Ship Concept Research Articles

RE-ANALYSIS OF WILLIAM FROUDE’S STUDIES OF PLANING CRAFT

One of William Froude’s lesser-known contributions to the field of Naval Architecture was in conducting some of the earliest studies on planing craft. Froude’s research was prompted by the idea of an inventor, Reverend C.M. Ramus who in 1872 proposed a high-speed ship concept using a flat-bottomed, stepped planing hull. Ramus later suggested the use of this hullform for rocket-propelled rams. Froude conducted towing tests on a model of the Ramus hull, as well as on a model three-point hydroplane concept of his own design. He also derived a solution for the optimum trim angle and minimum resistance of planing craft, using his recently developed formulae for estimating frictional resistance on flat plates and lift forces on submerged plates. Froude’s study demonstrated that Ramus’s ideas were not feasible at the time and the study received very little attention. It was not until the advent of lightweight internal combustion engines, thirty years later, that planing hulls became a reality. In the current paper, the Ramus tests are re-analysed and the data are put into a modern format. Comparisons are provided between the Ramus hull, Series 62 and a planing flat plate. The Ramus concept is shown to have had significantly more drag than would be expected from a planing hull. New model tests explore the effects of the rounded stern of the Ramus hull, and show that this feature significantly increases the resistance. Froude’s derivation of the minimum resistance of planing craft is discussed and contrasted with modern methods for prismatic planing hull resistance prediction.

IMPROVEMENT OF CONDITIONS AND WORKING ENVIRONMENT THROUGH ERGONOMICS INTERVENTION IMPROVED PERFORMANCE AND PRODUCTS QUALITY OF DODOL WORKERS AT PENGLATAN VILLAGE BULELENG RESIDENCY

The success of production is largely determined by the conditions and working environment that will affect the comfort, safety and health of workers. Conditions and working environment did not ergonomic ally designed causing dodol workers in the Penglatan village  Buleleng cannot work optimally. Thus, there should be conducted an ergonomic intervention on conditions and working environment of dodol worker by designing dodol mixer, organizational and working environment with ergonomics interventions through the application of appropiate technology and SHIP concepts approaches. This study was an experimental study with Randomized Pretest and Posttest Control Group Design. This design was a parallel design with number of sample 34 people who were divided into 2 groups they are control and experiment group. Control group that works with the original conditions and working environment totaling 17 peoples and 17 others as the treatment group that works with conditions and working environment that has been improved base on ergonomics. Data were analyzed with a significance level of 5%. The research result showed that there was a decrease in work load between the control and the experiment group 17,11%, decrease in CVL 42,14%, ECPM value was higher than that of ECPT, decrease in musculoskeletal 37,35%, and the tiredness level was34,11%. Work productivity increased from physiological aspect 67,11%, and from economic aspect 179,73%. Based on investment evaluation, NVP value in 5 years was Rp.54.414.450,-, PBP values was 0,26 years less than 5 years and RoI value 19,6% higher than bank interest rate 14%. Laboratory test result showed that there was improvement of dodol quality based on SNI requirement. It was concluded that the improvement of conditions and working environment with ergonomics interventions through the application of TTG and approach of SHIP can improve performance by decreased workload categories, decreased musculoskeletal complaints, decreased fatigue and increase the workers income levels and improve the dodol quality.

Developing a new methodology for evaluating diesel—electric propulsion

In this paper a methodology for the design of ships with a diesel-electric propulsion system, according to the All Electric Ship concept is presented. Taking into account that there is no long and extensive relevant experience for all ship types, diesel-electric propulsion should be selected after careful consideration and thorough evaluation of many technical and economic parameters. This paper offers a step-by-step procedure towards this direction; the discussion is enriched by a case-study of a ship type, where the selection of the proper propulsion system is not straightforward as many parameters have a substantial impact.

Development of Naval Ship Synthesis Model in Concept Design

Naval ship concept design is required not only accurately evaluating the feasibility of projects, but also optimize the technology indexes based on certain algorithm. That means at the foundation of appropriate technology indexes, the cost and risk can be optimized to obtain the preliminary overall project, which can be the design baseline for the subsequent design. The establishing and application pattern of naval ship synthesis model will be discussed in this paper firstly, and overview the development of ship synthesis model for about half the century. Some achievements will be introduced then, which included the key technology indexes, that aiming at the technology supports to the naval ship projects design work in domestic.

