large trimaran concepts and technology...

1

SD5-HIS Joint Meeting, April 1, 2008

Large Trimaran Concepts and Large Trimaran Concepts and Technology ElementsTechnology Elements

By Dr. Igor Mizine, CSC Advanced Marine Center

Presentation at Joint SD-5 Panel and International Hydrofoil Society Meeting April 1, 2008

2


Presentation ContentBackground: HALSS Mission and CapabilitiesHALSS Concept Design Characteristics

General & Machinery ArrangementProductivity Studies

Performance Validation & Selected Technology ElementsHull Forms and Resistance Model TestsSeakeeping

Summary

HALSS Technology and Concept Evaluation Team:HALSS Technology and Concept Evaluation Team:

NSWCCD Viking Systems

SPAR Associates Global Management Partners

3


Design Approach and Trimaran RationalMultihull (Trimaran) ships allow high slenderness of the hulls to

reduce resistance at hump Froude numbers. Design goal is to find the best compromise between increase of wetted surface, maximum possible slenderness and resistance interference between the hulls. There is a flexibility in Trimaran configuration, which helps finding best solution.

Trimaran has substantially higher stowage capacity than equivalent monohull. Trimaran is conducive to transport high area/volume consuming payloads: Light Army and USMC equipment, hellos, sustainment, troops. In commercial application – Trimaran is the best concept for carrying cargo on wheels, allowing enough spaces forinternal maneuvers at loading and offloading. Excessive deck area is useful for aerial support.

For high speed and large sizes, Trimaran allows the propulsionpower to be split between hulls, thus reducing the limitation ofmaximum power installed in one narrow hull. With distributed propulsion the flexibility for transit and loitering operations is added and maneuvering efficiency increases.

4


CCDOTT High Speed Trimaran Technology and Concept Development Program

Very High Speed Sealift Trimaran (VHSST) Concept Design. Concept Evaluation; Trimaran Hull Forms Development & Model Testing

CCDOTT Program FY 99 – 01 (CY 00-02)DASH 70-knot Slender & Small Waterplane Trimaran (SWAT).Design Parametric Studies; Propulsion & Interaction Analysis; Hull Forms & Model Testing

ONR R&D Project FY 00-01 (CY 01-02)Dual Cruise & Sealift Large Trimaran Ship. Concept Evaluation

CCDOTT Program FY 02 (CY 03-04)Dual Short Sea Shipping Trailership Concept Design for USA SuperRoutes Commercial Alliance. Short Sea Shipping & Theater Support Vessel Requirements; Concept Design; Cost Estimate

CCDOTT Program FY 02 (CY 03-04)Heavy Air Lift Support Ship (HALSS). Heavy Air Lift Support Ship (HALSS). Sealift/Seabasing Mission Analysis; Hull Forms Development; Interference & Propulsion Study; Model Tests; Seakeeping Analysis; Buildability & Cost estimateCCDOTT Program FY 04-06 (CY 05-07)

5


HALSS Design Approach

Ensure wind speed over the deck: Transit and maneuver at speed 35 knotsUse Trimaran Configuration for large Flight Deck

Operations Area and for split of Propulsion Systems between hullsMaximize Seakeeping & Minimize Sea MotionsUtilize proven current commercial Machinery

Propulsion Technologies Maximize range: Use fuel most efficient Diesel

EnginesAffordable: Build to commercial standards using

commercial business practicesBuild and maintain in existing US facilities

6


0

5

10

15

20

25

30

35

40

0 500 1,000 1,500 2,000 2,500 3,000

Win

d O

ver D

eck

(KTA

S)

Modified Container

Ship

MOB

C-130 to scale

VLCC Tanker (Single Hull)

Required Deck Length (ft)

HALSSHALSS

Modified Super Tanker

Requirement

Capability

In 1963 launching and landing of C-130 was successfully tested onboard the USS FORRESTAL.

More wind speed over deck –less required length of runway.

7


HALSS HALSS Support of the Sea BasingSupport of the Sea BasingHALSS helps Early Insertion & Logistic Support:Deploys at High Speed (35 Knots) to move MEB Rotary Wing, military loads for Force Employment, PAX/Troops & airplanes fuel from CONUS directly to sea baseOperate fixed wing aircraft between advanced base and the sea baseHALSS helps Force Deployment:Operate fixed wing aircraft for theater operationsArrange and Configure military loads in preparation for early entry to the Theater operations

8


HALLS Mission Flexibility and Potential As Afloat Forward Staging Base

HALSS is a flexible platform and can support vertical maneuver from a sea based platform

Phased approach: HALSS can be considered as "bridge" platform with near- and far-term objectives.

In Near-term - support C-130J operations, which together with existing helosprovide vertical maneuver with light forces to a depth of 300 nautical miles, utilizing a air drop capability, as required.

In Far-term the same ship platform (with flight deck under hot exhaust shield requirements) would support HLVTOL capability to provide complimentary effects to Ship To Objective Maneuver (STOM) capabilities.

