Volker Bertram

Volker Bertram
dnv gl

About

111
Publications
25,029
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,127
Citations
Citations since 2017
6 Research Items
529 Citations
2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
Introduction
Skills and Expertise

Publications

Publications (111)
Article
Full-text available
Wind propulsion is well known and has propelled ships for millennia. However, with the advent of fossil-fuel powered ships, wind energy lost its importance for cargo transport almost 100 years ago. Rising fuel prices and a society being more aware of the consequences of CO2 emissions fuels the revitalization of this energy source and a variety of w...
Article
Full-text available
This paper surveys techniques for distance learning, discussing characteristics, suitability and cost aspects of various digital technology option. While the techniques and the employed software are generic, the discussion is in the maritime context, with focus on technical and regulatory content and a scattered trainee base, as typical for a class...
Article
Full-text available
The paper discusses key trends in ship design, ship building and ship operation and extrapolate those trends into the future. Fast and unconventional craft will play a minor role only in this scenario. In fact, trends are towards lower speed and simpler hull shapes, wind assisted technologies and propulsion improving devices. Cleaner fuels, most no...
Conference Paper
The paper describes an industry project for the development of an avantgarde power trimaran for Tiger Yacht Management being built at composite builder McConaghy Boats. The aim was to explore possible refinements together with Frers Design using advanced engineering techniques. The paper outlines the process (involving concept exploration, formal o...
Conference Paper
This paper surveys applications of CFD (computational fluid dynamics) to the design of submarines and autonomous underwater vehicles (AUVs). Platform design has progressed from model test based and empirical approaches to simulation-based design and in some cases formal optimization. This paradigm change results consistently in significantly better...
Conference Paper
Full-text available
Containership operators are confronted with a multitude of proposals for fuel saving measures and even more promises. Actual savings are generally much lower than quoted numbers in advertisement material and even scientific publications. Reasons for discrepancies are discussed and some guidelines for selecting suitable measures are given. There are...
Conference Paper
This paper looks at selected applications of advanced hydrodynamic simulations in the offshore oil & gas industry. Progress in computational techniques and hardware has opened the door to more advanced simulations. But do more advanced field equations really lead to better results? Or should we employ proven potential-flow codes along with the engi...
Conference Paper
Full-text available
The paper describes a numerical approach to predict added power requirements in waves. An introduction describes the importance of this keystone technology for energy efficiency, addressing correct definition of operating point and sea margin, routing optimization, and hull performance monitoring. Added resistance and in general drift forces and mo...
Article
The paper gives a survey of knowledge-based systems KBS for ship design and ship operation over the past three decades. While there are several commercial applications of KBS in ship operation, applications in ship design have remained almost exclusively in the academic stage.
Chapter
This chapter highlights the ship maneuvering that comprises course keeping, course changing, track keeping, and speed changing. Maneuvering requirements are a standard part of the contract between shipyard and shipowner. International Maritime Organization (IMO) regulations specify minimum requirements for all ships, but shipowners may introduce ad...
Chapter
This chapter discusses the ship vibrations that consider the ship hull and its structural members as elastic structures. Vibrations are important in the structural design due to the following design trends—lightweight construction, arrangement of living and working quarters near the propeller to optimize stowage space, high propulsion power, small...
Chapter
This chapter deals with the experimental approaches—towing tanks and experimental set-up, resistance test, method of Hughese–Prohaska, Geosim method of Telfer, and propulsion test. The propeller increases the flow velocities in the aftbody of the ship which increases frictional resistance. The propeller decreases the pressure in the aftbody, thus i...
Chapter
This chapter deals with propulsion and argues that ships are predominantly equipped with “simple” screw propellers. Propellers turning clockwise seen from aft are “right-handed.” In twin-screw ships, the starboard propeller is usually right-handed and the port propeller, left-handed. The propellers are then turning outwards. The propeller geometry...
