Wyniki wyszukiwania - BazTech

1

Prediction of the main engine power of a new container ship at the preliminary design stage

Cepowski T.

Management Systems in Production Engineering

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2017

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nr 2 (25)

97--99

EN

The paper presents mathematical relationships that allow us to forecast the estimated main engine power of new container ships, based on data concerning vessels built in 2005-2015. The presented approximations allow us to estimate the engine power based on the length between perpendiculars and the number of containers the ship will carry. The approximations were developed using simple linear regression and multivariate linear regression analysis. The presented relations have practical application for estimation of container ship engine power needed in preliminary parametric design of the ship. It follows from the above that the use of multiple linear regression to predict the main engine power of a container ship brings more accurate solutions than simple linear regression.

PL

W publikacji przedstawiono matematyczne zależności pozwalające na prognozowanie szacunkowej mocy napędu nowo budowanych kontenerowców w latach 2005-2015. Przedstawione aproksymacje pozwalają na oszacowanie mocy napędu w oparciu o długość między pionami i liczbę kontenerów. Aproksymacje zostały opracowane przy wykorzystaniu regresji liniowej jednej i wielu zmiennych. Przedstawione zależności mają praktyczne zastosowanie do szacowania mocy napędu kontenerowca dla potrzeb wstępnego parametrycznego projektowania statku. Z badań wynika, że zastosowanie regresji wielu zmiennych daje dokładniejsze rozwiązania niż zastosowanie regresji jednej zmiennej.

2

Approximating the added resistance coefficient for a bulk carrier sailing in head sea conditions based on its geometrical parameters and speed

Cepowski T.

Polish Maritime Research

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2016

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nr 4

8--15

EN

The article presents the mathematical function to calculate the added wave resistance transfer function for bulk carriers. Based on this function, the statistical mean added wave resistance generated by an irregular head wave with arbitrary statistical parameters can be forecasted. The input parameters are: waterplane area, waterplane coefficient, ship speed, and frequency of the regular wave. The model has been developed based on the theory of artificial neural networks. The presented function can be used in design analyses, and for planning shipping routes in situations when basic geometrical parameters of the hull are only available and not the full technical documentation. The article presents sample cases of use of this function to calculate the added wave resistance transfer function and the statistical mean added wave resistance. Another presented application refers to waterplane coefficient optimisation taking into account the added wave resistance at the stage of preliminary bulk carrier design.

3

The modeling of seakeeping qualities of Floating Production, Storage and Offloading (FPSO) sea-going ships in preliminary design stage

Cepowski T.

Polish Maritime Research

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2010

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nr 4

3-12

EN

This paper presents an analysis of a presently applied approach to accounting for seakeeping qualities of FPSO sea-going ships and possible using it in preliminary design stage. Approximations of heaving, pitching, green water ingress on the deck and slamming of FPSO ships, based on main ship design and wave parameters, are presented. The approximations were elaborated with the use of the linear regression method and theory of artificial neural networks for a very wide range of FPSO ship dimensions and hull forms. In the investigations ship operational conditions were limited to those occurring in real service of FPSO ships, described by means of the so called operational scenario. Such approach made it possible to reach simultaneously high approximation accuracy and simple structure of mathematical model.

4

Influence analysis of changes of design parameters of passenger-car ferries on their selected sea-keeping qualities

Cepowski T.

Polish Maritime Research

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2010

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nr 1

25-32

EN

The main scientific aim of this research was to elaborate design guidelines which could make it possible to improve sea-keeping qualities of passenger-car ferries. The searchedfor design guidelines were prepared in the form of regression functions as well as artificial neural networks on the basis of the results obtained from calculations with the use of numerical methods based on the theory of planar flow around a body. The guidelines make it possible to predict ship roll, sea-sickness index, lateral and vertical accelerations on the basis of quantities available in the preliminary stage of ship design.

5

Estimation of main engine power of seagoing ship at preliminary design stage

Charchalis A., Krefft J.

Journal of KONES

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2010

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Vol. 17, No. 4

89-95

EN

Permanent growth of the container shipbuilding has led to the need of research - developing activities with references to design and ship building process. The requirements for the container vessels have been modified and changed compared with the ships built in the eighties of the past century. The ships capacity have been increased up to and even above 10 000 twenty feet containers (TEU) with the service speed above 25 knots. For such a giant sea going vessels with the overall length above 300 meters and draught above 10 meters the ship hull resistance characteristics have been modified. Those conditions bring to the situation where the propulsion power for the seagoing ships reached 80 MW. The estimation of the main engine power relation in the preliminary design stage is the main aim of the paper. The problem is such important as in that stage the most important design decisions with relatively low investment costs are determined. Moreover, the preliminary design stage distinguishes that the designer possesses just a few design parameters given by the ship owner of the future vessel. That is why the correct choice of the main engine power is difficult to determine. Determination of the main propulsion power impacts the electric and heat energy amount and the production way of both energy forms. The main engine equation has been determined based on the container ship's parameters for the entire range of container vessels load capacity (TEU). The values of the design parameters have came from author 's data base for the contemporary container vessels.