Maersk Post Panamax Conversion HALSS

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Flight Deck Length 1,100 FT Flight Deck Width / Docking Hull Beam 274 FT / 180 FTDraft 37.9 FTDepth 100 FTFull Displacement 65,000 MTPayload:

Combat forces sustainment 8,900 STAircraft Fuel Supply 2,650 ST

Fixed Wing Aircraft Six C-130JStowage Factor

Main (Flight) Deck 185,900 SQFTII Cargo Deck 141,000 SQFTIII (Crossover) & IV Decks 51,100 SQFT

HALSS Stowage Factor 46.7 SQFT/MT

Unrefueled Range of Sea Voyage - CONUS to Advanced Base or to JOA10,000 NM at 35 knots>15,000 NM at 25 knots

Followed by 10 days endurance in JOA

HALSS Principal CharacteristicsHALSS Principal Characteristics

10


HALSS Early Insertion – C-130 J OPS

Flight deck configuration assures aircraft launch and recovery into the wind enabling maximum takeoff and landing weight under most conditions.Sponson deck is removable to reduce beam to facilitate construction and dry-docking.

11


Baseline Machinery & Propulsion TechnologyDiesel – Diesel / Electric @ Propeller Option

MAN or Sulzer low-speedRTA and RT-flex engine 69 MW.

Wärtsilä Medium- Speed Diesel

36 MW HTS Superconducting AC

Motor OR 500 RPMconventional motorw/ reduction gear

2 x MAN or Sulzer RTA 96 (102 RPM) @ 2 x Lips FP Propellers

2 Electric Motors powered by 4 x Wartsila 16V46 @ 2 x Lips CP Propeller

HALSS Center Hull:

Side Hulls:

Large and most powerful propellers – Propeller diameter 9.10 m; 6 blades,total weight 102 mt

World’s LargestControllable PitchPropeller 44 MW

HALSS Propellers:Center hull FPP ~ 68.6 MW - 8 mSide hull CPP ~ 31 MW - 4.8 m

12


Technology Propulsion Options for HALSS Concept

Speed

Knots

Effective Horse Power

Shaft HP (US)

Shaft Power (MW)

With 10% Sea Margin RPM

10 3,239 4,728 3.5 3.9 3015 11,240 16,408 12.2 13.5 4520 25,667 37,470 28 31 5925 48,859 71,327 53 59 7430 94,867 138,491 103 114 8935 148,766 217,177 162 178 104

Propulsive Coefficient: 0.685

Predicted Power Requirements

Center Hull Alternative Propulsion Options: FPP – A - baselineSSPA Contra Rotating Units - BABB Pod for 150MW Sealift Concept under

evaluation in NSWCCD - C Preswirl Vanes – D

Side Hull Options:FPP/CPP – E - baselineAWJ - FPumpJet - G

Allows to increase

propulsion efficiency

for 8%

B C

D

GF/G

13


DieselDiesel--Propeller Section at MAN Diesel EnginesPropeller Section at MAN Diesel Engines

Twin MAN engines directly connected to 102 RPM FPP have arrangement and overall size advantages in comparison with baseline Sulzer engine. Both enginesare commercially available and provide the best combination for the power.Additional power for boost and for maneuvering is provided by medium speed diesel engines driving 514 RPM generators in the center hull, poweringelectric motors in the side hulls with FPP, CPP or Waterjet propulsors.

10

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HALSS Operational Fuel Consumption &

Cargo Weights Available

Vs. Range & Transit Speed

4 ,000

9 ,000

14 ,000

19 ,000

5,000 7 ,000 9 ,000 11 ,000 13 ,000 15 ,000

R a n g e , N M

F ue l w e igh t a t 3 5 k nF ue l w e igh t a t 3 0 k nF ue l w e igh t a t 2 4 k nC a rgo P a y loa d a t 35 k nC a rgo P a y loa d a t 30 k nC a rgo P a y loa d a t 24 k n

HALSS Operational Efficiency

Speed kts Power MWProvided

byFuel Rate g/kW-hr

Fuel, t (10,000 NM)

Days per 10,000 NM

10 5 D/G 210 1,129 41.7

20 44 14RTA96 175 3,864 20.8

25 91 14RTA96 175 6,378 16.7

30 146 14RTA96 175 8,509 13.9

35 206 All 187 10,993 11.9

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HALSS Operational Modeling and Parametric Studies

The Lockheed Martin 6 Degree of Freedom (6-DOF) model with HALSS Sea Motion Data is used for the analysis of various operational constrains:

Payload/radius sensitivities for the C-130J aircraft operating in the HALSS concept ship.