Chapter
This chapter examines the seakeeping of ships with respect to the different issues and tools to predict ship seakeeping. Seakeeping is determined as representation of the natural seaway as superposition of many regular waves, computation of the ship reactions of interest in these harmonic waves, and addition of the reactions in all these harmonic w...
Chapter
This chapter provides an overview of the problems and approaches that are faced during model tests. It also defines the prediction of ship hydrodynamic performance, which can be broken down into the general areas of resistance and propulsion, seakeeping and ship vibrations, and maneuvering. The basic idea of model testing is to experiment with a sc...
Article
Ship design has always been primarily an experience-based skill. While this is still true to some extent today, we increasingly rely on "virtual experience" drawn from computer simulation. The rapid development of fast and unconventional ships since the 1980s would have been impossible without advanced simulation technology. Simulation is especiall...
Book
The author has provided the reader with comprehensive coverage of ship hydrodynamics with a focus on numerical methods now in use. The book provides a global overview of experimental and numerical methods for ship resistance and propulsion, manoeuvring and seakeeping. As boundary element techniques are now in standard use, these are covered in suff...
Article
This paper surveys developments in Computational Fluid Dynamics (CFD) applications for maritime structures (ships, propellers, and offshore structures) over the past decade. Progress is significant in integrating the process chain, particularly more automated model generation. Increased hardware power and progress in various aspects of the flow sol...
Article
This paper surveys developments in Computational Fluid Dynamics (CFD) applications for maritime structures (ships, propellers, and offshore structures) over the past decade. Progress is significant in integrating the process chain, particularly more automated model generation. Increased hardware power and progress in various aspects of the flow sol...
Chapter
The paper discusses the background of various seakeeping tools, ranging from strip theory to sophisticated 3d Navier-Stokes solvers, in the perspective to sketch a sort of users guideline for efficient exploitation. In fact, there is no approach that is suited for all seakeeping applications, but their associated advantages and disadvantages should...
Article
The paper surveys the role of modern computer simulations to support the design of ships. At the centre of most efforts is the quest for fuel efficiency and today also reduction of emissions. However, designs need also to consider safety and for some ships comfort aspects. The employed simulation techniques are frequently the same and several examp...
Article
Full-text available
Rational assessment of stern slamming of a large twin-screw LNG carrier comprised prediction of hydrodynamic impact loads and their effects on the dynamic global structural behaviour of the hull girder. Linear theory obtained regular equivalent waves that caused maximum relative normal velocities at critical locations underneath the ship's stern. R...
Article
In this work the dynamic responses of bonded top hat stiffened panel have been studied by using finite element analysis model (Abaqus). A symmetrical 2D model was performed and used in the simulations. In the first part, dynamic behavior and impact speed effects at such composite structure have been studied. In the second part, other simulations we...
Conference Paper
Full-text available
The paper surveys engineering options to save fuel in ships, both in design and operation. Both propul-sion and on-board consumers are discussed. Propulsion power depends on resistance and propulsive efficiency. Here, the main options are given, following a systematic breakdown of the individual resis-tance components and the efficiency losses at t...
Conference Paper
Full-text available
The paper surveys hydrodynamic options to reduce emissions by making ships more fuel efficient. The discussion covers modern techniques for hull and appendages design and trim optimization in operation. The approach for formal lines optimization is described, including parametric hull modelling, computa-tional fluid dynamics, and optimization and s...
Article
Full-text available
Simulation-based design increasingly replaces traditional experience-based design. This article gives an overview of techniques now used in advanced industry practice, with particular focus on navy applications. The article covers the basics of the techniques, illustrating approaches and state of the art with applications taken from the experience...
Article
The design of ships and offshore structures is increasingly supported by sophisticated analyses. Traditionally, this design has been based on experience. This is still true to some extent, but increasingly we rely on ‘virtual experience’ from dedicated and well chosen simulations. Scope and depth of these simulations guiding our decisions in design...
