A TWO-TIME SCALE FOR SHIP MANEUVERING IN A … Skejic.pdf · a seaway with application to joint...

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MARINTEK

CeSOS/AMOS 2013 Conference

Renato Skejic

A TWO-TIME SCALE FOR SHIP MANEUVERING IN A SEAWAY WITH APPLICATION TO JOINT

MANEUVERS OF TWO SHIPS

May 27 - 29, 2013.

INTRODUCTION UNIFIED MODEL NUMERICAL STUDIES CONCLUSIONS

Skejic: A Two – Time Scale for Ship Maneuveing in a Seaway with … AMOS

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CONTENT IntroductionUnified seakeeping and maneuvering model

Numerical studies

Conclusions

• Modular concept• Summary

• Particulars



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INTRODUCTION



The ship maneuvering characteristics:- calm water (traditional approach, early design stages)- seaway (the environmental loads: wind/waves/current/ice)

Combined seakeeping and maneuvering analysis is important for:- maneuvers and close proximity marine operations carried out in complex

environmental conditions (waves, wind, current; ice)in order to satisfy requirements for:

operability, feasibilitysafety, efficiency



(Examples: passing, meeting,

• Involve: the floating/stationary objects of different size with/without the forward speed(s)and with/without the propulsive, maneuvering and control capabilities

• Performed in: coastal or open and deep waters

overtaking, replenishment, lightering, inspection maneuver)

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• Carried out: under specific conditions and requirements (low, moderate speeds) in order to accomplish given tasks in different regional and environmental zones

- presence of combined effects of the weather conditions (waves, wind, current, ice), constrained waters with limited water depth and speed of the objects

Close proximity marine operations:

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Formulation: Two-Time Scale approach; Skejic and Faltinsen (2008, 2013)

Model assumption:

Communication between the scales:

• slowly varying (nonlinear maneuvering)

• rapidly varying (seakeeping; regular and irregular waves)

- slowly varying parameters through modular maneuvering concept (physical decomposition of the interacting ship(s)/propeller(s)/rudder(s)/flow effects)

- Froude number Fn <≈ 0.25

Model particulars: - forward speed drop- maneuvers with moderate/high rudder angles



- based on the rational approach (real time)

UNIFIED SEAKEEPING AND MANEUVERING MODEL

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• Maneuvering module

Modules are:• Resistance and propulsion

- ‘Holtrop – Mennen’ (1982) method(total calm water resistance with/without the finite water depth/channel effects)

- Selected type of propellers – Carlton (1994), Yasukawa (2006, 2009)

- Generalized 4 DOF slender body theory model – Söding (1982)- 6 DOF slender body theory and 3D model with the finite water depth/channel effects

– Skejic (2012, 2013)

• Nonlinear viscous cross-flow drag module

• Rudder module

(based on the Cross-flow principle - Faltinsen, 1990; 2005)

(Selected type of rudders - Ankudinov et al., 1993; Kijima et al., 1993)



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• Uniform current module

• Wind load module (work in progress)

- Horizontal and/or vertical plane(s) – Artyszuk (2004)

- Newman and Tuck (1974) slender body theory (infinite fluid)- Xiang and Faltinsen (2010) 3D model (infinite fluid)

• Hydrodynamic interaction loads module (2 ships) – calm water

Work in progress: inclusion - free surface and/or the finite water depth/channel effects

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• Motion control modules (‘autopilots’)Fossen and Breivik (2009, 2011)

Type II

Type I

- maneuvers for abeam, tandem configurations - overtaking, meeting maneuvers

- specific type of maneuvers with the constrains

Ship to be lightered

SYNCHRONIZATIONMODULE

Lighteringship

Position and Velocity



HeadingControl

Heading Reference

SpeedControl

Speed Reference

STEERINGMODULE

Transverse Reference

Longitudinal Reference


Propulsion CommandSpeed

Rudder Command

Heading Angle and Rate

Type I

Type II



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Skejic: A Two – Time Scale for Ship Maneuveing in a Seaway with …

• Mean 2nd order wave loads module; Single ship (Regular waves – deep water)- slender body theories- 3D theory, Xiang and Faltinsen (2011)

AMOS

• Slow - drift 2nd order wave loads module; Single ship (Irregular waves – deep water)- slender body theories, Skejic and Faltinsen (2013) based on Newman (1974) approx.- 2D spectral formulation of a seaway S(ω) (long-crested wave field)

- surge

- sway

- yaw

Time (s)