Analysis of the flexural mode response of a novel trimaran by segmented model test

A novel ship concept design is significantly an adhoc process. In the preliminary design stage of novel vessels, it is very important to be able to develop an initial estimate of the effects of stiffness and mass distribution on the longitudinal flexural natural frequencies due to different general arrangements in still water at zero speed to satisfy design specifications. For new emerging designs, this estimate has to be made based on a model test. The experiments should also be planned so that scales effects and other features that are not present in full scale case, are minimized. A model with a length of 1.5 meter has been selected. The model was cut into four segments longitudinally and connected by a backbone beam with three elastic hinges joining the four segments. Wet vibration tests were conducted on the model, showed significant influences on the flexural natural frequencies through variations in stiffness and different mass distributions. The whipping frequency was calculated with four degrees of freedom theoretical model to compare with the experimental results. The theoretical model shows a good agreement with the experimental results.

An experimental investigation into the hydrodynamic drag reduction of a flat plate using air-fed cavities

The Air-Cavity Ship (ACS) concept is currently being researched as one of the more promising concepts for economical forms of marine transportation. An Air-Cavity Ship uses an air injection system to isolate the bottom part of the ship's wetted surface from the water and thereby to reduce the frictional resistance. The air cavities are generated injecting air at the keel level of a vessel as such the cavities can extend along considerable portions of the hull bottom thus isolating it from the effect of the fluid. The main objective of an effective air cavity system is therefore to maximize the cavity length whilst minimising the air supply. Building on the lack of published experimental research, this paper presents a recent fundamental experimental investigation on air-cavities underneath a flat plane tested in the Emerson Cavitation Tunnel of Newcastle University. The experimental investigation uses this simplified model to understand the correlation of cavity length and volume with potential drag reduction due to the air cavity. The main objective of the research was to generate both fundamental and practical knowledge that furthered the understanding of the air-cavity phenomenon to help its potential application in practice. In addition an attempt was also made to correlate the findings from this experimental study with air-cavity theory and results from limited previous experimental studies performed in other facilities.

Computation of Free Surface Flows around Box-Shaped Ships by an Unstructured Navier-Stokes Solver

A novel ship concept which is called ultra large block coefficient ship (ULBS) to enable efficient environmentconscious sea transportation is under investigation at Yokohama National University. Since ULBS is supposed to have a very blunt hull, flow field analysis around a ship is crucial for a design of hull forms with better hydrodynamic performance. Computational Fluid Dynamics (CFD) is expected to be an efficient design tool for unconventional hull forms such as ULBS. However, it is desirable to examine applicability of the CFD method before the actual design application. Thus, free-surface flow computations of two box-shaped ships which can be considered as the extreme cases of ULBS are carried out. Grid convergence study is performed with respect to resistance for the verification of the results. Total resistance coefficients are compared with each other and also with available experimental data. The pressure and velocity distributions of the two ships are compared with each other. The flow structures with large separations are observed and the influences of the box geometry to the flow fields are discussed.

Application of Operational Effectiveness Models in Naval Ship concept exploration and design

Traditionally, the Concept and Requirements Exploration process is the first stage of ship design. Concept and Requirements Exploration responds to a stated mission need with early high-level assessment of a broad range of ship design options and technologies. Our design group uses a Multi-Objective Optimization approach to explore the design space and identify non-dominated designs ranked by cost, risk, and effectiveness. Our method of calculating effectiveness in this approach has, in the past, been based on expert opinion. In this study, the use of a more direct physics-based Operational Effectiveness Model approach is considered to provide greater confidence in the validity of effectiveness results and a perception that results are more unbiased and rational. This approach requires significant early investment. How much analysis is enough and is there significant payoff for this significant effort? This paper presents this approach and explores these questions.

ABOŞ KELİMESİNİN KÖKENİ VE ANLAMI

Akraba (kin) has come into our language from the word Ar. Akriba. In Turkish Dictionary, it means one’s who are related with each other with blood relation. Akrabalik (kinship) means one’s who are related with each other viablood or marriage. The concept of kin ship grows and expands viablood, marriage and sometimes with people’s feeling each other closed like a kin. Either viablood or marriage or with people’s feeling each other closed like a kin, kinship, its namings and this whole notion is very common in Turkish society. With the reference of this article, we will analyze the word abo/abbo/abos/abbos which is commonly used in Adiyaman province and its region and we think that it is different with its origin, conceptual scope, social counterpart, social function.

