bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detailed Structural Design
Authors: Lehmann Eike 
Published: April 2017

Abstract
This article deals with detailed structural design of the steel work of seagoing ships. Welding technology has the most important influence in the design of the structural design of the entire steel structure of seagoing ships. The dimensioning of the thickness of plates and the reinforcement with stiffeners, beams, and knees can be carried out with simple design formulas, based on the classical beam and plate theory and notified by the rules of the classification societies. This approach to the detailed structural design is still common practice today in order to create the initial structural design. The simple design formulas are also essential for preparing the numerical models for direct structural analyses with FEM for defining the final dimensions of the plate thicknesses, reinforcements, and so on. In this context, it is very important to know the principal functions of the local structural details, to provide an inside into the structural behavior and the strength and effectiveness of the structure.
Global Hull‐Girder Response (Quasi‐Static, Prismatic Beam Models)
Authors: Varsta Petri , Remes Heikki , Romanoff Jani 
Published: April 2017

Abstract
In the conceptual design phase of a ship, it is important to optimize the structural elements of the hull girder with respect to minimum weight. This enables maximization of the payload. This design task requires deep understanding of the hull‐girder response under operational loading including still water and wave loads. The quasi‐static response of a prismatic beam is preferred due to the shortage of time. The classical analysis exploits the bending and torsion theory presented within the field of solid mechanics. In addition, it is important to take into account the special features of the hull girder due to the structural topology of this dynamically loaded thin‐walled, lightweight structure.
Underwater Noise Radiation, Mechanisms, and Control
Authors: Grushetsky Igor V. , Kalyu Valeriy A. , Shlemov Yuri F. , Tarovik Vladimir I. 
Published: April 2017

Abstract
Essential aspects of underwater noise (UN) from ships are addressed. The importance of ship UN problems has been emphasized by the introduction of UN regulations embracing all types of ships. The physical models of ships used in the investigations of the UN‐generation processes and engineering estimations are described. Among the issues addressed are shipboard machinery treated as noise sources, paths of vibrational energy propagation from sources, and radiation into water; methods for measuring the UN from ships, including measurement accuracy estimates, as well as techniques for revealing the major UN sources. Key measures to be taken for meeting the ship UN requirements are presented.
Ship Noise Control
Authors: Fischer Raymond W. , Bahtiarian Michael A. 
Published: April 2017

AbstractThis article is intended to provide a basic understanding and overview of the critical factors controlling habitability noise onboard vessels. It is intended to assist the marine community—shipyards, naval architects, marine engineers, regulators, and owners—in addressing issues and important design parameters related to generation and control of shipboard noise. It includes a description of noise‐generating mechanism, specifics on noise sources in ships, information regarding noise transmission through the hull structure, an overview of methods used for noise analysis, and noise control during the design stage or during modernization. There is a discussion of inspection and compliance testing. With the proper understanding of how noise is generated, controlled, and measured, ships can be delivered to various noise criteria in a straightforward, economic, and optimal manner.
Ship Vibration, Global, and Local Modes
Authors: Mumm Holger 
Published: April 2017

AbstractThis article is intended to provide an overview of ship structural vibration and its effects on human comfort and structural integrity. It addresses natural and forced vibration phenomena as originating from the action of time‐variant impulsive and continuous vibration excitation forces on global and local hull structures. After an introduction into important terms, principles, and concepts in the field of ship vibration, the global and local vibration modes as excited by the major sources of ship vibration are addressed. This includes seaway‐induced whipping and springing vibration and structural oscillations forced by periodic vortex shedding and the different kinds of continuous vibration excitations originating from ship main engines and propellers. For an easier understanding of the excited natural vibration modes and operational deflection shapes, the underlying vibration excitation force mechanisms are briefly described as well. Focus is on ship vibrations as encountered in engineering practice. Guidance is provided, how ship vibration phenomena can be investigated during the ship's design phase and which vibration countermeasures can be expected to be effective.
Static and Dynamic Shaft System Alignment
Authors: Smith Andrew 
Published: April 2017

Abstract
This chapter deals with design of the low speed shaft line of marine installations, and what this design should aim to achieve, so as to contribute to reliable operation. The challenges of achieving satisfactory alignment varies from ship type to type and these are discussed. Numerical analyses that are undertaken to arrive at an acceptable design are examined , together with the issues that are required to be considered in these computations, such that the design constraints are achieved.
Alignment Procedures are reviewed to ensure that the shaft line and components are constructed and installed in a manner to achieve the design requirements.
Practical Aspects of installing the shaft line and components are discussed. Pros and cons of measurement techniques are explored suggesting how correlation of the installed system with the design conditions are achieved and recorded.
Measurements and Structural Monitoring
Authors: Storhaug Gaute 
Published: April 2017

