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1
Content available remote Rewizja przybliżonej metody szacowania oporu całkowitego kadłuba płynącego w przechyle
Karczewski Artur, Malinowska Katarzyna, Pruszko Hanna
Mechanik
|
2019
|
R. 92, nr 1
42--45
PL
Na tle innych obiektów pływających jacht żaglowy wyróżnia się m.in. tym, że choć jest zaprojektowany jako pojazd poruszający się w pozycji wyprostowanej, to jednak znaczną część czasu żegluje w przechyle. Dlatego tak ważne jest poznanie zachodzących wtedy zjawisk, zwłaszcza związanych z oporem hydrodynamicznym. W artykule zaprezentowano porównanie oparte na weryfikacji wybranej, przybliżonej metody oszacowania zmian oporu całkowitego gołego kadłuba w wyniku jego przechylania się, polegającej na sprawdzeniu wykonanym metodą numeryczną (CFD) i eksperymentalną (przez badania modelowe). Obliczenia uproszczone oparto na metodach opracowanych w ramach serii Delft (The Delft Systematic Yacht Hull Series, DSYHS). W artykule przedstawiono wyniki oszacowań dla wybranego jachtu żaglowego.
EN
Unlike other floating structures yachts sail in heel most of their life, however, resistance in design process is estimated in upright condition. Thus, it is crucial to investigate into phenomena related to change of hull resistance due to heel. This article presents assessment of influence of yacht’s heel on bare hull resistance using approximate method. Results were compared to towing tank experiments and numerical computation (CFD). Calculations were performed using formulae developed based on The Delft Systematic Yacht Hull Series. Article presents results of analysis for specific sailing yacht.
2
Content available Estimation of the vessel's sailing resistance in the preliminary analyses
Charchalis Adam
Journal of KONES
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2019
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Vol. 26, No. 1
17--22
EN
In this article is presented the methodology of calculation of principal parameters of hull a vessel and resistance components. The approximate method is based on the analysis of the results of model tests and surrender tests presented in the literature. Ship owners' preliminary assumptions for new ship consist of deadweight, speed-shipping line and others. This goal needs definition of principal dimensions of a vessel, which are the basis for further calculations of hull’s resistance and evaluation of necessary power of main engine to fulfil shipping requirements. The route and its environment, type of cargo, quantity to be moved, and value of the cargo and port facilities are typical features, which will be considered when evolving the size, speed, and specification of a suitable ship. Specific service requirements will be similarly considered when evolving vessels such as warships, passenger ships or fishing vessels. Selection of main dimensions of vessel is limited by related to seaways or harbours characteristic and limitations rules regarding buoyancy, stability, hull strength, manoeuvring capability, etc. The influence of the main dimensions of the ship and their coefficients of maritime and strength properties of the ship were presented. Moreover, formulas for calculation of the ship's resistance components, such as friction resistance, and wave shape, as well as the results of calculations for different types of ships, for the assumed deadweight and speed of sailing, are presented.
3
Content available Hydrodynamic multidisciplinary optimization of a container ship and its propeller using comprehensive HPSOP code
Zakerdoost H., Ghassemi H.
Zeszyty Naukowe Akademii Morskiej w Szczecinie
|
2018
|
nr 53 (125)
48--56
EN
Hydrodynamic shape optimization plays an increasingly important role in the shipping industry. To optimize ship hull and propeller shapes for minimum total (friction+wave) calm-water resistance and maximum open water efficiency, respectively, the main particulars of a hull and propeller model are considered as design variables. The optimization problem is performed by using an integrated hull-propeller system optimization problem (HPSOP) code in a multi-level and multi-point methodology in early-stage ship design. Three numerical methods with variable fidelity are employed to carry out the hydrodynamic performance analysis of a ship’s hull and propeller. A ship and its propeller are selected as initial models to illustrate the effectiveness of the proposed optimization procedure. The numerical results show that the developed technique is efficient and robust for hydrodynamic design problems.
4
Content available Rewizja przybliżonych metod obliczania oporu całkowitego kadłuba z wykorzystaniem badań modelowych wybranego jachtu żaglowego
Malinowska A., Karczewski A., Pruszko H.