H1/3 = 3.0 m, T2 = 10.0 sH1/3 = 4.0 m, T2 = 10.0 sH1/3 = 5.0 m, T2 = 10.0 sH1/3 = 7.0 m, T2 = 10.0 sH1/3 = 8.0 m, T2 = 10.0 s

ω (rad/s)

S(ω)

(m2 /s

)

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Hydrodynamic interaction loads module; Two ships (Irregular waves)

Work in progress: 3D spectral formulation of a seaway S(ω,β) Short-crested irregular wave field

- 3D theory, Xiang and Faltinsen (2011)

Note: In two (or multiple) ships configuration the hydrodynamic interaction (calm water/waves) can be neglected or taken into account depending on the relative forward speed and position between two ships.

The finite water depth/channel effects in waves

• Hydrodynamic interaction loads module; Two ships (Regular waves – deep water)

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Resistanceand

Propulsion

Rudder(s)

ViscousDrag

ExternalLoading

Singlefloating objects

(mono-, multihulls)Ships,

Wind Turbines,Docks, etc.

Two or Multiplefloating objects

Unified Model – Structure, Capabilities and Applications

BASEUnified Model

Calm waterInfinite/Finite water depth

Channel effects

Operabilityanalysis

Environmentalanalysis

Capabilities

Safetyanalysis

Efficiencyanalysis

Feasibilityanalysis

Applications

Short timeduration

Long timeduration

Weather routingCollision risk (avoidance) evaluation

Human response versus complexity of marine operation(s) and/or environmental conditionsOperational evaluation concerning the environmental conditions and/or complexity of marine operation(s)

Pollution aspects

CurrentIceWind

Waves

MotionControl

'autopilots' Calmwater

WavesWind

Current

Ice

Hydrodyn.Interaction

Dynamics:mooringfenders

Additionalmodule(s)?

MO

DULA

R

C

NO

E

T

C

P

Unified Seakeeping and Maneuvering Model – Summary

Economic aspects related to fuel consumptions and associated costs

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NUMERICAL STUDIESMain particulars ‘MARINER’ ‘S7-175’ ‘KVLCC2’ ‘Aframax’ ‘Storage facility’ ‘MARINER-(1:4)’

LPP (≡ L) 160.934 m 175.0 m 320.0 m 230.0 m 50.0 m 40.23 mB 23.165 m 25.4 m 58.0 m 42.0 m 43.3 m 5.78 m

T (even keel) 7.468 m 9.50 m 20.8 m (full load) 7.5 m (ballast) 5.0 m 1.867 mCB 0.61 0.5716 0.8097 0.78 0.75 0.61

COG (0.0, 0.0, - 2.45) m (0.0, 0.0, 0.02) m (0.0, 0.0, - 8.06) m (0.0, 0.0, - 2.88) m (0.0, 0.0, 0.0) m (0.0, 0.0, - 0.696) mCOB (0.0, 0.0, - 3.48) m (0.0, 0.0, - 4.27) m (0.0, 0.0, - 10.87) m (0.0, 0.0, - 3.6) m (0.0, 0.0, - 2.3) m (0.0, 0.0, - 0.87) m

Propellers 1 (6.7 m) 4 bladesWAGENINGEN – B SER.

CustomYasukawa (2006, 2009)

1 (9.86 m) 5 bladesWAGENINGEN – B SER.

1 (6.8 m) 5 bladesWAGENINGEN – B SER.

N/A 1 (1.198 m) 5 bladesWAGENINGEN – B SER

Rudders 1 (25.25 m2) 1 (32.46 m2) 1 (174.74 m2) 1 (57.87 m2) N/A 1 (2.84 m2)Thrusters N/A N/A N/A N/A N/A N/A

Main characteristics of the floating objects

‘KVLCC2’Moeri tanker

‘Aframax’ ‘Storage facility’

‘MARINER-(1:4)’

‘MARINER’

‘S7- 175’ (‘SR 180’ )

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Calm and deep water

CalculationYasukawa (2006, 2009)

‘S7-175’ (‘SR 180’ ) hull: – 35.0°Port Turnmaneuver with approach forward speed12.079 knots in calm and deep water

TRANSFER IN METERS

AD

VAN

CE

INM

ETE

RS

-200 0 200 400 600 800 1000 1200-800

-600

-400

-200

0

200

400

600

800

CalculationFull Scale Trial

‘MARINER’ hull: 20.9° Starboard Turnmaneuver with approach forward speed15.4 knots in calm and deep water

SINGLE SHIP (mono-, multihulls)

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(kno

ts)

Time (s)

uYasukawa (2006, 2009)

v

(deg

.)