AbstractModel tests and hull monitoring can be used to measure wave‐induced hull girder loads, which are used to assess the risk of fatigue cracking and hull girder collapse. Although, the objective of model tests and hull monitoring may differ, they are valuable supplements to numerical analysis. More reliable and realistic results can be obtained, and physical aspects not covered by the idealized numerical codes can be included. Example of such is whipping and springing vibrations, which are difficult to incorporate in hydroelastic analysis. Hull monitoring is, however, not limited to hull girder loads and can include any sensor onboard covering any need.Measurements of hull girder loading are often regarded as the “truth,” but there are several uncertainties. It can be stated that the numerical analysis can never be better than the measurements, which have been used in the validation; hence, efforts should be made to limit the uncertainties in the measurements.Model tests and hull monitoring are not frequently used. Significant initial costs, lack of standardization, poor data quality, unawareness, and substandard suppliers contribute to this. The benefit during the operational life can by far exceed the costs related to model tests during the design phase or installation costs of the real vessel. Preplanned and proper data assessment is a prerequisite to bring value and decision support to the stakeholders.
Propeller Manufacture and Tolerances
Authors: Janssen André , Leever Sylvia 
Published: April 2017

Abstract
This article describes the manufacturing of ship screw propellers. A fixed pitch propeller (FPP) and different parts of a controllable pitch propeller (CPP) are made by casting and subsequent machining. The most commonly used material is NiAl‐bronze, although also stainless steel is used. Based upon a casting design, a sand mold is made and the liquid metal is poured into the mold. After solidification, the part is taken out of the mold and a visual check is made before the rough casting is measured. An intermediate balancing and dye penetrant investigation is made after pre‐grinding of the casting. If any casting defects are present and permitted to repair, these are repaired before final grinding and polishing. Grinding and machining techniques, including NC simulation, are described for the different parts of the propeller. The final product must meet the specified dimensions within the allowed tolerances. Depending on the purpose of the vessel, a different (tighter) tolerance class than ISO 484 may apply.
Inviscid Hydrodynamics
Authors: Manasseh Richard 
Published: April 2017

Abstract
The fundamentals of fluid dynamics are introduced in a context relevant to maritime engineering. The properties of fluids and definitions of features of fluid flows are given. The fundamental laws of fluid motion are explained, focusing on the laws of conservation of mass and momentum. An integral form of the momentum equation, Bernoulli's equation, is derived and its use is demonstrated. The concepts of vorticity, stream function, and velocity potential are introduced. These lead to the powerful principle of potential flow. Although all these fundamentals neglect the viscosity of the flow, and hence drag due to boundary layers, potential flow is nonetheless an immensely helpful design tool and its usefulness in engineering is illustrated.
Main Propulsion Arrangement and Power Generation Concepts
Authors: Stapersma Douwe 
Published: April 2017

AbstractAn overview is given of mechanical, electrical and hybrid propulsion arrangements. The relation between propulsion concepts and power generation is explained and elaborated in energy flow diagrams. A general procedure for analyzing propulsion and power generation concepts is presented, using energy conversion effectiveness and based upon a selection of operational modes and a mission profile reflecting the use of those modes. Potential matching problems when switching between propulsion modes are identified and possible solutions given.
Rotational Waves, Wave Turbulence, and Wave Attenuation
Authors: Badulin Sergei I. 
Published: April 2017

AbstractElements of dynamics of rotational water waves are given in their connection with the problem of wave attenuation. Both classic results like the rotational Gerstner waves and recently found generalization of these waves–the Ptolemaic flows–are presented.Theory of wave turbulence starts with the Zakharov's equations for weakly nonlinear water waves. The Hasselmann (kinetic) equation as a basis of statistical description of wind‐generated water waves is introduced and its stationary solutions for direct and inverse cascade, the so‐called Kolmogorov–Zakharov ones, are presented. Recent results on self‐similarity of wind‐driven seas finalize the article.
Frequency‐Direction Spectra of Wind‐Generated Gravity Waves
Authors: Donelan Mark A. 
Published: April 2017

Abstract
The frequency‐direction spectra of wind‐generated surface gravity waves are summarized in terms of the spectral peak frequency and the stage of wave development (ratio of wind speed at 10 m height to wave phase speed at the spectral peak frequency). The spectra exhibit an enhanced peak, an equilibrium range at frequencies higher than twice the peak, and increased directional spreading at lower and higher frequencies than the peak. Five parameters completely describe the spectra: four are functions of the stage of wave development and the fifth depends on relative (to the peak) frequency. The spectral formulae provided apply in intermediate and deep water. Marine and offshore engineers will find the formulae useful for design and operational calculations. They require only the wind vector and the spectral peak frequency as input.
Generation of Waves by Wind
Authors: Hristov Tihomir 
Published: April 2017

