Wyniki wyszukiwania - BazTech

1

Optimization of space under main deck on landing craft utility (LCU) ships to increase loading capacity

Sugeng S., Ridwan M., Sulaiman S., Khristyson S. F.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

|

2022

|

Vol. 16 No. 1

99--103

EN

With this optimization, the cargo will increase and the ship's revenue will also be more. The LCU ship that we know so far is a ship whose cargo is always above the main and the space under the main is unused Void Space. The purpose of this study is to determine the optimization value of the use of space under the main deck of the Landing Craft Utility (LCU) ships. method used in this study is a comparison with several previous ship approaches to produce evaluation results from the addition of loading space under the main deck and calculation of stability using computational software approximation. LCU design of under main deck space with a maximum vehicle value can accept a vertical moment of 2750 mm. With a structural strength of 13150 tons. A series of numerical experiments show that the proposed method can effectively produce a satisfactory LCU ship design optimization plan for ship owners.

2

Wpływ zatopienia pomieszczeń pokładu łodziowego na stateczność początkową okrętu szkolnego

Mironiuk W., Łosiewicz Z.

TTS Technika Transportu Szynowego

|

2015

|

R. 22, nr 12

1084--1088, CD

PL

W referacie przedstawiono zagadnienia obliczeniowe stateczności okrętu szkolnego z zatopionymi przedziałami okrętowymi na pokładzie łodziowym. Określono algorytm obliczeń wysokości metacentrycznej z uwzględnieniem powierzchni swobodnej po zatopieniu wysoko położonych przedziałów okrętu szkolnego. Na podstawie wyników obliczeń przedstawionych w postaci tabelarycznej i graficznej sformułowano odpowiednie wnioski.

EN

The paper presents the computational stability is-sues with high flooded ship compartments on the boat deck. Defined metacentric height calculation algorithm taking into account with the free surface effect after flooding high located ship compartments. Based on the results of the calculations presented in tabular and graphical form suitable conclusions were done.

3

Variations of Ship’s Deck Elevation Due to Stochastic Process of Containers Loading

Krata P.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

|

2015

|

Vol. 9, no. 4

467--473

EN

The stochastic process of container loading is described in the paper with special emphasis to ship motion when she is lying at a quay. The 3 DOF system was applied to describe rolling, pitching and heaving of a vessel which may cause a significant variations of momentary deck elevation. The realistic range of such variations are assessed for a variety of cargo locations on-board and a phase shift between two independent gantries engaged in cargo operations. The process is modeled with regard to random character of crucial variables affecting ship motion due to cargo loading.

4

System wspomagania decyzji kapitana w trudnych warunkach pogodowych

Sacharko A

Zeszyty Naukowe Akademii Morskiej w Gdyni

|

2013

|

nr 82

62--69

PL

W artykule opisano systemy wspomagania decyzji kapitana statku w czasie eksploatacji, zwłaszcza decyzji dotyczących bezpiecznego operowania statkiem w trudnych warunkach pogodowych. Falowanie podczas trudnych warunków pogodowych jest jednym z czynników, które najbardziej obniżają wydajność eksploatacyjną statku, dlatego niezbędną składową eksploatacji statku jest proces decyzyjny, który wiąże się między innymi z warunkami pogodowymi, w jakich pływa statek.

EN

The paper describes an onboard decision support system to support ship operation, in particular on decisions about ship handling in waves, which will contribute to vessel safety. The effect of waves in rough weather is one of the factors that most degrade a ship’s operational efficiency. Therefore, the tactical judgment involved in the ship handling decision process takes an essential part in navigation.

5

3D CDF modeling of ship's heeling moment due to liquid sloshing in tanks - a case study

Krata P., Jachowski J.

Journal of KONES

|

2010

|

Vol. 17, No. 4

245-251

EN

Modeling of liquid sloshing inside partly filled ships' tanks can be carried out by a variety of methods. The simplest and perhaps the less reliable is a quasi-static approach which is, however, recommended in the Intact Stability Code by the International Maritime Organization. Hence the only advantage of the static estimation of liquid sloshing is simplicity of calculations, the research into the application of CFD (Computational Fluid Dynamics) was performed in Department of Ship Operation at Gdynia Maritime University. The paper presents results of numerical simulations o f a liquid sloshing phenomenon performed by means of a code Fluent. The research was focused on a computation of the heeling moment affecting stability of a vessel, especially on the dynamic effects, which are omitted in obligatory intact ship's stability regulations nowadays. The computed distributions of dynamic pressures on tank walls were carried out for large oscillation amplitude which is characteristic for stormy sea conditions. Ali the simulations were computed in 3D mode and they provide high accuracy results. A case study described in the paper enables realistic comparison of the results of CFD liquid sloshing simulations and the simple statics based computations. The study reveals some weaknesses of the contemporary quasi-static approach towards the free surface effect and it might be the contribution to the more sophisticated estimation of the ship's stability than it is achieved nowadays.