Prace Wydziału Nawigacyjnego Akademii Morskiej w Gdyni
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2018
|
Z. 33
42--52
PL
Rewizja opiera się na weryfikacji wybranych przybliżonych metod prognozowania oporu całkowitego gołego kadłuba, opracowanych w wyniku badań systematycznej serii kadłubów jachtów żaglowych w latach 1973–2010, znanych jako The Delft Systematic Yacht Hull Series (DSYHS). Zademonstrowano wyniki otrzymane z wykorzystaniem wzorów przybliżonych (Metoda Delft), obliczeń numerycznych (CFD) i badań modelowych dla wybranego jachtu żaglowego o nowoczesnym kształcie kadłuba wraz z ich dyskusją.
EN
The revision is based on the verification of approximate methods of the prediction of the total resistance of the bare hull developed in the results of a systematic study of a series sailboat hulls from 1973 to 2010 known as The Delft Systematic Yacht Hull Series (DSYHS). Demonstrations were obtained based on approximate formulas (Delft method), numerical calculations (CFD) and the towing tank test for a selected sailing yacht with a modern hull shape along with a discussion of results.
5
Content available Energy saving procedures for fishing vessels by means of numerical optimization of hull resistance
Abramowski T., Sugalski K.
Zeszyty Naukowe Akademii Morskiej w Szczecinie
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2017
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nr 49 (121)
19--27
EN
This paper presents the general method for hull shape optimization of fishing boats with the objective of reducing resistance. In particular, it presents an example of the results of the application of resistance-reducing devices such as the ducktail, the cylindrical bulb and the streamlined bulbous bow. The resistance was determined using computational fluid dynamics (CFD). For the purpose of flow simulation, the OpenFoam system, distributed under an open source license, was used. The turbulent, unsteady flow with free surface liquid around the analyzed hulls was computed and investigated for potential resistance reduction. Ultimately, the calculation results were generalized by the parameterization of dimensionless geometric variables for the shape of a bulbous bow and were given in a form suitable for practical application in the hull design process.
6
Content available Estimation of hull’s resistance at preliminary phase of designing
Charchalis A.
Journal of KONES
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2017
|
Vol. 24, No. 1
77--82
EN
In this paper are presented the methodology of calculation of hull resistance components, principal parameters of a vessel, necessary for calculation of displacement in relation to vessel’s type. That methodology concerns analysis of designing ways at early stage of ship’s power calculation. Ship owners' preliminary assumptions for new ship consist of deadweight (for container vessel load capacity TEU), speed shipping line and others. Taking it as a base, in early stage of design one has to select propulsion type. This goal needs definition of principal dimensions of a vessel, which are the base for further calculations of hull’s resistance and evaluation of necessary power of main engine (engines) to fulfil shipping requirements. In the paper, are presented major constraints for designing of new vessels coming from ship-owner assumptions such as seafaring limitations and safety of shipping regulations due to Classification Societies Rules or coming out from designing experience. In the paper are presented components of ship’s resistance and methods of total resistance calculations what is a basis for power calculation and propulsion designing. Moreover, are presented results of calculations of resistance components of different types of ships, and variety of displacement and sailing velocity. It has to be assumed, that presented method concerns preliminary design stage and can vary from different ships classes and constructions of hulls.
7
Content available remote Badania wpływu kształtu kadłuba na właściwości eksploatacyjne pasażerskiego statku śródlądowego. Opór jednostki dwukadłubowej
Abramowicz-Gerigk T., Burciu Z., Jachowski J.
Zeszyty Naukowe Akademii Morskiej w Gdyni
|
2016
|
nr 97
16--24
PL
W artykule przedstawiono badania wpływu kształtu dwukadłubowej pasażerskiej jednostki śródlądowej na opór hydrodynamiczny oraz analizę możliwości redukcji jej zanurzenia poprzez modyfikację kształtu kadłubów bez zmiany objętości podwodzia, długości i szerokości jednostki. Uwzględniono zmianę szerokości kadłubów, asymetrię wewnętrzną i modyfikację kształtu dna w części rufowej. Na podstawie wyników symulacji numerycznych obliczono i porównano opory dla przyjętych kształtów przy założonej prędkości projektowej.
