolutional Autoencoder Network
Authors: Deo Indu Kant , Vankateshwaran Akash , Jaiman Rajeev 
Published: August 2024

Abstract
In marine engineering applications, a crucial demand exists for the accurate and dependable prediction of far-field noise emanating from marine vessels. Traditional full-order models relying on the Navier-Stokes equations prove impractical, and advanced model reduction techniques can be inefficient for reliable far-field noise prediction. Recent advancements in deep learning-based reduced-order models have demonstrated effectiveness, achieving speeds several orders of magnitude faster than full-order simulations through the utilization of convolutional neural network architectures. Despite their effectiveness, existing models encounter considerable difficulties when forecasting wave propagation over extended time horizons and making predictions for distant locations. This research endeavors to enhance the predictive capacity of underwater radiated noise in far-field scenarios by refining the network architecture and integrating bathymetry information into the neural network input. Reduced-order models utilizing deep learning often rely on auto-regressive prediction, lacking information about far-field bathymetry. To overcome this limitation, we introduce a new range-conditional convolutional autoencoder network, which incorporates ocean bathymetry data into the input. To showcase the efficacy of our range-conditional convolutional autoencoder network, we examine a benchmark scenario involving far-field prediction over Dickin’s seamount. Our proposed architecture adeptly captures the transmission loss over a range-dependent, varying bathymetric profile. The architecture can be integrated into an adaptive management system for underwater radiated noise while providing real-time end-to-end mapping between near-field ship noise sources and marine mammals.
Robust CFD Analysis of Floating Wind Turbine Wave Responses With the FloatStepper Algorithm
Authors: Aliyar Sithik , Pierella Fabio , Roenby Johan , Tomaselli Pietro Danilo , Bredmose Henrik 
Published: August 2024

Abstract
In ocean environments, floating wind turbines are subject to both breaking waves and directional waves. While the response is often modelled through radiation-diffraction theory, the effects of higher-order wave loads are hereby limited to second order, and the damping often needs calibration against model tests. Better accuracy and full coverage of nonlinearity can be achieved through CFD. However, there is a limited robust Open Source CFD based six degrees of freedom (6-DOF) rigid body solvers, that can both generate different types of waves and also accurately simulate floating foundation motions. FloatStepper, a recent OpenFOAM-based rigid body motion algorithm, effectively addresses these differences, making it a good alternative to conventional body motion solvers. Its reliability and accuracy have been demonstrated in several benchmark cases, including single-phase and two-phase flows. The present study conducts a comprehensive examination the motion responses and mooring line tensions to unidirectional and multi-directional waves for a design variant of Stiesdal Offshore’s TetraSub floating foundation, using the FloatStepper algorithm. In particular, three categories of waves are investigated: 1) regular waves 2) unidirectional irregular and 3) multi-directional (3D) focusing waves. The numerical results are validated through comparison with experimental data from the 2023 test campaign of the Danish FloatLab project. The study contributes to the efficient use and validation of this robust CFD solver. It further extends the understanding of the multi-directional waves and wave-structure interaction for floating wind turbines, identifying potential limitations and areas for refinement in the modelling of this complex dynamics in CFD.
Vortex-Induced Motions of Floating Offshore Wind Turbines With Four Circular Columns: A Reduced Order Model Assessment of Small-Scale Experiments in a Towing Tank
Authors: Oliveira Éverton L. , Pesce Celso P. , Amaral Giovanni A. , Suzuki Hideyuki , Gonçalves Rodolfo T. 
Published: August 2024

