Figure 4 - uploaded by Frans van Walree
Content may be subject to copyright.
Source publication
For a group of interested parties, i.e. the Royal Netherlands Navy, Damen Shipyards at Gorinchem (NL), the Royal Schelde Group at Vlissingen (NL) and the United States Coast Guard from Baltimore (USA) the Shiphydromechanics Department of the Delft University of Technology and MARIN at Wageningen carried out an extensive research program on three co...
Context in source publication
Citations
... 5). Глісер, побудований за цим проєктом, показав суттєве підвищення мореплавності за швидкості 35 вузлів, але на гладкій воді він поступається ходкістю суднам з іншими обводами корпусів [4]. ...
У доповіді проаналізовано сучасне ставлення до проблем гідродинаміки швидкохідних суден та методи їх вирішення з комплексним застосуванням динамічних принципів підтримки та багатокорпусності суден. Наведено результати досліджень, на яких зосереджує свої наукові пошуки Інститут гідромеханіки НАН України і які є базою для вирішення фундаментальних та прикладних проблем гідродинамічного опору суден за великих чисел Фруда і Рейнольдса на основі подальшого розвитку теорії і методів експериментального дослідження та створення ефективних методів розрахунку гідроаеродинамічних характеристик швидкісних суден в умовах реального хвильового впливу.
... It was found that although a large safety margin is used in the DNV rules, design pressures were easily exceeded during tests. Keuning et al. (2006) published the results of an extensive research program on three 55 meter long monohull Patrol Boat concepts. The aim of the study was to gain insight in the aspects that most impact the craft operability at sea and try to evaluate their limit values of motions and accelerations to ensure safe operation of the ship. ...
Full scale seakeeping trials experiments are very limited, in particular for the case of leisure planing hulls. In this study, an in-depth analysis of both head and following sea trials of a 65 ft planing hull yacht in mild weather conditions is presented. The analysis deals with both propulsion and motion measurements, with particular attention on the relationships between them. Full and model scale experiments in calm water have been carried out in order to provide a baseline for seakeeping data.
Both propulsion and motion datasets have been analyzed in frequency and time domain in order to provide the most comprehensive assessment of the relationships between torque response and hull motions. In the frequency domain, torque RAOs have been defined and discussed, where in the time domain, an in-depth analysis of torque response phase has been carried out.
The main novelty of the present study lays in the detailed analysis of both head and following sea motion and propulsion data of a pleasure planing hull yacht, in particular the assessment of the propulsion system response phase. In addition, an ad-hoc experimental setup to measure the full-scale propeller shaft mechanical properties has been described and results are compared with initial guessing.
... These articles relate to studies of the performance of the axe-bow and the other monohull types that are used for Keuning and Van Walree, [6], have carried out a comparative study of the hydrodynamic behavior of three fast patrol boats using special hull forms. Three types of hull form are used, namely the enlarged ship type (ESC), the axe bow type and the wave-piercing type. ...
As a sovereign maritime country, Indonesia has an obligation to protect, maintain, and manage marine and fishery resources. Patrol boats as the primary means of monitoring marine and fishery resources are needed in response to several problems and threats that may occur, such as illegal fishing, destructive fishing, violations of zoning in fisheries conservation areas and others. Apart from having to be adequate on the number of units, the patrol boats must also have suitable technology to support pursuit operations and suppress violations. The main objective of this research is to investigate the total resistance and intact stability behavior of the developed axe bow hull geometry for the patrol boat hull. The preliminary design is started with the determination of the principal dimension of the patrol boat. Then the hull geometry configurations were made with the variation of the depth of bow and the water line spline type. In the case of the depth of bow, the bow with the additional depth of 30%, 40% and 50% of the draft was investigated. Otherwise, the water line spline type was configured as convex spline, concave spline and straight spline. According to the numerical analysis, the axe bow hull with the depth of bow of 30% and the straight spline type was presented the smallest total resistance performance. However, in the case of intact stability performance, all developed axe bow hull presented a similar righting moment lever arm (GZ curve). It is indicated that the total resistance of the axe bow hull is influenced by the depth of bow and water line spline type. Furthermore, those variables have a slight influence on intact stability performance.
