Progressive flooding of a damaged passenger ship

Pekka Ruponen

Progressive flooding of a damaged passenger ship

Julkaisun otsikon käännös: Progressiivinen vuoto vaurioituneessa matkustajalaivassa

Pekka Ruponen

Tutkimustuotos: Doctoral Thesis › Monograph

Abstrakti

Työssä tutkittiin aikatason simuloinneilla progressiivisen vuodon etenemistä vaurioituneessa matkustajalaivassa. Tätä tarkoitusta varten kehitettiin uudentyyppinen laskentamenetelmä. Matkustajalaivan vesitiiviissä osastoissa on usein lukuisia monimutkaisia tiloja ja niitä yhdistäviä aukkoja. Lisäksi ilmanvaihto void-tiloissa on usein rajoitettu pienten ilmaputkien takia, joten vuoto voi aiheuttaa myös ilman kokoonpuristumista. Nämä tekijät ovat merkittäviä simuloitaessa progressiivista vuotoa ajan suhteen tarkasti. Kehitetty uudentyyppinen laskentamenetelmä perustuu painekorjaustekniikkaan. Tämä iteratiivinen ja implisiittinen menetelmä soveltuu hyvin ajan suhteen tarkkaan laskentaan. Vuotoveden etenemisen laskenta pohjautuu siinä hydrostaattisiin paineisiin, eli veden korkeuksiin, vuodon saaneissa tiloissa. Laajalti käytettyä hydraulista mallia (Bernoullin yhtälö) sovelletaan virtausnopeuksien laskentaan. Laivaa käsitellään limitettynä ja rakenteettomana laskentahilana, jossa hydrostaattinen paine ja ilmanpaine ratkaistaan tilojen keskellä ja virtausnopeudet tiloja yhdistävissä aukoissa. Myös ilman vastapaine ja siitä seuraavat ilmavirtaukset voidaan ratkaista. Kaikki nestepinnat oletetaan horisontaaleiksi tasoiksi. Tutkimuksen pääpaino on vuodon etenemisen laskennassa, joten laivan liikkeiden määrittämiseen käytetään yksinkertaista kvasistaattista lähestymistapaa. Tässä hyödynnettiin NAPA-ohjelmiston standardimenetelmiä. Lisäksi oletetaan, että meri on tyyni. Kehitetty simulointimenetelmä on perusteellisesti validoitu vertaamalla laskennallisia tuloksia laatikkolaivan mallilla tehtyihin mittauksiin vuodon etenemisestä ja ilman puristumisesta. Tulokset osoittavat hyvän vastaavuuden laskennan ja mittausten välillä. Menetelmän soveltuvuutta käytäntöön on testattu simuloimalla poikittaisvuotoa ja laajaa progressiivista vuotoa 40 000 GT:n kokoisessa matkustajalaivassa. Progressiivisen vuodon tapauksessa on otettu huomioon myös vuoto vaurioituneiden ja sortuneiden rakenteiden läpi sekä hidas alasvirtaus monimutkaisessa ja laajassa tilojen ja aukkojen muodostamassa systeemissä.

Julkaisun otsikon käännös	Progressiivinen vuoto vaurioituneessa matkustajalaivassa
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Matusiak, Jerzy, Vastuuprofessori
Kustantaja	Helsinki University of Technology
Painoksen ISBN	978-951-22-9012-3
Sähköinen ISBN	978-951-22-9013-0
Tila	Julkaistu - 2007
OKM-julkaisutyyppi	G4 Monografiaväitöskirja

Tutkimusalat

progressiivinen vuoto
vuotovakavuus
painekorjaus
matkustajalaiva

Pääsy asiakirjaan

http://urn.fi/urn:nbn:fi:tkk-010597

Siteeraa tätä

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title = "Progressive flooding of a damaged passenger ship",

abstract = "Progressive flooding inside a damaged passenger ship was studied with time-domain simulations. A novel computational method was developed for this purpose. Typically, the layout of the watertight compartments in this ship type contains numerous openings and rooms with complex geometry. In the voids the flooding can also result in air compression since the ventilation of these rooms is restricted due to the relatively small air pipes. These factors are significant for time-accurate simulation of progressive flooding. The developed method is based on pressure correction technique. This iterative and implicit approach is suitable for time-accurate simulations. The progress of the floodwater is considered on the basis of the hydrostatic pressure (i.e. the water height) in the flooded rooms. The widely used hydraulic model, based on Bernoulli's equation, is used for the calculation of the flow velocities. The pressure-correction equation is formed from the conservation of mass and the linearization of Bernoulli's equation. The ship is considered as a staggered and unstructured grid, where the hydrostatic and air pressures are solved in the centers of the rooms and the flow velocities in the openings. Also the counter pressure due to air compression and the resulting airflows can be solved. All water levels are considered to be flat and parallel to the sea level. The main emphasis of the study is on the calculation of the flooding inside the damaged ship, and therefore, a simple quasi-stationary approach is used for the evaluation of the ship motions. The standard procedures of the NAPA software are utilised for this. In addition, it is assumed that the sea is calm. The developed simulation method has been extensively validated by comparing simulation results with the measurement data from model tests for progressive flooding and air compression in a damaged box-shaped barge. The results of the validation show very good correspondence between the simulations and the measurements. The applicability of the developed simulation method has been tested by performing simulations of cross-flooding and extensive progressive flooding for a 40 000 GT passenger ship design. The latter test case involves flooding through leaking and collapsed structures and slow down-flooding in a large and complex system of rooms and openings.",