EN
The paper presents the investigations of the influence of a passenger inland vessel hull form modifications on hydrodynamic resistance along with the analysis of possible ship draught reduction due to the hull form modification without change of ship displacement, ship length and breadth on waterline. The increase of both hull breadths, design of non-symmetric internal shapes of the hulls and modification of the bottom slope in the aft part of the hull were tested. On the basis of numerical simulation the ship resistance at the design speed was calculated and compared for each of the four tested hull forms.
8
Content available remote Technologiczne i eksploatacyjne metody zmniejszania oporów kadłuba w celu obniżenia zużycia energii na statkach morskich
Jurdziński M.
Zeszyty Naukowe Akademii Morskiej w Gdyni
|
2013
|
nr 82
23--37
PL
W pracy przedstawiono uwagi dotyczące budowy kadłuba w aspekcie zmniejszenia oporów w ruchu. Omówiono teoretyczne podstawy wpływu oporów kadłuba na straty prędkości i zwiększenie zużycia paliwa. W dalszej części opisano wpływ chropowatości kadłuba na spadek prędkości oraz metody konserwacji jego podwodnej części.
XX
The paper deals with methods of ship hull construction due to reduce the fuel consumption. The principle of the ship resistance in fouling on speed reduction, power increase and emission of GHG has been discussed. Additionally the ship speed reduction due to hull fouling and its antifouling protection has been shown.
9
Content available Wpływ warunków nawigacyjnych na parametry pracy układu napędowego statku śródlądowego
Skupień E., Restel F. J.
TTS Technika Transportu Szynowego
|
2013
|
R. 20, nr 10
3513--3520
PL
Parametry pracy układu napędowego statku, zależą od wytwarzanego przezeń naporu i koniecznego do pokonania oporu wytwarzanego przez jednostkę. Opór jaki stawia woda zależy od warunków nawigacyjnych panujących na drodze wodnej. W referacie przedstawiono wpływ warunków nawigacyjnych na pracę układu napędowego statku śródlądowego. Wskazano metody określania parametrów pracy układu napędowego, metody wyznaczania oporu oraz współczynników oddziaływania. Referat ma charakter poglądowy.
EN
The parameters of the propulsion system depends on the generated pressure and the resistance necessary to overcome produced by the unit. The water resistance depends on the navigation conditions on the waterway. The paper presents the influence of navigation conditions on the work conditions of the propulsion system of ship. The methods for determining the parameters of the drive system, the method of determination of resistance and impact factors were mentioned.
10
Content available Experimental investigation of deflector's angle influence on energy absorption
Gieleta R., Barnat W., Niezgoda T.
Journal of KONES
|
2012
|
Vol. 19, No. 4
201-205
EN
Numerical simulations without preliminary validation and model verification are vulnerable to errors. Best results are obtained when full experimental research is provided. Such tests are expensive and may be dangerous. Due to cost control and personnel safety, studies are often done in scale. Scale can affect both construction dimensions and applied load. In this paper four different vehicle's bottoms are examined: flat bottom and 3 types of deflectors. The paper presents four different vehicle's bottom shapes in order to examine deflector angle influence on energy absorption. The test included 4 cases: flat bottom broken-shaped deflector and deflectors with different apex angles 124 centigrade and 144 centigrade. For all cases the distance between explosive and panel was approximately 400 mm. The charge used was 100 g TNT. Flat bottom and deflectors were made of St3 steel with 2 mm thickness. For the purpose of the research a special test stand to examine effects of detonation wave was used. The force measurement system was designed in Department of Mechanics and Applied Computer Science. As a result, force versus time plots were obtained. The use of any deflector decreases maximum force affecting vehicle's hull.
11
Content available Analysis of hull resistance of pushed barges in shallow water
Tabaczek T., Kulczyk J., Zawiślak M.
Polish Maritime Research
|
2007
|
nr 1
10-15
EN
These authors performed a set of numerical calculations of water flow around pushed barges differing to each other by bow forms. The calculations were executed by means of FLUENT computer software. Turbulent free-surface flow of viscous liquid was considered. In this paper the calculated values of barge hull resistance split into bow, cylindrical and stern part components, have been compared and presented.
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