... While hydrodynamic analysis predicting forces, movement and structural load as the result of the ship movement on the water, the water flow around the ship including the effect of the sea wave. Though the hydrodynamic analysis is complex but simplicity and prediction of the fluid flow as well as the ship geometry can be applied [2,4,7]. ...
The boat plays significant role in supporting the household business scale for the seaweed farmers. Their current boat are made from fiberglass reinforced plastic (FRP) which is lighter then the wooden boat. However, based on the field survey in the seaweed farmers boats in the area of Pattontongan village, Jeneponto regency, their boat is susceptible for sinking if any leak is occur on the boat body since they are not designed with the reserved buoyancy system. Geometry and the reserved buoyancy of their boat become the serious issues. Hence, an improved design for their boat is need to be developed with the criteria of the boat capacity and safety. This paper discusses two of the improved design of the boats which are ND 1 (design 1) and ND 2 (design 2). The result shows an improved design with the additional of the boat reserved buoyancy while considering the boat capacity. The parameter of the boat design is the relationship between the boat reserved buoyancy volume and the boat weight which is called anti sinking ratio. The anti sinking ratio for ND1 with the boat length 6 meters, width 0.85 meter, and height 0.5 meter is ≥ 1. The ratio is obtained in the condition of the boat reserved buoyancy of 0.066m ³ and the boat carrying capacity of 0.969m ³ . Meanwhile, the anti sinking ratio for ND2 with the boat length of 4.2 meters, width 1 meter and height 0.5 meter is ≥ 1 in the condition of the boat reserved buoyancy of 0.055m ³ and the boat carrying capacity of 0.936m ³ .
... Keuning et al. (2002) proposed a further extension of the above-mentioned concept, known as the Axe Bow Concept (ABC). From relevant tests, Keuning et al. (2011) and Keuning and Van Walree (2006) reported considerable reductions of vertical acceleration peak values in comparison to the ESC design. Grigoropoulos et al. (2010) and Grigoropoulos and Damala (2011) presented seakeeping results in regular and irregular waves for a systematic series of five double-chine wide-transom hull forms, with warped planing surfaces and length to breadth ratio ranging Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/oceaneng ...
The paper focuses on the analysis of experimental seakeeping data in irregular head sea relative to constant deadrise and warped model representative of current design trends for planing hull forms. Tests have been performed at four volumetric Froude numbers ranging from 2 to 4 in one sea state. Due to non-linear nature of high-speed craft dynamics, measured motions and accelerations have been statistically analysed with the aim to find the best-fit distributions. Obtained results for heave and pitch confirm that Rayleigh and Cartwright distributions can be applied with good confidence for statistical analysis of heights and maxima/minima respectively. Weibull distribution was found to be the best-fit for statistical analysis of vertical acceleration maxima at CG and bow. Finally, the mean of 1/3rd highest vertical accelerations for both models have been compared with Fridsma's data showing the covered range of velocities and sea states. The procedure for model-ship correlation is shown to make the results available in design practices.
... These modifications were aimed at reducing the wave exciting forces and the hydrodynamic lift in particular in the forward end of the ship whilst maintaining adequate buoyancy. Keuning and Van Walree (2006) and Keuning et al. (2011) from the tests carried out reported a considerable improvement in vertical accelerations peaks at the bow with this concept when compared with the ESC. ...
One monohedral and three warped hard chine planing hull forms were designed at Department of Industrial Engineering, University of Naples. All models have the same transversal section at 0.25 L from the stern with 16.7° deadrise angle. Warped models have deadrise angle linearly varying along the hull length. In previous work the results of an extensive experimental program in calm water were presented. This paper is focused on the seakeeping assessment in regular waves.
Aim of this research is the evaluation of the effect of deadrise angle variation along the hull length on seakeeping characteristics. Regular wave tests have been chosen to get better insight on motion and acceleration properties connected with warped hull forms and to provide a benchmark for CFD of planing hulls.