keywords = "progressive flooding, damage stability, pressure correction, passenger ship, progressiivinen vuoto, vuotovakavuus, painekorjaus, matkustajalaiva, progressive flooding, damage stability, pressure correction, passenger ship",

author = "Pekka Ruponen",

year = "2007",

language = "English",

isbn = "978-951-22-9012-3",

series = "TKK dissertations",

publisher = "Helsinki University of Technology",

number = "94",

address = "Finland",

school = "Aalto University",

}

TY - BOOK

T1 - Progressive flooding of a damaged passenger ship

AU - Ruponen, Pekka

PY - 2007

Y1 - 2007

N2 - Progressive flooding inside a damaged passenger ship was studied with time-domain simulations. A novel computational method was developed for this purpose. Typically, the layout of the watertight compartments in this ship type contains numerous openings and rooms with complex geometry. In the voids the flooding can also result in air compression since the ventilation of these rooms is restricted due to the relatively small air pipes. These factors are significant for time-accurate simulation of progressive flooding. The developed method is based on pressure correction technique. This iterative and implicit approach is suitable for time-accurate simulations. The progress of the floodwater is considered on the basis of the hydrostatic pressure (i.e. the water height) in the flooded rooms. The widely used hydraulic model, based on Bernoulli's equation, is used for the calculation of the flow velocities. The pressure-correction equation is formed from the conservation of mass and the linearization of Bernoulli's equation. The ship is considered as a staggered and unstructured grid, where the hydrostatic and air pressures are solved in the centers of the rooms and the flow velocities in the openings. Also the counter pressure due to air compression and the resulting airflows can be solved. All water levels are considered to be flat and parallel to the sea level. The main emphasis of the study is on the calculation of the flooding inside the damaged ship, and therefore, a simple quasi-stationary approach is used for the evaluation of the ship motions. The standard procedures of the NAPA software are utilised for this. In addition, it is assumed that the sea is calm. The developed simulation method has been extensively validated by comparing simulation results with the measurement data from model tests for progressive flooding and air compression in a damaged box-shaped barge. The results of the validation show very good correspondence between the simulations and the measurements. The applicability of the developed simulation method has been tested by performing simulations of cross-flooding and extensive progressive flooding for a 40 000 GT passenger ship design. The latter test case involves flooding through leaking and collapsed structures and slow down-flooding in a large and complex system of rooms and openings.

AB - Progressive flooding inside a damaged passenger ship was studied with time-domain simulations. A novel computational method was developed for this purpose. Typically, the layout of the watertight compartments in this ship type contains numerous openings and rooms with complex geometry. In the voids the flooding can also result in air compression since the ventilation of these rooms is restricted due to the relatively small air pipes. These factors are significant for time-accurate simulation of progressive flooding. The developed method is based on pressure correction technique. This iterative and implicit approach is suitable for time-accurate simulations. The progress of the floodwater is considered on the basis of the hydrostatic pressure (i.e. the water height) in the flooded rooms. The widely used hydraulic model, based on Bernoulli's equation, is used for the calculation of the flow velocities. The pressure-correction equation is formed from the conservation of mass and the linearization of Bernoulli's equation. The ship is considered as a staggered and unstructured grid, where the hydrostatic and air pressures are solved in the centers of the rooms and the flow velocities in the openings. Also the counter pressure due to air compression and the resulting airflows can be solved. All water levels are considered to be flat and parallel to the sea level. The main emphasis of the study is on the calculation of the flooding inside the damaged ship, and therefore, a simple quasi-stationary approach is used for the evaluation of the ship motions. The standard procedures of the NAPA software are utilised for this. In addition, it is assumed that the sea is calm. The developed simulation method has been extensively validated by comparing simulation results with the measurement data from model tests for progressive flooding and air compression in a damaged box-shaped barge. The results of the validation show very good correspondence between the simulations and the measurements. The applicability of the developed simulation method has been tested by performing simulations of cross-flooding and extensive progressive flooding for a 40 000 GT passenger ship design. The latter test case involves flooding through leaking and collapsed structures and slow down-flooding in a large and complex system of rooms and openings.

KW - progressive flooding

KW - damage stability

KW - pressure correction

KW - passenger ship

KW - progressiivinen vuoto

KW - vuotovakavuus

KW - painekorjaus

KW - matkustajalaiva

KW - progressive flooding

KW - damage stability

KW - pressure correction

KW - passenger ship

M3 - Doctoral Thesis

SN - 978-951-22-9012-3

T3 - TKK dissertations

PB - Helsinki University of Technology

ER -

Progressive flooding of a damaged passenger ship

Abstrakti

Tutkimusalat

Pääsy asiakirjaan

Sormenjälki

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