scholarly journals Numerical Investigation on Flood Water Sloshing Influence on Intact and Damaged Stability of Ship

2022 ◽  
Vol 16 ◽  
pp. 261-273
Author(s):  
Poonam Mohan ◽  
A. P. Shashikala
Keyword(s):  
Ship Motion ◽  
Water Dynamics ◽  
Large Space ◽  
Flood Water ◽  
Motion Response ◽  
Damage Location ◽  
Damage Stability ◽  
Metacentric Height ◽  
Damaged Stability ◽  
Volume Of Fluids

Sloshing affects the intact and damage stability of the ship, which causes variation in dynamic metacentric height (GM) under critical load conditions. The transient flooding soon after the ship damage is analyzed, with floodwater accumulation in large space and causing the ship to suffer huge heel angles. The ship motion and stability changes when sloshing becomes high in partially flooded compartments. Most of the previous researches focus on the motion response of ship alone, hence the variation of stability due to sloshing is to be more critically studied. In the present study, three critical damage locations are identified and flooding through these locations are analyzed using the volume of fluids method. The method focus on finding damage ship motion response, flood water dynamics, and coupled dynamics of both. This is studied using the numerical method FLOW3D. Motion and stability behaviour will be different for different damage locations; hence portside, starboard-side, and aft-end bottom damage cases are considered. The effect of compartment shape and damage location on motion response and stability of the damaged ship is highlighted.

scholarly journals Assessment of Survivability of Surface Combatants after Damage in the Sea Environment

2017 ◽  
Vol 33 (02) ◽  
pp. 156-165
Author(s):  
Evangelos Boulougouris ◽  
Stuart Winnie ◽  
Apostolos Papanikolaou
Keyword(s):  
North Atlantic ◽  
Probabilistic Approach ◽  
Weather Conditions ◽  
Operating Conditions ◽  
Stability Assessment ◽  
Stability Criteria ◽  
The North ◽  
Damage Stability ◽  
Damaged Stability ◽  
The North Pacific

The operating conditions of modern warships, in the natural sea environment, have a significant influence on their survivability in the event that watertight integrity is lost. Up to now, the consideration of sea and weather conditions has been implicitly accounted for in a naval ship's damaged stability assessment. This article outlines a probabilistic approach to assessing a naval ship's damage stability, in which some of the limitations of the currently used damage stability criteria are identified, including the validity of the assumption of moderate sea states at the time of damage. An investigation of the operability of a frigate design found that there is a significant increase in the risk of a ship's loss when changing the operational area from the North Atlantic to the North Pacific. A remarkable additional finding of the study showed that the assumed distribution for the damage penetration has no significant effect on the ship's survivability because of the way modern combatants are designed.

Application of Seakeeping Analysis

1978 ◽  
Vol 15 (04) ◽  
pp. 416-431
Author(s):  
Bruce L. Hutchison ◽  
J. Thomas Bringloe
Keyword(s):  
Computer Program ◽  
Computer Method ◽  
Ship Motion ◽  
Engineering Practice ◽  
Post Processing ◽  
Motion Response ◽  
Response Characteristics ◽  
Motion Responses ◽  
Seakeeping Analysis

The paper gives a brief description of modern seakeeping analysis and discusses its application to problems encountered in engineering practice. The authors' experience with the computer program SCORES, for prediction, of ship motion responses, is reviewed, and examples of its application to typical problems are given. An appendix describes CARGO, a post-processing computer method developed to more fully utilize the motion response characteristics of the SCORES program.

