Transcript MANOEUVRING OF HIGH SPEED SHIPS

MANOEUVRING OF HIGH-SPEED
SHIPS
Mr.E. ARMAOGLU
SSRC, Dept of Naval Architecture & Marine Engineering, Universities of
Glasgow and Strathclyde, UK
Presentation Outline
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Introduction - Aims
Types of Instabilities of HSC
Current Mathematical Model
The Path to be Followed
Current Research Progress
Introduction
Manoeuvring of High Speed Craft from Stability
and Safety Point of View
WATCH OUT FOR COLLISIONS!!!
Prevention (IMO 1997):
• Sufficient Controllability
• Adequate Dynamic Stability
• Sufficient Manoeuvrability
Introduction
Recommendation From The 22nd ITTC Specialist
Committee of High Speed Marine Vehicles
Problems relating to High-Speed roll, pitch and
directional stability anomalies must be solved
with accompanying model tests to find the effect
of Position of Centre of Gravity and GM on
course-stability and capsize.
Types of Instabilities of HSC
INSTABILITIES DEFINED BY ITTC and more…
• Pure Loss of Stability (Loss of GM due to wave
system)
• Course Keeping (e.g. Broaching, Parametric
Rolling)
• Bow-Diving
• Chine-Tripping
• Spray-Rail Engulfing
• Porpoising
• Additionally Chine-walking and Corkscrew
Current Mathematical Model
Manoeuvring Mathematical Model by Dr. Ayaz Features:
• 6 Degrees of Freedom
• Frequency Dependent Coefficients
• Incorporating Memory Effects
• No Restrictions on Motion Amplitudes
• Axis System That Allows Combination of
Seakeeping and Manoeuvring Models
Mathematical Model
System of Coordinates
Mathematical Model
Mathematical Model
Equations of Motion
  ω V )  X
m (V
G
G
F
  ω H  X
H
G
G
M
Where m is the mass of a ship, HG the momentum about the
centre of gravity,  the angular velocity, VG the linear velocity
and XF, XM the external force and moment vectors, respectively.
Mathematical Model
Equations of Motion
  VR)  X'
m(U
  UR)  Y'
m(V

mW
 Z' mg
1 
K` (I yy  I xx )[sin2θ (QP  R)  cos 2θ QR]
2
  I RQ
 (I xx cos2 θ  I yy sin 2 θ) P
yy
1 2
R )]
2

 (I xx cos2 θ  sin 2 θ)RP  I yy Q
M` (I yy  I xx )[sin2θ (
1 
N'  (I xx  I zz )[sin 2θ (QR  P)  cos2θ QP ]
2

 (I xx sin 2 θ  I zz cos2 θ) R
Mathematical Model
Equations of Motion
X : ζ a , ξ G , x, y,z, u, v, w, p,q, r, φ, θ, ψ, δ
T
 denotes rudder or pod angle, g and a
represent horizontal and vertical component of
wave amplitude
  B (X)X
  C (X)X  F(ζ , X, X
 ,X
 )
(M  A)X
w
where, M is inertia Matrix, A is added inertia
matrix, B is damping coefficient matrix, C is
restoring coefficient matrix, F is external force
vector and w is wave amplitude.
Mathematical Model
External Forces
X'  X W  X H  X RS  X RD  X P
Y '  YW  YH  YRD  YP
Z'  Z W  Z H
K' K
W
 K H  K RD  K P
M'  M W  M H
N '  N W  N H  N RD  N P
W indicates wave forces and moments, H indicates
hull (manoeuvring) forces and moments and
radiation forces and moments for vertical motions,
RS indicates resistance forces, RD indicates rudder
forces and moments and P indicates propeller
forces and moments
Mathematical Model
External Forces [Automatic Control]
The standard proportional-differential (PD) autopilot
is employed in this model

δ R  t r δ R  k1 (ψ  ψ R )  k 2 ψ
R is the actual rudder angle, R is the desired
heading angle, k1 is yaw angle gain constant, k2 is
yaw rate gain constant and tr is the time constant in
rudder activation
The Effect of the New Mathematical Model on
Motion
The Effect of the New Mathematical Model on
Motion
The Path to be Followed
• Steady Manoeuvring Motion
Effect of Running Attitude on Manoeuvring
Hydrodynamic Forces at High Speed
• Unsteady Manoeuvring Motion
Memory Effects
• Oscillatory Instabilities
Effect of Vertical Lift Force on Stability Motion
• Non-Oscillatory Instabilities
Effect of Vertical Lift Force on Manoeuvring
Hydrodynamic Forces
An Oscillatory Type Instability for a High-Speed
Craft: Coupling Between Horizontal and
Vertical Motions
Experiment Video from Osaka Prefecture University is Presented with
Permission of Dr. Toru Katayama
The Challenge
HAVING A MATHEMATICAL
MODEL TO ACCOUNT FOR
ALL THESE PROBLEMS IN
EXTREME RANDOM WAVES
FOR HIGH-SPEED CRAFTS
The Current Research Progress
Investigation of the behavior of high-speed craft
at irregular seas based on this mathematical
model is progressing. Further steps include the
addition of vertical lift component and coupling
effects between vertical and horizontal motions to
our mathematical model.
Questions?
THANK YOU FOR
LISTENING 