检索结果-内蒙古大学图书馆

2025 IEEE Underwater Technology, UT 2025

作者： Cheng, Ming-Hung Hwang, Robert R. National Academy of Marine Research Marine Industry and Engineering Research Center Kaohsiung Taiwan National Taiwan Ocean University Department of System Engineering and Naval Architecture Keelung Taiwan

ISBN: (纸本)9798331534189

Taiwan, surrounded by the ocean, benefits from the powerful Kuroshio Current along its eastern coastline, presenting substantial potential for harnessing marine energy resources. To capitalize on these opportunities, the National Academy of Marine Research initiated research and development efforts in 2020, focusing on key technologies for ocean current energy and conducting sea trials. These efforts are expected to culminate in the development of a Floating Kuroshio Turbine (FKT). To gain a comprehensive understanding of the FKT's underwater operations, this study employs a series of numerical simulations. Using the Navier-Stokes equations, combined with the $\mathrm{k}-\varepsilon$ turbulence model and dynamic mesh techniques, a numerical model for fluid-structure interaction is developed. The simulation results reveal that as flow velocity increases, the vortices behind the unit become increasingly complex. For the 20 kW FKT, the dual-blade system with counter-rotating blades reduces the downstream impact distance compared to a single-unit setup, limiting it to approximately 4 to 5 times the length of the unit's longest side. The primary objective of this study is to enhance understanding of the system's performance under different FKT, providing critical insights for future design optimizations and environmental impact assessments. © 2025 IEEE.

关键词： Navier Stokes equations

来源：评论

学校读者我要写书评

暂无评论

Search method for ship regulations based on semantic similarity using natural language processing

引用

Ships and Offshore Structures 2025年

作者： Han, In-Su Roh, Myung-Il Kong, Min-Chul Park, Seoyoon Lee, Jeongyoul Department of Naval Architecture and Ocean Engineering Seoul National University Seoul Korea Republic of Department of Naval Architecture and Ocean Engineering and Research Institute of Marine Systems Engineering Seoul National University Seoul Korea Republic of DT System Development Team Korean Register Busan Korea Republic of

We proposed a ship regulation search method based on semantic similarities using natural language processing (NLP) technology. First, we proposed a data preprocessing algorithm to convert ship regulations in the PDF format into a dataset for search purposes. We extracted basic elements from ship regulations, removed elements that hindered search accuracy, and generated a search dataset reflecting hierarchical structural relationships. We compared various NLP models to evaluate the semantic similarity between the generated dataset and the search queries of the workers. Then, we proposed an effective search method for ship regulations. To validate the effectiveness of the proposed method, we applied it to the technical rules for classifying the Korean Register. The results verify that the proposed search method can provide ship regulations to workers with high semantic similarity as search queries in a short time. © 2025 Informa UK Limited, trading as Taylor & Francis Group.

关键词： Natural language processing systems

来源：评论

学校读者我要写书评

暂无评论

Numerical Study for the Variations of Flow Field During FKT Operation

Numerical Study for the Variations of Flow Field During FKT ...

引用

International Symposium on Underwater Technology

作者： Ming-Hung Cheng Robert R. Hwang Marine Industry and Engineering Research Center National Academy of Marine Research Kaohsiung Taiwan Department of System Engineering and Naval Architecture National Taiwan Ocean University Keelung Taiwan

ISBN: (数字)9798331534189

ISBN: (纸本)9798331534196

关键词： Oceans system performance Simulation Numerical simulation Mathematical models Numerical models Underwater technology Turbines Research and development Navier-Stokes equations

来源：评论

学校读者我要写书评

暂无评论

Comparative study of Reynolds-averaged Navier–Stokes and partially-averaged Navier–Stokes models for cavitation flows around a hemispherical head-form body

引用

European Journal of Mechanics, B/Fluids 2025年 113卷

作者： Park, Junyoung Seok, Woochan Department of Marine Convergence Engineering Pukyong National University Busan Korea Republic of Hyundai Maritime Research Institute HD Hyundai Heavy Industries Ulsan Korea Republic of Department of Naval Architecture and Marine System Engineering Pukyong National University Busan Korea Republic of