GOALDS – Goal Based Damage Stability of Passenger Ships

2013 ◽  
Author(s):  
Apostolos Papanikolau ◽  
Rainer Hamann ◽  
Byung Suk Lee ◽  
Christian Mains ◽  
Odd Olufsen ◽  
...  
Keyword(s):  
Survival Probability ◽  
Regulatory Framework ◽  
Safety Standard ◽  
Major Step ◽  
Stability Properties ◽  
Cruise Ships ◽  
Damage Stability ◽  
Passenger Ships ◽  
Damaged Stability ◽  
The Eu

The new probabilistic damaged stability regulations for dry cargo and passenger ships (SOLAS 2009), which entered into force on January 1, 2009, represent a major step forward in achieving an improved safety standard through the rationalization and harmonization of damaged stability requirements. There are, however, serious concerns regarding the adopted formulation for the calculation of the survival probability of passenger ships and the associated required subdivision indices, particularly for RoPax and large cruise ships. The present paper outlines the objectives, the methodology of work and main results of the EU-funded FP7 project GOALDS (Goal Based Damage Stability, 2009-2012), which aims to address the above shortcomings by formulating a new rational, goalbased regulatory framework, properly accounting for the damage stability properties of passenger ships and the risk to people onboard.

An Investigation into the Effect of Bilge Keels to the Roll Motion Response of Fishing Vessel

2017 ◽  
Vol 862 ◽  
pp. 284-290
Author(s):  
Hasanudin ◽  
Jeng Horng Chen ◽  
I Ketut Aria Pria Utama ◽  
Haris Hendratmoko
Keyword(s):  
Model Experiment ◽  
Ship Motion ◽  
Roll Motion ◽  
Fishing Vessel ◽  
Motion Response ◽  
Merchant Ship ◽  
Calm Water ◽  
Excitation Force ◽  
Main Component ◽  
Bilge Keel

Stability of a ship is very influenced by ship’s roll motion, which is able to cause the ship to capsize. One of the main component which influence the roll motion, is the usage of motion damper at the ship’s hull. Bilge keel is a kind of passive damper whose construction is easy and does not require special system in the operation. The suitable bilge keel size is able to reduce excessive ship motion response when experiencing excitation force. This paper investigates the influence of bilge keel to the motion response of the ship by using a fishing vessel model with round bilge. The study was carried out by model experiment in the calm water and oblique wave using 6 types of bilge keel variation in its length and width. The results showed that the application of bilge keel is able to reduce about 37% motion response of the vessel; and the increase area of bilge keel also reduce the roll damping to 59%. It also can be concluded that common design bilge keel for merchant ship can be applied to the fishing vessel.

A Fast Numerical Method for Internal Flood Water Dynamics to Simulate Water on Deck and Flooding Scenarios of Ships

2013 ◽  
Author(s):  
Christian F. Janßen ◽  
Sebastian Bengel ◽  
Thomas Rung ◽  
Hendrik Dankowski
Keyword(s):  
Shallow Water ◽  
Lattice Boltzmann ◽  
Graphics Processing Units ◽  
State Of The Art ◽  
Water Dynamics ◽  
Lattice Boltzmann Model ◽  
Flood Water ◽  
Graphics Processing ◽  
Tank Sloshing ◽  
Boltzmann Model

The paper reports the extension of a Lattice Boltzmann model for the nonlinear viscous shallow water equations (NSW) and its application to the simulation of internal flood water dynamics. The solver is accelerated with the help of NVIDIAs CUDA framework to access the computational power of graphics processing units (GPGPUs). The model is validated with typical tank sloshing and cross flooding scenarios and the results are compared to analytical solutions and the results of a state-of-the-art shallow water solver on the basis of Glimm’s method.

A simulation model for ship response in flooding scenario

2016 ◽  
Vol 231 (1) ◽  
pp. 153-164 ◽  
Author(s):  
Maria Acanfora ◽  
Antonio Cirillo
Keyword(s):  
Experimental Studies ◽  
Water Dynamics ◽  
Lateral Acceleration ◽  
Ship Motions ◽  
Lumped Mass ◽  
Transient Stage ◽  
Numerical Result ◽  
Damage Stability ◽  
The Stability ◽  
Fully Coupled