Abstract
The complex movements caused by ocean currents affecting floating offshore platforms, specifically Vortex-Induced Motion (VIM), are the focus of this study. It examines VIM patterns observed in towing tank experiments involving a scaled model of a Floating Offshore Wind Turbine (FOWT) with a 4-circular-column platform and pontoons. A simplified mathematical model (ROM) was applied to analyze VIM, considering horizontal plane motions such as in-line, transverse, and yaw. The ROM model represented current forces using “wake variables”, adapting existing models initially developed for VIM of single-column platforms. It comprised eleven generalized coordinates, covering three for rigid body motion on the horizontal plane and a pair of wake variables for each column, resulting in an eleven-nonlinear second-order system of Ordinary Differential Equations (ODEs). The wake variable pairs followed van der Pol equations, incorporating hydrodynamic coefficients and parameters derived from prior experiments with low-draft cylinders. To simplify the numerical model, the hydrodynamic interactions among columns were not considered. Its accuracy was evaluated through a case study involving a small-scale experimental campaign. Simulations were performed at two different current incidence angles (0 and 45 degrees) across various reduced velocities. The simulations replicated the observed oscillations in the experimental trials, demonstrating fair agreement in transverse and yaw oscillations, including lock-in phenomena.
Wave-Structure-Seabed Interaction and Pore Pressure Measurements for Monopile Foundations: A 3D Experimental Study
Authors: Gkougkoudi-Papaioannou Maria , Pepi Yuri , Streicher Maximilian , Stuyts Bruno , Troch Peter 
Published: August 2024

Abstract
In the present study, 3D physical model tests have been performed at the Coastal & Ocean Basin (COB), in Ostend (Belgium) to investigate the wave-induced pore pressure development around a monopile foundation. The coupled hydrodynamic-geotechnical tests provide insight into the soil behaviour around the monopile foundation based on pore pressure measurements. Regular and irregular waves were generated to better simulate the engineering problem. Three different wave heights, wave periods and water depths were investigated. Differential pore pressure sensors were installed below the seabed surface in close proximity to the monopile to allow for the monitoring of the pore pressure in the soil directly adjacent to the structure, where the interaction between the monopile and the surrounding soil is most significant. The pore pressure sensors were positioned at varying depths below the seabed level to provide a broader perspective on how the soil’s response evolves with increasing depth from the seabed surface. First results show that increasing the wave height causes larger pore pressures at the seabed surface and, as a result, along the seabed foundation. On the other hand, the larger the water depth, the smaller the pore pressure development around the monopile foundation. These observations from the tests are in line with general expectations. This paper describes the experimental setup and presents the preliminary pore pressure results.
Vibration Analysis of Ship Shaft System Under Time-Varying Uncertainties Based on Interval Process Model
Authors: Shang Baoyou , Li Tianyun , Zhu Xiang , Wang Jianing 
Published: August 2024

Abstract
During navigation, the power system components (such as propeller, transmission shaft, etc.) on the ship will generate complex vibrations due to the action of various forms of excitation force. Due to the influence of the operating condition and the change of the wake field, the excitation force cannot be accurately measured and calculated, so the excitation force has the characteristics of uncertainty. In this paper, the non-random vibration response analysis method based on the convex model of non-probabilities is presented, which is used to solve the dynamic response limit of multi-degree of freedom system under time-varying uncertain excitation, and the expression for solving the dynamic response limit is given. The Monte Carlo simulation method is used to verify the reliability of the response boundary, which is the case with fewer excitation samples Improve the robustness of the dynamic response prediction of the shafting system to provide a useful reference.
ROP Calculation Methods Comparisons
Authors: Ma Shuai , Sui Dan 
Published: August 2024

Abstract
Efficiency in drilling operations is closely linked to the accurate estimation and control of the Rate of Penetration (ROP). This study presents a thorough comparative analysis of diverse ROP calculation methods, including Low Pass Filter, Kalman Filter, Sliding Mode Filter, and several others, all of which are utilized to extract ROP values from raw sensor measurements. The objective is to comprehensively evaluate the performance, advantages, and limitations of each method, specifically focusing on their ability to efficiently process and interpret drilling data in real-time. The work evaluates the accuracy of ROP calculations, the robustness of each method in handling noise, uncertainties and disturbances, and the computational efficiency required for their implementation. Case studies and comparative analyses provide valuable insights into the suitability of each technique.
The findings of this study hold significant implications for the drilling industry, offering valuable insights into the selection and deployment of ROP calculation methods. Engineers and developers can leverage this research to make informed decisions regarding the selection of the most appropriate ROP calculation method for their particular drilling operations. Moreover, this paper highlights the pivotal role of accurate measured ROP data in evaluating ROP models, impacting their accuracy, precision, and reliability. This paper offers a comprehensive and systematic evaluation of ROP calculation methods, providing a roadmap for the industry to process sensor measurements accurately and ultimately contribute to advancements in the field of offshore and marine engineering.
Experimental Investigation of Real-Scale Floating Solar Panel Assembly in Wind Tunnel
Authors: Arora Prince , Prasad Patel Badri , Ahmad Suhail , Kumar Jain Arvind , Joe Joe C. S. 
Published: August 2024