Cavitation causes the erosion of marine propellers and induces noise and vibration within the mechanical system. In this study, the results of Reynolds-averaged Navier–Stokes (RANS) and partially-averaged Navier–Stokes (PANS) models for detecting cavitation flows around a three-dimensional (3D) hemispherical head-form body were compared. These turbulence models can accurately depict the unsteady characteristics of cavitation flows. To investigate the effect of these turbulence models on flow characteristics, we analyzed the periodic shedding of the sheet and cloud cavitation. In addition to the shape of the cavity around the body, the pressure, velocity, turbulent kinetic energy, and turbulent viscosity were compared to identify the differences between the turbulent models. An open-source platform OpenFOAM was used for this analysis. The results revealed that the pressure coefficient in the PANS model was consistent with the experimental data. Furthermore, the PANS model provided an accurate depiction of the development process of sheet and cloud cavitation. © 2025

关键词： Cavitation Computational Fluid Dynamics (CFD) Hemispherical head-form body OpenFOAM (Open-source Field Operation and Manipulation) Partially-averaged Navier–Stokes (PANS) Reynolds-averaged Navier–Stokes (RANS)

来源：评论

学校读者我要写书评

暂无评论

Numerical Investigation of Cavitation Models Combined with RANS and PANS Turbulence Models for Cavitating Flow Around a Hemispherical Head-Form Body

引用

Journal of Marine Science and engineering 2025年第4期13卷 821-821页

作者： Lee, Hyeri Lee, Changhun Kim, Myoung-Soo Seok, Woochan Department of Marine Convergence Engineering Pukyong National University Busan48513 Korea Republic of Advanced-Intelligent Ship Research Division Korea Research Institute of Ships and Ocean Engineering Daejeon34103 Korea Republic of Department of Naval Architecture and Marine System Engineering Pukyong National University Busan48513 Korea Republic of

Accurate prediction of cavitating flows is essential for improving the performance and durability of marine and hydrodynamic systems. This study investigates the influence of different cavitation models—Kunz, Merkle, and Schnerr–Sauer—on the numerical prediction of cavitation around a hemispherical head-form body using computational fluid dynamics (CFD). Additionally, the effects of turbulence modeling approaches, including Reynolds-averaged Navier–Stokes (RANS) and partially averaged Navier–Stokes (PANS), are examined to assess their capability in capturing transient cavitation structures and turbulence interactions. The results indicate that the Schnerr–Sauer model, which incorporates bubble dynamics based on the Rayleigh–Plesset equation, provides the most accurate prediction of cavitation structures, closely aligning with experimental data. The Merkle model shows intermediate accuracy, while the Kunz model tends to overpredict cavity closure, limiting its ability to capture unsteady cavitation dynamics. Furthermore, the PANS turbulence model demonstrates superior performance over RANS by resolving more transient cavitation phenomena, such as cavity shedding and re-entrant jets, leading to improved accuracy in pressure distribution and vapor volume fraction predictions. The combination of the PANS turbulence model with the Schnerr–Sauer cavitation model yields the most consistent results with experimental observations, highlighting its effectiveness in modeling highly dynamic cavitating flows. © 2025 by the authors.

关键词： Cavitation

来源：评论

学校读者我要写书评

暂无评论

Dynamics and control of marine mechatronic oscillators using electromagnetic coupling and switching power electronics

e-Prime - Advances in Electrical Engineering, Electronics an...

引用

e-Prime - Advances in Electrical engineering, Electronics and Energy 2025年 11卷

作者： Tsakyridis, Georgios Xiros, Nikolaos I. Litsardakis, George Rovithakis, George German Aerospace Center – Institute of Space Systems Department of System Analysis Space Segment Bremen Germany Department of Naval Architecture and Marine Engineering University of New Orleans New Orleans LA United States Department of Electrical and Computer Engineering Aristotle University of Thessaloniki Thessaloniki Greece