Article
Dans ce travail, on a étudié le comportement mécanique de différents types de raidisseurs composites collés sur une plaque sandwich sous différents chargements statiques. Dans la première partie, on a réalisé plusieurs simulations numériques qui nous ont servi à comparer le comportement mécanique de différentes géométries de raidisseurs : Ώ , Ί , 1...
Article
This paper describes the background of the seakeeping code GL RANKINE. The code determines motions and loads of ships in seaways. The zero-order (steady) potential due to steady ship motion is completely considered. The seakeeping contributions are considered up to first order, i.e. for the contributions depending linearly on wave amplitude. Result...
Article
Traditionally autonomous underwater vehicles (AUVs) have been built with a torpedo-like shape. This common shaping is hydrodynamically suboptimal for those AUVs required to operate at snorkeling condition near the free surface. In this case, the wave resistance associated to the wavy deformation of the sea surface induced by the motion of the platf...
Article
The fluid structure interaction is simulated during the impact of a 2-d wedge on a water surface. The analysis combines the assumption of small displacements for the ideal fluid and the solid with an asymptotic formulation for accurate pressure evaluation on the wet surface boundary. Wedge deadrise angles β above approximately 30° do not fulfill th...
Article
The survey of marine Unmanned Surface Vehicles (USVs) covers both actually built and projected USVs. Most USV developments are found in the USA. USVs remain so far limited to small to medium vessels with limited autonomy.
Article
SUMMARY An overview of computational tools for the hydrodynamic design of fast ships is given. The individual techniques are discussed, and suitable tools are recommended. Trends are discussed and illustrated by some advanced pioneering applications.
Article
The general development towards simulation-based design has been supported and in some cases even driven by modern classification society work. Advanced finite-element analysis has long been part of the services of classification societies. However, more recently the scope and depth of simulations at Germanischer Lloyd have developed rapidly and a...
Conference Paper
A method for the prediction of seakeeping behaviour of sailing yachts has been developed. It is based on linear strip theory with some non-linear extensions. The method is capable to take into account heeling and yawing yacht hulls, yacht appendages and sails. The yacht's response amplitude operators (RAO) and added resistance in waves can be predi...
Article
The survey discusses trends including high-speed vessels including new hybrid concepts, unmanned drones, reduction of crews, all-electric ship, podded drives and stealth. The literature survey focuses on developments of the past three years and was developed within the framework of a recent and continuing study for the French Navy.
Article
Full-text available
The design of a concrete AUV for oceanographic research in the Mediterranean revealed the lack of general design guidelines for AUVs. During a cooperation phase between AUV designers and naval architectural hydrodynamicists some design guidelines for AUVs were compiled. This compilation exemplifies the design approach, combining empirical estimates...
Article
Full-text available
The required paper is not available any more, but this much more extensive program description is available instead.
Article
Une méthode des tranches pour l'analyse de la tenue à la mer des yachts est actuellement en cours de développement dans le domaine public. Pour ce type de structure, il est indispensable de modéliser les ailerons. La théorie pour prendre les ailerons en compte de façon semi-analytique est présentée et une application démontre l'influence des ailero...
Conference Paper
A fully 3-D Rankine panel method in the frequency domain is validated for local pressures and global rigid-body motions. The method is linearized with respect to wave amplitude. The steady flow contribution is captured completely by solving the fully nonlinear wave-resistance problem first and linearizing the seakeeping problem around this solution...
Conference Paper
Ship design changes from experience-based design to first-principle, simulation-based design. The scope of analyses in modern ship design is demonstrated showing industrial and recent research applications, not only in classical structural and fluid mechanics, but also in discrete event simulations as applied in cargo handling and ship evacuations....
Conference Paper
An overview of techniques, collectively grouped under the label 'artificial intelligence', for low-crew or even unmanned ships is given with special focus on navy ships. Knowledge-based systems, machine vision, speech and gesture interpretation, distributed intelligence are discussed with recent research applications worldwide given to illustrate p...