Abstract
Floating solar technology is gaining significant interest among researchers and on a commercial scale. FSPV (Floating Solar Photovoltaic) plants are being installed on water bodies such as thermal power plant reservoirs, balancing reservoirs, lakes, upstream of dams, backwaters, etc, from a small scale to utility scales. While this technology is gaining momentum due to its inherent advantages over the ground mount/rooftop solar system, its design requires further improvements and development to attain maturity. Wind-induced drag loads dominate the FSPV design, which is installed in relatively small reservoirs. On the other hand, wind-induced drag, wave, and current loading becomes critical when it is installed in the dam’s upstream reservoir where the open water area is in the range of 10 square Km.
The present study investigates the experimental wind tunnel test results of the real-scale dummy solar panel assembly used for FSPV parks. The testing was carried out at the National Wind Tunnel Facility (NWTF), IIT Kanpur. The test assembly includes five dummy solar panels of 2456 mm × 1134 mm, mounted on HDPE floaters in a 4+1 configuration. One dummy panel was instrumented for wind load measurement. The instrumented dummy panel was relocated from one position to another to get the wind load for each configuration. The tests were carried out for worst-case wind incidence angle, i.e. wind hitting the solar panel from the bottom at wind speed ranging from 0 Km/hr to 200 Km/hr. Drag and lift loads were obtained using load cells mounted underneath the panels. These results are useful for validating the numerical model.
The safety of the FSPV lies more in designing the anchoring and mooring system, which relies on wind load calculation. Realistic numerical models are required for the correct estimation of the wind load on the utility-scale FSPV, which can only be ensured after validating the numerical model with the experimental results on real-scale assembly. These well-established computational models can further be used for various changes in the study for which repeated experiments are not viable.
A Comparative Assessment of the Dynamic Responses of Solid Plate, Stiffened Plate, and Sandwich Plate of Equal Masses Under Explosive Loadings
Authors: Patel Murlidhar , Patel Shivdayal , Ahmad Suhail , Guedes Soares Carlos 
Published: August 2024

Abstract
For making a protective structure, the AL6XN steel has high ductility and excellent strength, and in the current study, it is used for making protective structures. The present work deals with a cost-effective numerical analysis of the protective structures’ blast performance. To investigate the significant effects on the air blast mitigation of a solid plate, a stiffened plate, and a sandwich plate of equal masses, their quarter parts are modeled. The use of quarter models significantly reduces the computation cost in terms of storage and computation time. The finite element models of a solid plate, a stiffened plate, and a sandwich plate are subjected to blast loads of 1–3 kg of TNT for a 0.1 m stand-off distance. To analyze the dynamic response of the modeled structures under blast loads, the Conventional Weapons Effects Program (CONWEP) module of Abaqus/Explicit is used. In air blast loadings, the structures are subjected to high impulse and deform with a high strain rate. To predict their plastic deformation behavior, the Johnson-Cook (J-C) plasticity model is used. This model is the most preferable for isotropic structures that are subject to large deformation with a high strain rate and high temperature. To verify the applicability of the numerical approach followed, the obtained results for solid plates’ deflection and impacted peak overpressures at applied blast conditions are compared with experimental data obtained from the literature. The blast performance comparison of the modeled structures deals with their deflection behavior, kinetic energy, energy absorption, and plastic deformations. The obtained results show that the sandwich plate has the greatest blast mitigation capacity, followed by the equivalent stiffened plate and the equivalent solid plate. Due to the sandwich plate’s smallest back face deflection and the highest capability to absorb energy, it is also applicable to the bulkhead, hull, and decks of ships.
Case Studies of Elastic Closed Fish Cage Concepts in Waves
Authors: Firoozkoohi Reza , Ravinthrakumar Senthuran 
Published: August 2024