Developing force control mechanisms employing electromagnetic solutions is on the rise in active control applications for flexible mechanical systems, like marine engines and shipboard machinery. Electromagnetic control devices offer superior performance indicators compared to traditional mechanical force actuators in terms of longevity, energy efficiency, maintenance requirements, rapid control response, and high operating speeds. This article investigates the use of magnetic actuation and switching power electronics in addressing the stabilization and tracking control challenges encountered in the dynamics of a mechanical system with a single degree of freedom, comprising mass, spring, and damper elements. Particularly, a linear mechanical oscillator is nonlinearly coupled with an electromagnet and its associated driving circuit via the magnetic field. The electromagnetically actuated mechanical system exhibits characteristics of a deferentially flat nonlinear system. A control strategy is suggested for the purpose of tracking reference position trajectories using output feedback linearization. The synthetic linearized control signal is subsequently guided to a DC–DC buck converter, able to regulate the system's input voltage in a wide range of operation, by switching the duty cycle. The converter is described using a precise electrical model of the system, accounting for parasitic resistances in the inductor, capacitor, and switches. An averaged state space approach is utilized to create a mathematical nonlinear model for the converter which is then linearized by employing the Exact Feedback Linearization technique. By applying optimal control theory, the controller's coefficients are fine-tuned for optimal performance. To assess the proposed method's performance, the dynamics of the compensated mechatronic system is simulated using MATLAB/Simulink. The simulation results demonstrate that the proposed control scheme choice for active control of vibrating mechanic

关键词： Electromagnet-mass–spring–damper (mechatronic oscillator) system Electromagnetic control Exact Feedback Linearization Linear Quadratic Regulator (LQR) controller Magnetic actuation Marine oscillators Switching power electronics

来源：评论

学校读者我要写书评

暂无评论

The effect of core configurations on the energy-absorbing behaviour of all-composite sandwich structures

引用

Structures 2025年 77卷

作者： Zhang, Wenxin Zhou, Jin Wang, Jizhen Qi, Jiangwei Zheng, Cheng Guan, Zhongwei Cantwell, Wesley J. State key laboratory for manufacturing system engineering School of Mechanical Engineering Xi'an Jiaotong University Xi'an710049 China Department of Naval Architecture Ocean and Structural Engineering School of Transportation Wuhan University of Technology China School of Mechanical Engineering Chengdu University Chengdu610106 China Department of Aerospace Engineering Khalifa University of Science and Technology United Arab Emirates

This paper presents the energy absorption characteristics of all-composite sandwich structures filled with PVC foam subjected to quasi-static and dynamic loading. Compression and drop-weight impact tests have been undertaken to evaluate the mechanical response of sandwich structures made with glass fibre/epoxy (GFRP) and carbon fibre/epoxy (CFRP) corrugation cores embedded with PVC foams. The corrugation core thicknesses are in a range from 0.25 to 1.25 mm, whilst the PVC foams are of a density of 40, 80 and 130 kg/m3, respectively. The energy-absorbing capability is evaluated by determining the specific energy absorption (SEA) of each configuration. The mechanical response of the sandwich structures is also modelled using the finite element method, which is validated against the corresponding experimental data. The relationship between the density of PVC foam and the thickness of corrugation composite is explored via a two-way analysis of variance. The results show that both thick corrugated core and high-density foam contribute to the increase of the compressive strength and specific energy absorption of the structure. However, the structure with the optimal performance is not the structure with the thickest corrugation core and the highest foam density. In contrast, C130 foam-filled CFRP corrugation core with a thickness of 0.75 mm is the most attractive option in terms of specific energy absorption and compression strength. © 2025 Institution of Structural Engineers

关键词： Sandwich structures

来源：评论

学校读者我要写书评

暂无评论

The effect of dynamic operating conditions on nano-particle emissions from a light-duty diesel engine applicable to prime and auxiliary machines on marine vessels

引用

INTERNATIONAL JOURNAL OF naval architecture AND OCEAN engineering 2012年第4期4卷 403-411页

作者： Lee, Hyungmin Jeong, Yeonhwan Department of Naval Propulsion System Engineering Republic of Korea Naval Academy Department of Naval Architecture and Ocean Engineering Republic of Korea Naval Academy

This study presents the nano-sized particle emission characteristics from a small turbocharged common fail diesel engine applicable to prime and auxiliary machines on marine vessels. The experiments were conducted under dynamic engine operating conditions, such as steady-state, cold start, and transient conditions. The particle number and size distributions were analyzed with a high resolution PM analyzer The diesel oxidation catalyst (DOC) had an insignificant effect on the reduction in particle number but particle number emissions were drastically reduced by 3 to 4 orders of magnitude downstream of the diesel particulate filter (DPF) at various steady conditions. Under high speed and load conditions, the particle filtering efficiency was decreased by the partial combustion of trapped particles inside the DPF because of the high exhaust temperature caused by the increased particle number concentration. Retarded fuel injection timing and higher EGR rates led to increased particle number emissions. As the temperature inside the DPF increased from 25 degrees C to 300 degrees C the peak particle number level was reduced by 70% compared to cold start conditions. High levels of nucleation mode particle generation were found in the deceleration phases during the transient tests.