Models with same load coefficient CΔ=0.428 were tested at three volumetric Froude numbers FrV=1.92, 2.60 and 3.25. Reported results are nondimensional responses for heave, pitch, and accelerations at 0.5L and bow. Particular emphasis was given to acceleration analysis by crest to trough method and spectral analysis of first and second harmonics. All results are commented with respect to hull form variation. Uncertainty analysis has been performed according to ITTC 2011 recommendations.
... Keuning et al. (2002) proposed a further extension of the above-mentioned concept, known as the Axe Bow Concept (ABC). From relevant tests, Keuning et al. (2011) and Keuning and Van Walree (2006) reported considerable reductions of vertical acceleration peak values in comparison to the ESC design. Grigoropoulos et al. (2010) and Grigoropoulos and Damala (2011) presented seakeeping results in regular and irregular waves for a systematic series of five double-chine wide-transom hull forms, with warped planing surfaces and length to breadth ratio ranging Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/oceaneng ...
The paper presents the results of planing hull seakeeping tests in irregular seas. The tested model belongs to a small systematic series developed at the University of Naples; it is a prismatic hull very similar to the well-known Fridsma's models. The 16.7 degrees deadrise angle, length-to-breadth and load coefficient are representative of modern hull forms of pleasure boats. Tests in irregular waves have been performed at three speeds for one displacement in three sea states. The measured heave, pitch, acceleration at the centre of gravity and at bow have been analysed in the time domain and the results are presented in terms of significant values (the mean of 1/3rd highest values). They are given in tabular and graphical form. Furthermore, the obtained results are commented with respect to the state of the art in planing hull seakeeping, and compared with the available experimental data from literature. The conclusions highlight the applicability of these data in design practice, commenting on trends and the range of significant parameters.
... Full scale trails have indicated that particularly the larger vertical peak accelerations pose the most important limiting criterion from a human perspective [3]. In addition, the maximum peak accelerations also increase the damage potential to on board equipment or, in some cases, may even compromise the structural integrity of the ship [4]. ...
... The hull form that is considered to demonstrate the control system performance was designed in 2006 by Keuning and Van Walree [3]. Here it was used as a benchmark vessel and the hull was developed according to the philosophy which is commonly referred to as the "Enlarged Ship Concept" (ESC). ...
... The large quantity of experimental data on the ESC makes it particularly suited for a current research application, since it enables a thorough validation of the simulation model. The original (full scale) waterline length of the ESC is 55 meters [3]. However, for the current research application a smaller length was preferred, whereas thrust control would be more effective on smaller sized high speed vessels due to their relatively high power to weight ratio and because these vessels generally operate at higher Froude numbers. ...
This article presents a proactive ride control system that is specifically designed to reduce the extremes in the vertical acceleration signal of a fast ship in waves. The ride control system uses an anticipatory control strategy to be able to intervene prior to the actual wave impact. The feasibility and performance of this proactive approach has been investigated using a ship motion simulation program. During the simulation continuous real-time ship response predictions are made based on the incident wave to estimate the acceleration level. The control system intervenes when the predicted vertical accelerations exceed a certain threshold value by adjusting the forward speed and the pitch motion of the vessel. The computational results demonstrate a significant improvement in the operability by using this proactive ride control system. The vessel can maintain a high average forward speed, while most peak accelerations can be limited to the specified threshold value.
Bulbous bows have been applied on a large variety of low-speed blunt ships to reduce wave-breaking resistance. However, the impact of bulbous bow shapes on maneuverability remains unsolved. Three scaled model hulls designed by Hiroshima University, which are modified from standard KVLCC2 tanker with different bulbous bows, from protruding bow to vertical stem, are studied. Forces and moments of the bare hulls at drifting conditions are obtained from Computational Fluid Dynamics (CFD) simulations. Service speed = 0.166, and the double body method and free surface method are utilized to compare the free surface effects on the resistance characteristics. Pressure distribution, vorticity, and surface flow features, meeting of turning test criteria of advance and transfer are discussed to demonstrate the hydrodynamic performance and turning ability of the three ships. Simulation results show good consistency with experimental results, and it is concluded that the vertical stem helps achieve a resistance reduction, and performs better in turning operations. However, for accurate mathematical models, further studies need to be carried out for eliminating the yaw moment and coupled hydrodynamic interaction among ships and appendages in the present work.