Abstract
The physical mechanism responsible for the existence of ocean waves is described. The wind‐generated ocean surface waves occur from the coupling of two random media, the turbulent atmospheric flow and the compliant ocean surface beneath. The physical analysis here relies on the approximation of surface waves having a small slope, commonly guaranteed in the ocean by the phenomenon of wave breaking. As the wave‐coherent motion in the air is at the core of the wind–wave generation, the dynamic and statistical patterns of that motion are outlined. The dynamic significance of the critical height, a location in the air flow where the mean wind speed matches the phase speed of an underlying wave mode, is pointed out. The article focuses on the characteristic features of the wave‐coherent air flow, such as the discontinuity of the phase at the critical height, which constitute testable predictions of the theory. Experimental evidence in support of wind–wave generation through wave‐coherent flow is presented. Earlier empirical studies on wind interaction with the aerodynamically rough ocean surface are briefly discussed.
Finite‐Depth and Shallow Water Waves
Authors: Groeneweg Jacco , van Dongeren Ap 
Published: April 2017

AbstractWaves travel from deep water through intermediate depths into shallow regions, where they encounter the coastline, possibly with islands, headlands, estuaries, tidal flats, reefs, and harbors. In the shallow water region, the wave propagation is complex. Horizontal variations in the bathymetry cause shoaling, refraction, wave‐energy redistribution, and breaking, whereas horizontal variations in amplitude cause diffraction. Obstacles cause the waves to reflect. These shallow water processes have been described in detail.In addition, two typical wave‐induced aspects in the nearshore area have been highlighted. Firstly, gradients in the so‐called radiation stresses act as a force that may generate a set‐up or set‐down of the water level or a current. Secondly, incident waves force the so‐called infragravity waves, which are released from the short‐wave groups in the shoaling and breaking process.
Wave Effects in the Upper Ocean
Authors: Qiao Fangli , Huang Chuan Jiang 
Published: April 2017

Abstract

Ocean surface waves can regulate the vertical mixing process of the upper ocean through wave breaking and wave‐turbulence interaction, and induce other motions including the Stokes drift and Langmuir cells. In ocean circulation models, surface waves reduce the sea surface temperature (SST) and increase the subsurface temperature, thereby deepening the upper ocean mixed layer and sustaining a reasonable seasonal thermocline in the summertime. In atmosphere–ocean‐coupled models, in contrast, surface waves affect the SST mainly
via
strong atmosphere–ocean coupling especially in the equatorial oceans. Surface waves decrease the SST in the eastern basin and increase it in the western basin, which contribute to the seasonal cycle and interannual variation of the SST. On the other hand, surface waves can modify currents and circulations of the upper ocean
via
wave‐induced strong mixing and Stokes drift. In the coastal and shallow seas, surface waves affect significantly sediment distribution and resuspension and modify the turbidity of the sea water and the seabed form. The combined effects of wave and tidal mixing contribute to sustain typical temperature profiles in the coastal regions.
Internal Waves
Authors: Jones Nicole L. , Ivey Gregory N. 
Published: April 2017

AbstractInternal waves are a ubiquitous feature in the ocean. They are of considerable importance in the marine environment as they can both create currents and drive turbulent ocean mixing. Nonlinear internal waves (NLIWs) or solitons induce large vertical displacements of constant density (isopycnal) surfaces of O(100 m) and strong horizontal velocities of O(1–2 m/s) as they propagate. Such large displacements and velocities, in turn, affect nutrient mixing and biological productivity, sediment resuspension, the propagation of acoustic waves, and marine and offshore engineering operations. As NLIWs are potentially hazardous to subsea oil and gas operations, the ability to predict the occurrence and arrival of these waves is necessary for both cost‐effective operation and safety. Despite the considerable body of knowledge about these waves, the prediction of NLIWs remains a very challenging issue and the subject of ongoing research. This article first discusses the theory of internal waves. It then focuses on the generation, propagation, and dissipation of internal tides. Finally, it considers the implications of internal tide dynamics for engineering design and operation in the offshore environment.
Phase‐Resolving Wave Modeling
Authors: Chalikov Dmitry 
Published: April 2017

Abstract

Phase‐resolving modeling of sea waves is the mathematical modeling of surface waves including explicit reproduction of the sea surface and velocity field evolution. The general approach is based on equation of potential motion with a free boundary. Conformal transformation of coordinates is the most effective method of solution of two‐dimensional (
x–z
) periodic problem. For three dimensional models, several different approaches have been developed: boundary integral equation method (BIEM), method based on expansion of velocity potential in a vicinity of surface [high order spectral method (HOSM)], and method based on direct solution of three‐dimensional equation for velocity potential. These methods do not compete with each other because all of them have their advantages. The brief descriptions of each method are given as well as the examples of theirs applications. The investigations of nonperiodic problems are based on a direct solution of equation for velocity potential. The methods of including in the models of algorithms for parameterization of energy input and dissipation are discussed.
Delivery Trials
Authors: van den Boom Henk 
Published: April 2017