浮力制御方式バラストフリー船の海水交換性能に関する洋上模型実験について

To cope with the problems in the marine ecosystem caused by the ballast water from ships, the International Maritime Organization (IMO) adopted the International Convention for the Control and Management of Ships' Ballast Water and Sediments in 2004. In response to this legislation, ballast water treatment systems are being developed worldwide. The ballast-free ship concept proposed by Yokohama National University is aimed at solving this ballast water problem from a completely different standpoint. In the proposed system, seawater continuously passes through the buoyancy control tank to keep the contents of the water inside the tank the same as that outside the ship. A series of studies on this new concept has been carried out by the authors, including the analysis of seawater circulating performance inside the buoyancy control tanks, an examination of the increase in resistance caused by adding small appendages such as intake and exit gates on the ship bottom, a study of structural integrity of the system, and related work. In the present study, the authors used a scale model of an actual double bottom tank and carried out an experiment to examine the water exchange performance of the proposed system on the open sea. In the model experiment, the water inside the tank was set as fresh water initially, and as time passed, the water inside the tank changed to the seawater outside the tank. The water locality ratio inside the tank was evaluated based on the salinity change of the water inside the tank and the change of the numbers of phytoplankton cells inside the tank. Numerical results and experimental results were compared to examine the performance of the proposed ballast-free system.

FLEXIBILITY VS. SPECIALISATION IN RO-RO SHIPPING IN THE SOUTH BALTIC SEA

The trade-off between flexibility and specialisation implies delicate tasks for transport system designers and marketing managers. The outcome of their efforts ranges from highly specialised solutions for a restricted number of users and types of cargoes to very open systems for common use adapted to accommodate a wide variety of transport demands. The purpose of this article is to adapt theories on openness and trade-offs, characterise a selection of flexible and specialised European short sea shipping concepts and analyse how substantial changes in the future character of the competition with road and rail can affect the development of ro-ro shipping in the South Baltic Sea. A matrix with commercial openness and technological openness on the axes is used for categorising sub-segments in the empirical context of the South Baltic Sea. Foreseeable changes in key cost and competition parameters until 2020 are taken into account in discussing potential scenarios. A plausible outcome for the ferry/ro-ro shipping segment is that a branch with slow services for unaccompanied freight will be diverted from the current homogenous market offerings. During the study, the Swedish Orient Line launched a service with these characteristics, which is analysed in a case study.

Operational options for green ships

Environmental issues and rising fuel prices necessitate better energy-efficiency in all sectors. The shipping industry is one of the major stakeholders, responsible for 3% of global CO2 emissions, 14%–15% of global NO X emissions, and 16% of global SO X emissions. In addition, continuously rising fuel prices are also an incentive to focus on new ways for better energy-effectiveness. The green ship concept requires exploring and implementing technology on ships to increase energy-efficiency and reduce emissions. Ship operation is an important topic with large potential to increase cost-and-energy-effectiveness. This paper provided a comprehensive review of basic concepts, principles, and potential of operational options for green ships. The key challenges pertaining to ship crew i.e. academic qualifications prior to induction, in-service training and motivation were discussed. The author also deliberated on remedies to these challenges.

The Ship, the Plantation, and the Polis:

The Ship, the Plantation, and the <i>Polis</i>:

The Ship, the Plantation, and the Polis:

The Ship, the Plantation, and the <i>Polis</i>:

1A1-R10 外部磁界で駆動する水中マイクロロボットへの母船方式の適用(バイオミメティクス・バイオメカトロニクス(1))

In this paper, a novel individual operation method for magnetically driven underwater microrobots has been presented. This method is based on mother ship concept, in which a cm-sized mother robot can carry a small child agent. To obtain individual operation of the mother ship and the child agent, difference in driving frequency between them was utilized. We could successfully control individual motion and release the child agent from the mother ship by changing the frequency.

Trim and Draft Control Capability of the Variable Buoyancy Ship

The Variable Buoyancy Ship concept has been developed to address the problem of the introduction of nonindigenous aquatic species (NIS) into coastal waters. While this ship design concept essentially eliminates the transport of NIS across the globe, it presents special problems for operators with respect to their control of trim and draft. An investigation was, therefore, undertaken to assess this capability and ensure that adequate capability would be provided. To better visualize this issue, the equilibrium polygon used in early submarine design has been adapted to provide an effective way to characterize the trim and draft control capability of surface vessels. The results of this investigation and resulting design concept modifications are presented.