Time (s)

-δ

β

Yasukawa (2006, 2009)

(deg

./s)

Time (s)

rYasukawa (2006, 2009)



χ (deg.) χ (deg.) χ (deg.)

RX /(ρgζa2B2/L) RY /(ρgζa

2B2/L) MZ /(ρgζa2BL)

Regular waves (deep water)λ/L = 0.7, η = 270°

ζa (m)

Yasukawa (2006, 2009)

η = 270°

‘S7-175’ (‘SR 180’ ) hull: – 35.0°Port Turn maneuver with approach forward speed 12.079 knots in regular waves with wave amplitude 1.75 maς =

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‘MARINER’ hull: 20.9° Starboard Turn maneuver with approach forward speed 15.4 knots in regular waves with wave amplitude 1.5 maς =

TRANSFER IN METERS

ADV

ANC

EIN

MET

ERS

0 400 800 1200

-800

-400

0

400

800η = 150°

Calm waterFaltinsen et al. (1980), λ/L=1.0Salvesen (1974), λ/L=1.0Asymptotic theoryFaltinsen et al. (1980),λ/L=0.45



RX /(ρgζa2B2/L)

χ (deg.)-600-450-300-1500150

-10

-8

-6

-4

-2

0

-600-450-300-1500150

-30

-20

-10

0

10

20

RY /(ρgζa2B2/L)

χ (deg.)

MZ /(ρgζa2BL)

-600-450-300-1500150

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

χ (deg.)

Regular waves (deep water) - continue

ZZ PATH

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Uncertainty and mean value of ship(s) maneuveringsimulations in seaway

Irregular waves (deep water)

‘MARINER’ hull: 20.9° Starboard Turn maneuver with approach forward speed 15.4knots in irregular waves (ISSC,1978 spectrum: H1/3 = 7.0 m, T2 = 10.0 s)

η = 150°

Calm water

S1S2S3S4S5S6

Ship paths forrandom seeds:

β – calm waterβ – for random seeds: S1, S2, S3, S4, S5 and S6

(deg

.)

Time (s) Time (s)

r – calm waterr – for random seeds: S1, S2, S3, S4, S5 and S6

(deg

./s)

Time (s)

v – calm waterv – for random seeds: S1, S2, S3, S4, S5 and S6

u – calm wateru – for random seeds: S1, S2, S3, S4, S5 and S6

(kno

ts)

C PATH

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Calm and deep water

The close proximity maneuvers• Particulars: - short or long time duration

- carried out in different environmental conditions- increased collision hazard due to the hydrodynamic interaction effects

2. 3. 4. 5.

High collision risk

ApproachAbeam

Departure

• Overtaking maneuver

1.1.1.

‘Aframax’

‘KVLCC2’

OC PATHAND PATHCOLLISION

TWO SHIPS (mono-, multihulls)

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- lightering ship ‘Aframax’ - (RED SHIP), initial position (200.0, - 200.0) m with the approach speed of 6.0 knots

- ship to be lightered ‘KVLCC2 – Moeri tanker’ - (BLUE SHIP), initial position (800.0, 400.0) m with the approach speed of 4.0 knots

• Lightering maneuver - configuration

- desired: transverse clearance 12.5 m, longitudinal distance 20.0 mC LIGHT FORCE

MOMENTPATH

- inspection ship scaled ‘MARINER - (1:4)’ - (RED), initial position (- 100.0, 100.0) m with the approach speed of 6.0 knots

- floating object ‘Storage facility’ - (BLUE), initial position (10.07, - 3.17) m

• Inspection maneuver - configuration

- desired: ship |steady turning radius| = 60.0 m- calm water (the floating object is moored)

INSPECT 2

- uniform current: |VC| = 0.2916 knots, ψC = 315° (the floating object isfree to drift)

INSPECT 1

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Regular waves (deep water)

- lightering ship ‘Aframax’ - (RED SHIP), initial position (200.0, - 200.0) m with the approach speed of 6.0 knots

- ship to be lightered ‘KVLCC2 – Moeri tanker’ - (BLUE SHIP), initial position (800.0, 400.0) m with the approach speed of 4.0 knots

• Lightering maneuver - configuration

- desired: transverse clearance 12.5 m, longitudinal distance 20.0 m,constant heading angle 22.5°