AbstractShips are subjected to delivery trials to assess their performance and to evaluate this against the regulatory requirements and the specifications in the new building contract. Depending on the ship type, delivery trials comprise speed/power performance as well as more detailed characteristics such as cavitation, hull‐pressure fluctuations, and noise and vibration. Procedures for trial conduct, measurements, and analysis to derive at reliable results acceptable to all parties involved are described.
Statistical and Theoretical Prediction Methods
Authors: van Hees Martin T. 
Published: April 2017

AbstractIn this article, the basic hydrodynamic concepts of ship resistance and propulsion are introduced with a focus on power prediction in the early stages of design. The historical developments in ship performance prediction and the role of methodical series of ship hulls and propellers in power prediction are discussed in detail. Ship propulsion is separated from its basic components, and hull geometry aspects that are relevant to resistance and propulsion are introduced. Specific attention is paid to the developmental approach toward statistical prediction methods, their application domain, and their limits. Finally, the application of these methods within the daily practice of ship design and how to use proprietary model test and sea trials data in order to improve prediction accuracy are discussed.
Maneuvering Experiments
Authors: Yasukawa Hironori 
Published: April 2017

AbstractThis article describes the experimental techniques used to predict ship maneuvering including model captive, model free, and full scale. Full‐scale trials are conducted to confirm the performances of a new ship and to check machineries and equipment onboard at the final stage of the building. Procedures of three trials for the turning, zigzag, and stopping tests are explained in detail with relation to important performances including course keeping, turning, and stopping abilities. The advantage of free‐running model tests is to be able to predict the full‐scale ship maneuverability directly from the test results. The spiral and the reversed‐spiral tests are described together with the special features of course stable and unstable ships. In the captive‐model tests, the model that is restrained to the testing device through the force balance is enforced to make predetermined motions, and the hydrodynamic forces acting on the model in the motions are measured. Measured data are analyzed on the basis of the motion equations together with the mathematical models of hydrodynamic force representations. Testing facilities and data analyses with respect to a rotating‐arm or circular‐motion and planar‐motion‐mechanism tests are explained.
Numerical and Hybrid Prediction Methods for Ship Resistance and Propulsion
Authors: Raven Hoyte C. 
Published: April 2017

Abstract
This article reviews computational methods to predict the required propulsion power and propeller rotation rate of a ship at given speed. RANS (Reynolds‐averaged Navier–Stokes) methods for predicting the full‐scale viscous free‐surface flow around the ship and the resistance are described, and the numerical uncertainty and comparison error of current methods is assessed. Today, for model scale resistance both can be limited to a few percent with good codes and relatively dense grids; however, more attention is desired for appended ship hulls and effects of hull roughness. Methods to compute the propeller operation behind the ship are described; RANS methods coupled with potential‐flow propeller models and fully viscous approaches using sliding interfaces. Here, less experience is available and computed results show larger deviations. Progress is desired as the present prediction accuracy seems not generally sufficient and the reliability is still less than that of predictions based on model tests.
Dynamic Positioning
Authors: Perez Tristan 
Published: April 2017

AbstractShip and mobile offshore unit operations require accurate positioning. To date, it is difficult to conceive of these operations without ship‐motion control. This brief article describes the main characteristics and the design principles associated with dynamic positioning (DP), a motion control technique that uses feedback control to achieve vessel position and heading regulation by means of the propulsion system. This article reviews the basic architecture of a DP system and outlines the estimation and control design strategies commonly used. It also discusses the requirements of reliability and safety for different operations.
Historical Development of the Offshore Industry
Authors: Schmidt Victor A. , Crager Bruce , Rodenbusch George 
Published: April 2017

Abstract
The oil and gas industry finds and develops offshore oil and gas fields in three major stages: exploration, drilling, and production. Specialized engineering is required and has been applied throughout each of these stages resulting in the industry's steady advance into deeper water and more challenging environments. The advances in engineering are best seen in the structures and technologies that have been applied in the vessels designed for use on and in the water, in the new materials developed to meet harsher conditions, and in the control systems developed to guide the flow of fluids from deep in the earth, through the water column, and into the platforms and floating production systems that gather and process the production, so it can be sent to market. The engineering challenges continue to evolve, and the solutions that are developed set the stage for industry's next advance into the ocean's depths.