Abstract
This paper demonstrate usage of a coupled linear hydrodynamic and structural model to assess the elastic response of closed fish cages in waves. From a design point of view it is important to avoid coupling between internal sloshing and the structure. This problem is addressed by assessing the elastic response of two closed fish cages made of an uniform elastic material. A vertical cylinder cage (bucket concept) and an ellipsoidal cage (egg concept inspired by Ovum AS design) with similar internal volume are investigated. WAMIT which is a software based on Boundary Element Method is used to compute hydrodynamic forces on rigid and elastic modes of motion. LSDYNA which is a Finite Element Method software is used to compute dry elastic mode shapes to be used as basis functions in the modal analysis. The computations were performed in frequency domain. The effective stress, i.e, Von Mises stress, is computed for the maximum responses in frequency domain to be compared with yield stress of the manufacturing material. The focus is on elastic cages for which the manufacturing material withstands bending. The effect of variation of stiffness on elastic response and its interaction with sloshing is addressed. The numerical method is explained briefly and its advantages and shortcomings are addressed. It is shown that the egg concept has a much smaller hydroelastic response than the bucket concept for the same material properties.
Typhoon Wave Prediction Using Long Short-Term Memory Networks for Offshore Windfarm on Western Coast of Taiwan
Authors: Chao Wei-Ting , Young Chih-Chieh , Hsu Tai-Wen 
Published: August 2024

Abstract
An accurate and efficient typhoon wave prediction model is important for improving the efficiency of offshore wind farm management. In the earlier studies, short-lead-time (i.e., 1 to 3 hours) typhoon wave prediction models were developed for the Taiwan coastal area. These models were constructed by BPNN with local meteorological information. However, Sufficient prediction lead-time is essential for early warning and response to offshore wind farms during typhoon events. Furthermore, past research on typhoon waves along the western coast of Taiwan often presented an underestimated tendency due to the structure of the typhoon being destroyed by the Central Mountain Range. This study aims to establish a novel long-lead-time typhoon wave prediction model using Long Shor-Term Memory (LSTM) networks while carefully considering typhoon parameters. The basic concept of LSTM is to utilize the memory cell to capture the features or vectors of time-related data, significantly enhancing prediction accuracy. The results of LSTM demonstrate high consistency with in-situ data for 1-hour lead time (i.e., the correlation coefficient is up to 0.98). For longer lead time (e.g., 6 hours), the method significantly improves learning and generalizing capability more than shallow learning methods. The correlation coefficients for training and validation reach 0.91 and 0.86, respectively.
Integrated Operation of Underwater Pipeline Inspection and Repair in Dry Cabin
Authors: Chen Jiawang , Li Miao , Guo Jin , Chen Junrong , Zhou Peng , Gao Qiaoling , Nan Liwen 
Published: August 2024

Abstract
Submarine pipelines are subject to complex working loads, environmental loads, and accident risks for a long time and have excellent failure probability. The underwater dry maintenance method can apply the land maintenance technology to the seabed and achieve the maintenance quality on the land. Therefore, we designed a dry cabin for underwater operations that can achieve pipeline inspection and repair. For pipeline inspection, a 3D laser scanning mechanism was designed to map the external features of the pipeline, and an ultrasonic non-destructive detection mechanism was designed to detect metal internal defects such as pipeline corrosion and cracks. For pipeline repair, a composite material winding mechanism was designed to wrap and reinforce the pipeline. Moreover, establishing a stable seal between the dry cabin and the pipeline is a prerequisite for safe underwater dry operations. Therefore, a new type D seal strip composed of rubber and EPDM foam was designed. The comprehensive optimal structure of seal strip was obtained based on the Response Surface Methodology. In the near future, we will carry out sea trial application to verify the functions of the device.