Recent ship damages underline the importance of an accurate intact and damage stability analysis. The stability of ships is presently determined by applying quasi-static methods, neglecting dynamic effects; for flooding scenarios, flow calculations are not carried out either. In general, for damage cases, water dynamics inside the compartment affect ship motions. It has been observed that some kind of vessels could experience large roll motions due to the sudden water ingress after damage. In this article, a non-linear tool for damage stability evaluation is presented, including water dynamics in a flooded compartment. In particular the transient stage of flooding is investigated. The flooded water has been treated using the lumped mass approach. A new method has been developed and applied in this article in order to model the water motions: the freesurface is assumed to be no more horizontal but dependent on ship and flooded water accelerations. The developed method is intended to be an intermediate approach between the quasi-static method (uncoupled) and fully coupled method. In coupling the flooded water motions with ship motions, no more unknowns are introduced: only ship lateral acceleration is used to determine the freesurface inclination of the flooded water. A valuation is carried out, comparing the numerical result from the simulations with the experimental studies on a barge model. Additional applications are carried out on the free roll motion of the TNK tanker model.

scholarly journals Modeling of Flooding of Settlements During the Spring Flood

2021 ◽  
pp. 63-72
Author(s):  
Anna Klikunova ◽  
Tatyana Dyakonova ◽  
Ekaterina Agafonnikova ◽  
Ilya Makoveev ◽  
Mariya Kornaukhova ◽  
...  
Keyword(s):  
Spatial Data ◽  
Negative Impact ◽  
Parallel Implementation ◽  
Residential Buildings ◽  
Water Levels ◽  
Water Dynamics ◽  
Hydroelectric Power Station ◽  
Hydroelectric Power ◽  
Flood Water ◽  
River Bed

The problem of flooding of territories with flood waters for settlements of the Volgograd region is considered. A numerical model of flood water dynamics is constructed, taking into account the topography of the terrain. The simulation is based on two-dimensional shallow water equations. For computational experiments, a parallel implementation of the numerical scheme CSPH-TVD for NVIDIA graphics accelerators with CUDA technology is used. The digital model of the river-bed and floodplain relief is based on spatial data SRTM3 and SRTMGL, topographic maps of the area, longitudinal profiles of rivers. The water flow rates for the Buzuluk and Perevozinka rivers are determined and a hydrograph of the Volga hydroelectric power station is constructed for the given probabilities of exceeding the water level. Flood maps were obtained for the following localities: Novoannisky, Berezovka 1st, kh. Vyazovka. The maximum values of the depths for 1 %, 3 %, 5 %, 10 %, 25 % and 50 % of water security are presented. An analysis of the flood situation was carried out and appropriate engineering and protective measures for settlements were proposed. At maximum flood water levels, residential buildings of kh. Berezovka 1-I are not subject to flooding. In order to minimize the negative impact for the city of Novoanninsky, it is proposed to carry out timely clearing of the river-bed of the Perevozinka river from congestion. To protect from flooding ch. Vyazovka it is recommended to use diversion dyke.

Seti Space Missions

1997 ◽  
Vol 161 ◽  
pp. 761-776 ◽  
Author(s):  
Claudio Maccone
Keyword(s):  
Electromagnetic Waves ◽  
Space Missions ◽  
Gravitational Lens ◽  
The Sun ◽  
Space Antenna ◽  
Focal Distance ◽  
Large Space ◽  
The Earth ◽  
Space Antennas ◽  
New Space

AbstractSETI from space is currently envisaged in three ways: i) by large space antennas orbiting the Earth that could be used for both VLBI and SETI (VSOP and RadioAstron missions), ii) by a radiotelescope inside the Saha far side Moon crater and an Earth-link antenna on the Mare Smythii near side plain. Such SETIMOON mission would require no astronaut work since a Tether, deployed in Moon orbit until the two antennas landed softly, would also be the cable connecting them. Alternatively, a data relay satellite orbiting the Earth-Moon Lagrangian pointL2would avoid the Earthlink antenna, iii) by a large space antenna put at the foci of the Sun gravitational lens: 1) for electromagnetic waves, the minimal focal distance is 550 Astronomical Units (AU) or 14 times beyond Pluto. One could use the huge radio magnifications of sources aligned to the Sun and spacecraft; 2) for gravitational waves and neutrinos, the focus lies between 22.45 and 29.59 AU (Uranus and Neptune orbits), with a flight time of less than 30 years. Two new space missions, of SETI interest if ET’s use neutrinos for communications, are proposed.

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