关键词： Cold start DPF Prime and auxiliary machine Nano-sized PM Transient

来源：评论

学校读者我要写书评

暂无评论

Assessing the influence of offshore wind turbine noise on seasonal fish chorusing

引用

ICES Journal of Marine Science 2025年第4期82卷

作者： Siddagangaiah, Shashidhar Fang Chen, Chi- Hu, Wei-Chun Akamatsu, Tomonari Pieretti, Nadia Department of System Engineering and Naval Architecture National Taiwan Ocean University Keelung 202301 Taiwan Underwater acoustic laboratory Department of Engineering Sciences and Ocean Engineering National Taiwan University Taipei 106319 Taiwan Ocean Policy Research Institute the Sasakawa Peace Foundation Tokyo 105-0001 Japan Independent Researcher via del Turismo 44 Recanati 62019 Italy

Offshore wind farms have recently emerged as a renewable energy solution. However, the long-term impacts of wind turbine noise on fish chorusing phenology are largely unknown. We deployed a hydrophone 10 m from a foremost turbine in Taiwan situated at the Miaoli offshore wind farm (Taiwan Strait) for two years to investigate sound levels and assess the potential influence of turbine noise on seasonal fish chorusing patterns during 2017 and 2018. Wind turbine noise (measured in the 20-250 Hz frequency band) was significantly higher in autumn and winter (mean SPL: 138-143 dB re 1 μPa) and was highly correlated with wind speed (r = 0.76, P < 0.001). During both years, fish chorusing exhibited a consistent trend, that is, beginning in spring, peaking in summer, decreasing in autumn, and absent in winter. Our results show the noise from a single turbine during the two-year monitoring period did not influence the seasonal fish chorusing (r = -0.17, P ≈ 1). Since the offshore wind farm installations are growing in magnitude and capacity across the Taiwan Strait, this study for the first time provides baseline operational sound levels and an understanding of the fish seasonal vocalization behavior at the foremost turbine of the first wind farm in Taiwan. The results presented here provide useful insights for policymakers and constitute a reference starting point for advancing knowledge on the possible effects of wind turbines on fish chorusing in the studied area. © 2024 The Author(s).

关键词： behavioral assessment marine environment monitoring marine soundscape offshore windfarm

来源：评论

学校读者我要写书评

暂无评论

Numerical analysis of immersed finite cylindrical shells using a coupled BEM/FEM and spatial spectrum approach

引用

Applied Acoustics 2009年第2期70卷 256-266页

作者： Liu, Chia-Hung Chen, Pei-Tai Department of System Engineering and Naval Architecture National Taiwan Ocean University No. 2 Beining Road Keelung 20224 Taiwan

This study numerically analyzes submerged cylindrical shells using a coupled boundary element method (BEM) with finite element method (FEM) in conjunction with the wave number theory, in which the spatial Fourier transform of surface velocity for cylinders is directly related to pressure in a far field. The acoustic loading is formulated using a symmetric complex matrix derived from a boundary integral equation where the symmetry is based on an acoustic reciprocal principle for surface acoustics. In this formulation the acoustic loading matrix is a large acoustic element whose degree of freedom is connected to the normal displacement of the vibrating structures. The coupled BEM/FEM equation is a banded, symmetric matrix, and thus its bandwidth can be minimized using a proper algorithm. This formulation significantly increases numerical efficiency. The computed normal velocity is thus transformed to wave number representation to examine acoustic radiation. A finite plane cylindrical shell, without attached stiffeners, and a shell with internal ring stiffeners are chosen to demonstrate the present analysis procedure. The far field pressure computed directly from the integral equation and predicted by wave number theory correlates closely with increasing vibrating frequency. Meanwhile, the influences of the internal ring structures on acoustic radiation are examined using the wave number theory, which helps in understanding how internal structures influence radiated noise. © 2008 Elsevier Ltd. All rights reserved.

关键词： Finite element method

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：