Article
Full-text available
This paper results from part of the work performed in sub-project II.1 of InterSHIP, a European R&D project funded under the European Commission's Sixth Framework Programme for Research and Technological Development. (Project no: TIP3-CT-2004-506127)
Conference Paper
This paper presents a study of fluid structure interaction during the impact of a ship on a water surface. The analysis combines the assumption of small displacements for the ideal fluid and the solid with an asymptotic formulation for accurate pressure evaluation on the wet surface boundary. A fluid-heat analogy is used to obtain the regular displ...
Article
Related transport engineering sciences show spectacular progress in automation reviving a discussing of unmanned ships using Artificial Intelligence technologies particularly for combatants. The nautical tasks could be largely automated and the commercial expert systems for automatic navigation including collision and grounding avoidance are on the...
Article
Simple design formulae for resistance prediction for fast semi-displacement monohulls are derived using Artificial Neural Nets. The formulae were derived from curves based on database evaluation of the Hamburg Ship Model Basin.
Article
The authors attempt to express the environmental impact of ships in one metric to allow engineering comparison or optimization of ships in terms of the environmental impact. Emissions are shown to be the most important environmental impact factor for ships. The model includes only emissions in the quantitative metric, but other factors are discusse...
Article
Typical productivity parameters based on compensated gross tonnage (CGT) per man-hour or man-year are shown to be insufficient in understanding and controlling competitiveness. Competitiveness is based on time, cost and quality. For cost competitiveness, an in-depth model for controlling competitiveness is presented. The model considers various fac...
Article
The cavitating flow around a three-dimensional foil is simulated using a commercial RANSE solver with a simplified cavitation model. The cavitating flow is numerically treated as two-phase flow using an interface-capturing method. The transport equation is modified by a source term describing the growth and collapse of cavitation bubbles. The appro...
Article
The Gothenburg 2000 was an international benchmark workshop for computational fluid dynamics applied to ship flows. Test cases were three modern hull forms. One case without a free surface focused on turbulence modeling, whereas wave prediction was of interest for the other two. Of the free-surface cases, one had an operating propeller. For the fir...
Article
A panel method for the calculation of fully non-linear two-dimensional potential flow about hydrofoils close to a free surface is presented. Higher-order panels are used on the free surface, and the staggered grid method enforces the radiation condition. A case study involving a NACA-0012 hydrofoil is presented, showing that the method is robust an...
Article
The two-dimensional unsteady flow about a hydrofoil moving beneath a free surface is studied by an inviscid model with embedded vorticity, generated through a suitable unsteady Kutta condition. The mathematical problem is recast in terms of boundary integral equations for which an accurate and efficient solver is developed and coupled with a Runge-...
Chapter
This chapter focuses on the ships equipped with propellers. Any propulsion system interacts with the ship hull. The flow field is changed by thehull that is usually upstream located. The propulsion system changes, the flow field at the ship hull. These effects and the open-water efficiency of the propeller determine the propulsive efficiency.
Chapter
When designing cargo ships, the naval architect usually knows the main dimensions (length L, width B, draught T, block coefficient CB) and the longitudinal position of the centre of buoyancy. A minimum KM value is also frequently specified. However, for ships that are not affected by freeboard regulations, the designer often has relative freedom to...
Chapter
Prediction methods should be calibrated using data from comparable ships. This allows the selection of appropriate procedures for a certain ship type (and shipyard) and improves the accuracy. Prediction of weights and centers of mass is an essential part of ship design. An accurate estimate is necessary for quoting prices. A global price calculatio...
Chapter
Main dimensions decide many characteristics of a ship, for example, stability, hold capacity, power requirements, and economic efficiency. Therefore, determination ofmain dimensions and ratios forms an important phase in the overall design of a ship. The length L, width B, draught T, depth D, freeboard F, and block coefficient CB should be determin...
Chapter
Most design problems may be formulated by determining a set of design variables (for example, the number of ships, individual ship size and speed in fleet optimization, main dimensions and interior subdivision of ship, scantlings of a construction, characteristic values of pipes and pumps in a pipe net). The design variables are subject to certain...