Recent developments in the design of fast ships

During the last twenty years, Damen Shipyards, a multinational shipbuilding group with 6000 employees worldwide, has done extensive research on the development of hull designs for fast monohull vessels. In the 1990s the Enlarged Ship Concept was developed, leading to highly improved sea keeping capabilities and vessel behaviour in waves at high speed. This hull design concept was applied in the Damen SPa 4207 patrol vessel and has proven extremely successful, reducing vertical accelerations by 50% and, thus, allowing vessels to keep operating at high speed in waves. Over 25 units of the Damen SPa 4207 have been delivered so far. After the successful introduction of the Enlarged Ship Concept, Damen and Delft University continued developing the next generation hull form: the axebow design. Compared to the already good sea keeping capacities of the Enlarged Ship Concept, model tests indicated a further reduction of vertical accelerations. This was proven by real-time measurements on the first built axebow vessels in 2006 and 2007. In the last 3 years, over 30 axe bow supply vessels have been delivered to very satisfied operators. As a next step, Damen has applied the axe bow design to the latest patrol vessel design, the Damen SPa 5009. The first vessel of this design is currently under construction and its trials are scheduled by the end of 2011. The paper describes the background of the research done by Damen and Delft University, focusing on the mathematical and scientific aspects of the axebow design and its application on various ship types. The development and design of the latest Damen patrol vessel, SPa 5009, will be introduced, describing its seakeeping performance, operatability and crew ergonomics. Finally, the paper will mention the current and future research topics that Damen and Delft University are working on together, identifying the developments of the future generation patrol vessels.

Stretching the Future Surface Combatant: Examining the affordability benefits of a twin-variant ship

A ship concept design is presented that utilises a single common hullform across two distinct variants to meet the perceived needs of the Royal Navy's Future Surface Combatant, while satisfying the wide separation in target cost between the variants. This concept emerged from commonalities between the requirements of the Force Anti-Submarine Warfare Combatant (C1) and Stabilisation Combatant (C2) vessels. Both share some requisite capabilities, leading to specific areas where common systems can be adopted. However, other capabilities lead to major differences in the technical solutions that must be employed. While a single base hullform has significant cost advantages, to successfully fulfil both roles while maintaining commonality a number of design innovations are necessary. This paper also estimates the cost savings that could be achieved to adopt the design features proposed. These savings and the flexibility inherent to the design make the vessel well suited to the export market. A final discussion highlights the beneficial role of the twin variant concept in providing part of the affordable future fleet.

ICONE19-43821 NUCLEAR POWERED SHIPS : Findings from A FEASIBILITY STUDY

Nuclear shipping is attractive for several reasons, one of which is its positive effect on emissions (CO_2, NOx and SOx). The benefits, however, do not come without risks of possible harmful effects on humans and wildlife. Nuclear ships set themselves apart from conventional ships, as well as from on-shore nuclear power-plants, on several counts. 1) The reactor-unit are non-stationary, and the reactor is subject to the ship motions. 2) Ship reactors must be compact due to space constraints. 3) Special design considerations are required to ensure reactor safety and security, as well as to enable refuelling. 4) A naval nuclear fuel cycle infrastructure for fuel fabrication, handling, and disposal is needed. Technological feasibility of nuclear shipping is by itself inconclusive to a expansion into civilian applications and use. Civilian nuclear propulsion needs to be commercially viable and politically acceptable. Appropriate legislation must be in place, and nuclear shipping concepts with proven safety records and highest possible nuclear proliferation-resistance must be established. Possible "showstoppers" to a viable nuclear civilian shipping industry are outlined in the paper in view of Political, Technical, Regulatory, Commercial, Safety and Security aspects. Further, different types of ships with different propulsion system are compared in lights of life cycle cost and air emission.

A demonstration of an advanced library based approach to the initial design exploration of different hullform configurations

The importance of requirement elucidation, in shaping both the customers’ needs and initial solutions during the concept stage of the ship design process, has previously been emphasised in the choice of initial design methods. It is well known that alternative hullform styles can bring distinct performance benefits in certain design investigations. However, current design methods or tools suitable for exploring alternate hullform styles during requirement elucidation do not readily facilitate this. This paper describes a library based ship concept design tool and its ability to include exploration of hullform options in the initial exploratory stage of the ship design process. The library based approach utilises sub-structuring to describe the design in terms of four functional subsets to increase the efficiency of the search process. The example presented looks at monohull, catamaran and trimaran hullform options for a fast naval combatant. The paper concludes with the advantages seen in adopting the tool in concert with a configuration-oriented approach to ship design, namely, the UCL Design Building Block approach.