8/3/2019 Beban Fluida Pada Kapal Rusak_Marine
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The problem
Figure 3: Loss of vessel scenarios (Paik & Thayamballi,
1998), highlightedelements are within the scope of this
project.
Bac kground
An area of research that is gathering momentum in the marine
industry is that ofthe effect of damage on ship structures.
Research into the behaviour of damagedships began in the mid
nineties as a result of Ro-Ro disasters (e.g. Estonia in1994). Due
to the way the Estonia sank, this early research mainly focused
ontransient behaviour immediately after the damage takes place, the
prediction ofcapsize, and of large lateral motions. Further
research efforts, headed by the UKMoD, were sparked when HMS
Nottingham ran aground tearing a 50m hole frombow to bridge,
flooding five compartments and almost causing the ship to sinkjust
off Lord Howe Island in 2002. A joint collaboration between MoD,
LloydsRegister, UCL, and the University of Southampton is currently
being formed tobring together research efforts in this area, the
following is a question posed bythe MoD that is the subject of this
EngD research.
For a given amount of underwater damage (e.g. collision or
torpedo/mine hit),what will be the progressive damage spread if the
ship travels at x knots? ORfor a given amount of underwa ter
damage, w hat is the maximum speed atwhich the ship can travel
without causing additional damage?
Figure 1: HMS Nottingham stuck on rocks (left), Close up of
damage once liftedfrom the water (right)
The aim of this EngD research is to model the fluid loading on
ships withunderwater damage, both the global ship loads due to
additional weight of thefloodwater on the structure including the
effect of the ingress/egress of the floodwater; and local
hydrodynamic loads on the area around the damage location toassess
potential damage propagation.
Fluid Loads on Damaged ShipsChristian Wood -
[email protected] - School of Engineering Sciences
Lloyds Register and Ministry of Defence
Supervisors Dr. D. Hudson, Dr. M. Tan and Mr. P. James (Lloyds
Register)
FSI Away Day 2009
Research
Existing research has seen models ranging from 1 degree of
freedom non linearequations of motions to 6 degree of freedom panel
methods with simple floodingmodels. Currently the main failings of
existing research include inadequateprediction of roll damping,
floodwater motions and motions of a damaged ship inan irregular
seaway. This will be achieved using ANSYS CFX coupled with a
rigidbody motions code that will resolve the physics of the roll
damping, sloshingbehaviour of the floodwater and ship motions
together, where the non-linearinteractions will be included
naturally. The project will include experimentation tovalidate
component parts of the full CFD model.
Figure 2: Floating body experiment (left), CFD coupled with
floating body motioncode (right) from Milovan Peric, CFD Solvers in
marine context: research andapplications, CeSOS CFD Workshop,
Trondheim, 2007.
C ompone nt parts
Dambreak modelling of violent free surface motions
Figure 4: Comparison of results from (Abdolmaleki, 2004) in red
and results fromANSYS CFX 11.0 in blue.
Rigid Body Motions - 2 DoF example
Figure 5: Grid and results of a rigid ship body in waves.
FLUID STRUCTURE INTERACTIONS
RESEARCH GROUP
Loss of Vessel
Side Shell Failure Hatch Cover Failure Corrosion Fatigue Crack
Local Dent
Water Ingress
Partial Loss ofStructure
Hold Flooding
Decrease of HullGirder Strength
Increase of HullGirder Loads
Transverse
Bulkhead Failure
ProgressiveFlooding to
Adjacent Holds
Loss of Stability Loss of Reserve Buoyancy Hull Girder
Collapse
Conclusions
A model of higher physical fidelity is needed to accurately
represent the transientbehaviour of a damaged ship
F uture work
Continuation with flooding simulations; tank filling and
sinkable objects
Continuation with assessment of rigid body motion in a seaway
simulations Parametric study of damage and seaway conditionsfor
specific hull types Validation of simpler cases using
experiment