- incident waves: η = 157.5° (port head beam sea), λ = 287.99 m, ζa = 1.5 m

W LIGHT FORCEMOMENT

PATH

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CONCLUSIONS

Maneuvering of a single ship in a seaway

Close proximity maneuvers and complex marine operations in a seaway

• Without ‘autopilot’ motion control system (mimics qualified bridge and deckpersonnel) the close proximity maneuvers and complex marine operations incalm water/seaway with zero collision risk tolerance can not be accomplished

• The hydrodynamic interaction loads alone or combined with other weather conditions(waves, wind, current, ice) have significant influence on the maneuvering behavior ofobjects involved in the close proximity maneuvers and complex marine operations

• Unified seakeeping and maneuvering model based on slowly varying maneuveringtime scale accounts for the wave field loads obtained on rational way fromseakeeping analysis

• Incident regular/irregular waves can have significant influence on ship maneuvering• Due to complexity of the ship maneuvering problem in a seaway further investigations

in both; theoretical and experimental directions are needed

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Faltinsen, O. M., Minsaas, K., Liapis, N. and Skjørdal, S. O. (1980) Prediction of resistance and propulsion of a ship in a seaway. In Proc. of the13th Symp. on Naval Hyd., pp. 505–529, Tokyo, Japan.

Faltinsen, O. M. (1990) Sea Loads on Ships and Offshore Structures. Cambridge University Press.Faltinsen, O. M. (2005) Hydrodynamics of High–Speed Marine Vehicles. Cambridge University Press.Faltinsen, O.M. MODELLING OF MANOEUVRING WITH ATTENTION TO SHIP-SHIP INTERACTION AND WIND WAVES. 2nd Int.

Conference on Ship Manoeuvring in Shallow and Confined Water: Ship to Ship Interaction, May 18-20, 2011, Trondheim, Norway.Holtrop, J. and Mennen, G. G. J., 1982, “An approximate power prediction method”, Int. Shipbuild. Progr. 29.Kashiwagi, M. (1992) 'Added Resistance, Wave–Induced Steady Sway Force and Yaw Moment on an Advancing Ship' Ship Tech. Res. (39), pp. 3–

16.Newman, J. N. (1977) Marine Hydrodynamics. Cambridge: The MIT Press.Skejic, R. and Berg, T. E., 2009, “Hydrodynamic Interaction Effects during Lightering Operation in Calm Water – Theoretical Aspects” In

Proceedings of the International Conference on Marine Simulations and Ship Maneuverability - MARSIM 2009, Panama City, Panama.Skejic, R. and Berg, T. E., 2010, “Combined Seakeeping and Maneuvering analysis of a Two Ship Lightering Operation” In Proceedings of the 29th

International Conference on Ocean, Offshore and Arctic Engineering – OMAE 2010, Shanghai, China.Skejic, R. and Faltinsen, O.M. (2008) A unified seakeeping and maneuvering analysis of ships in regular waves. J. of Marine Science and

Technology, DOI 10.1007/s00773-008-0025-2, http://www.springerlink.com/content/88373xm3g12h4067/fulltext.pdf.Skejic, R. and Faltinsen, O.M. (2013) Maneuvering behavior of ships in irregular waves. OMAE 2013, Nantes, France.Skejic, R., 2008, “Maneuvering and Seakeeping of a Single Ship and of Two Ships in Interaction”, PhD thesis, NTNU Trondheim, Norway.Xiang, X. and Faltinsen, O.M. TIME DOMAIN SIMULATION OF TWO INTERACTING SHIPS ADVANCING PARALLEL IN WAVES.

OMAE 2011, June 19-24, 2011, Rotterdam, The Netherlands.Yasukawa, H., 2006, “Simulations of ship maneuvering in waves (1st report: turning motion)”, Journal of the Japan Society of Naval Architects and

Ocean Engineers, 4:127–136.Yasukawa, H. and Nakayama, Y., 2009, “6-DOF motion simulations of a turning ship in regular waves”, International Conference on Marine

Simulation and Ship Manoeuvrability, MARSIM’09, Panama City, Panama.

References

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MARINTEK

CeSOS/AMOS 2013 Conference

Renato Skejic

A TWO-TIME SCALE FOR SHIP MANEUVERING IN A SEAWAY WITH APPLICATION TO JOINT

MANEUVERS OF TWO SHIPS

May 27 - 29, 2013.



A TWO-TIME SCALE FOR SHIP MANEUVERING IN A … Skejic.pdf · a seaway with application to joint...

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