6

Linear characteristics of the sloshing phenomenon for the purpose of on-board ship’s stability assessment

Krata P.

Journal of Theoretical and Applied Mechanics

|

2009

|

Vol. 47 nr 2

307-320

EN

The paper presents results of experimental research and numerical simulations of the sloshing phenomenon. The research was focused on computation of the heeling moment affecting stability of a vessel. The proposed linearisation enables application of the results to the asses- sment of the ship’s stability. The dependence of the heeling moment upon localisation of a tank in the ship’s hull is analysed. The heeling moment obtained in the course of the research was compared to the moment computed in accordance with the Intact Stability Code requirements. The study may be a contribution to the more sophisticated estimation of the ship’s stability than it is achieved nowadays.

PL

Artykuł prezentuje wyniki badań eksperymentalnych i symulacji numerycznych ruchu cieczy w niepełnych zbiornikach statku. Istostą badań było wyznaczenie momentu przechylającego statek wskutek ruchu cieczy w zbiornikach, co wpływa na stateczność poprzeczną statku. Zaproponowana metoda linearyzacji momentu umożliwia implementację wyników badań przedmiotowego zjawiska do praktyki oceny stateczności poprzecznej statku. Szczególną uwagę zwrócono na zależność pomiędzy momentem przechylającym statek a lokalizacją niepełnego zbiornika względem osi kołysań bocznych. Zarazem wyznaczany moment przechylający został porównany do quasi-statycznego momentu wyliczonego zgodnie z zaleceniami Kodeksu ISC. Przeprowadzone badania mogą stanowić element poprawy wiarygodności oceny stateczności statku dokonywanej ru- tynowo przez oficerów ładunkowych.

7

Ship's heeling moment due to liquid sloshing in tanks - 3D attitude

Jachowski J., Krata P.

Journal of KONES

|

2009

|

Vol. 16, No. 2

191-197

EN

The matter of the paper refers to the dynamic stability of a vessel as an important factor affecting her safety at seaway. Ship 's seakeeping behaviour, which comprises the notion of her stability, is one of the researched key issues leading to the increase in understanding of the safety qualifying factors. Liquid sloshing phenomenon is a result of partly filled tank motions. As a tank moves, it supplies the energy to induce and sustain the fluid motion. The dynamic behaviour of a vessel at seaway is considerably affected by the dynamics of free liquid surfaces, therefore the influence of fluid movement taking place in partly filled tanks on the safety of ship 's exploitation process is emphasized. The paper presents the results of the experimental research and the numerical simulation of the sloshing phenomenon. The research was focused on the computation of the heeling moment affecting the stability of a vessel, especially dynamic effects, which are omitted in obligatory intact ship 's stability regulations nowadays. The experiment performed in the course of the research was carried out in Department of Ship Operation at Gdynia Maritime University. The unique test apparatus was designed and built. It enables to measure dynamic pressures on model tank walls for large oscillation amplitudes, which are characteristic for stormy sea conditions. The numerical simulations of liquid sloshing phenomenon, took into account the viscosity of liquid and the turbulence of considered flows. All the simulations were computed in 3D mode and they provide high accuracy results. The spatial distribution of dynamic pressures on model tank walls enables computation of heeling moment due to liquid sloshing which affects ship 's stability. Further analysis of obtained moments was carried out. The study may be the contribution to the more sophisticated estimation of the ship's stability than it is achieved nowadays.

8

Stability and safety of ships : holistic and risk approach

Kobyliński L.

Journal of Polish Safety and Reliability Association

|

2007

|

Vol. 2

211--218

EN

Present stability regulations developed over the years by IMO reached definite conclusion with the adoption of the Revised Draft of the Intact Stability Code. The criteria included there are design criteria of the prescriptive nature, based mainly on statistics of stability casualties. Currently IMO is considering development of criteria based on ship performance. Concept of such criteria is, however, at present not agreed. The criteria are working comparatively well with regard to the majority of conventional ships, however advent of very large and sophisticated ships of non-conventional features caused that those criteria may be inadequate. The author advances the idea consisting of application of safety assessment and risk analysis using holistic and system approach to stability. Safety against capsizing (or LOSA accident) is a complex system where design, operational, environmental and human factors have to be taken into account. Although this seems to be a very complex task, in the opinion of the author it may be manageable and could be applied for safety assessment of highly sophisticated and costly ships.