Chapter
This chapter describes some propulsion systems. Rudder propellers (slewable screw propellers)—with or without nozzles—are not just a derivative of the well-known outboarders for small boats. Outboarders can only slew the propeller by a limited angle to both sides, while rudder propellers can cover the full 360°. Slewing the propeller by 180° allows...
Article
The paper presents data of theoretical and experimental (on-site and laboratory) studies of the effect of sea-water density inhomogeneity on the hydrodynamics of drifting icebergs. On the basis of previously obtained theoretical relationships, the coefficients of wave resistance are calculated for a body of varying submergence depth that crosses th...
Article
The problem of an optimization algorithm being limited to continuous variables in ro/ro ship optimization is solved by introducing an additional continuous variable. The optimization determined then a theoretical optimum parameter combination for the continuous variables. A subsequent optimization determined the actual optimum that could be realize...
Article
The main dimensions decide many of a ship's characteristics. Therefore determining the main dimensions and ratio forms a particularly important phase in the overall design. The alternatives based on more modern hull forms of ship design and the issue of formal optimization of the main dimensions are discussed.
Article
A ship can be considered as a vertical foil of very short span. For a steady yaw angle, one would certainly enforce some kind of Kutta condition in a potential flow computation. The Kutta condition requires that at the trailing edge, the pressure are equal on both sides. Four antisymmetric potentials are solved in a Rankine panel method which uses...
Article
A 3-d seakeeping code uses first-order Rankine panels with special numerical integration on the ship's hull and Rankine point source clusters above the free surface. The code computes the motions of the ship in regular waves of small height (linearized). The steady flow is captured without simplification by solving the fully nonlinear wave-resistan...
Article
Full-text available
The development of any design support system (DSS) is complex. It depends on the task being supported and the organization that is going to use it including its present design practices. This paper describes the initial steps in developing a DSS for marine propeller design based on the process carried out at HSVA(Hamburg Ship Model Basin). We follo...
Article
In the studies carried out the benchmark test showed that strip methods were valid only to approximately F"SUB n" 0.4. End effects are important for ships with transom sterns and should be considered. For practical purposes the high-speed strip method (HSST) is at present the most suitable method for fast ships. CPU time requirements, time-consumin...
Article
In response to the requirement for successful ship design in short sea shipping, a ro/ro Catamaran for trucks and trailers was designed featuring side ramps over the whole length of the ship. This ferry offers additional space for lashing, passage way, and storage of the short sideramps that leads to an overall breadth of 22.0m. The overall length...
Article
Schiffstechnische, logistische und wirtschaftliche Aspekte von Containerschiffen mit mehr als 6000 TEU Kapazität 1968 lieferten der Bremer Vulkan mit der "Weser Express" und Blohm&Voss mit der "EIbe Express" die ersten in Deutschland gebauten Containerschiffe ab. Die baugleichen Schiffe hatten eine Stellkapazität von 736 TEU (20-Fuß-Container). Die...
Article
An overview of hybrid hydrofoils describes designs of the US, Canada, France, Japan, and Germany over the last 20yr. None of the designs has yet been built, but Japan and the USA have building programs for small-scale prototypes. (English summary)
Article
Full-text available
This paper contains simple equations for early stage estimation of the weights of SWATH ship designs, depending on type of structural material and propulsion system selected. The equations are based on regression analysis of actually completed and projected SWATH ship designs up to the early 1990s.
Article
Full-text available
This paper contains simple equations for early stage estimation of all the principal dimensions of SWATH ships including box depth, air gap, hull diameter etc. The equations are based on regression analysis of actually completed and projected SWATH ship designs up to the early 1990s.
Article
Full-text available
This paper contains a number of simplified methods for early stage estimation of the required propulsive power for SWATH ships. At the simplest level, an Admiralty type equation based simply on input displacement and speed is provided. Other methods are given based on a conventional estimate of frictional resistance based on surface area, and resid...

Network

Cited By

Projects

Project (1)