Parametrically vary the deck length and wind over deck

Target length is less than 1,000 ft

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HALSS Buildability Study FindingsComprehensive ship construction analysis done for both assembly on land and in the water. Construction of center and one connected side hull in drydocks with joining of the other side hull in the water after launching using buoyancy bargesHALSS three hull configuration is well suited to a modern Virtual Shipbuilding approach

Two Hulls in Notional US Dock

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An Affordable HALSS Built in the USA to Commercial Standards

HALSS Fits in Sparrows Point Dock(Dock currently in operation)

Combatant ship construction yards are not affordable

Large Commercial Ship and Naval Auxiliary yards are candidate companies

Mid-tier yards using Virtual Shipbuilding approaches are candidates

Starting with a quality contract design and properly planned and managed, a Virtual Shipbuilding approach can reduce design and construction costs by 20%

One piece construction at Sparrows Point, Baltimore in the old BethShip graving dock using extensive outsourcing of preoutfitted hull blocks

and float out using buoyancy barges

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HALSS Technology Elements

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0.4

0.65

0.9

1.15

1.4

0 2 4 6 8 10 12

35 knots 42 knots 49 knots 60 knots

VHSST-50 Hull Forms Development and Trimaran Resistance Interference Study

Model 5569 Testing Data

Fwd position: Calm Seas and SS7

Aft position: Calm seas and SS7

Stagger

Resistance ratio to Resistance in Aft position

At 50kn Only 15% Increase of Resistance at SS7

Optimum Stagger Depends on Speed

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Slender & SWAT Hull Forms Development CCDOTT & ONR – DASH Projects (2001)

LWL: 19.65 ftLOA: 19.68 ft

12"0 1 2 43 5 6 7 8 9 1110 12

PROFILE

171615 16.515.514.51413 18.517.5 18 19.519

Scale 1:50

LOA: LWL: Beam (cenBeam (totaBWL (centeDepth: Draft: Displ: LCB (fwd oWet Surf.:

Centroid:

DASH

18.50 112"

2 43 5 6 7 8

WATERLINES

109 11 12 13 14.514 1615 15.5 1716.5 17.5 18 19.519

TOW POINT

CENTROID

6"12" 9" 3"

AP

12"

9"

6"4.5"

1.5"3"

12

9"

6"

1112"

3"

BASELINE

1/2 BWL: 8.52"1/2 B: 8.68"

3"

SECTIONSSCALE 2:1

LC 1.5" 4.5" 6"

19

01

23

54

6

7.5"1.5"7.5" 4.5"6" 3"

4.5"

78

9-10

1817

1615

14 13 10

3"4.5"

6"

7.5"

1.5"3"4.5"6"

7.5"

299.86 m299.35 m

61.46 m21.63 m16.00 m5.75 m

18,548.99 mT6,202.78 sq.m.

LOA: LWL: Beam (total): BWL (center): Depth: Draft: Displ: Wet Surf.:

DASH

11.40Slenderness

Slender Center Hull

Scale 1:50

LO A: LW L: Beam (center):Beam (tota l): BW L (center): D epth: D raft: D ispl: LCB (fwd of AP): W et Surf.:

Centro id:

190185

1661420

817,971.

795,245.04

x = 8y = 0z = 2

DASH - SW AT Version

12"0 1 2 3 4 5 6 7 8 8.5 9 9.5 10 1110.5 11.5 12

012"

1 2 3 4 5 6 7 8 8.5 9 9.5 10 10.5 11 11.5 12

3"

6" 6.70"9"

12"

15" 15.75"

01

23

54

12

11109

78

3"

6"6 .70"

9"

12"

15"15.75"

C 1.5" 3" 4.5"LBASELINE6"1.5"6" 4 .5" 3"

1.5"

3"4.5"

6"6"

4.5"

3"

1.5"

LOA: 12.47 ftLW L: 12.15 ft

1/2 BW L: 5.58"1 /2 B : 6.66"

3"9"

6"12"15"15.75"

6.7" - DW L

SECTIO NSSCALE 2:1

PRO FILE

W ATERLINES

66

1.5"3"

6"4.5"

AP

TO W POINTCENT RO ID

LOA: LWL: Beam (total): BWL (center): Depth: Draft: Displ: Wet Surf.:

DASH - SWAT Gondola190.00 m185.24 m61.46 m14.20 m20.00 m8.50 m

17,971.93 mT5,245.04 sq.m.

Slenderness 7.13

SWAT Center Hull

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Slender & SWAT Resistance & Seakeeping Model Tests in DTMB (2001)

Slender DASH Trimaran Model 5597 Ship Resistance Components

0

500000

1000000

1500000

2000000

2500000

3000000

3500000

0 10 20 30 40 50 60 70 80Speed, knots

Res

ista

nce,

lb

Rts

Rfs

Rrs

Model Resistance in Head Seas

0

5

10

15

20

25

30

35

40

45

50

0 5 10 15 20 25 30 35 40Ship Scale Significant Wave Height, ft

Mod

el R

esis

tanc

e, lb

s

SWAT 70 knotsSlender 70 knotsSWAT 50 knotsSlender 50 knotsSWAT 30 knotsSlender 30 knots

Both Slender and SWAT Trimarans at Sea States 0, 5, 7 showed remarkably small increase in resistance: low levels of pitch , reduced

drag, slamming, green water on deck

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HALSS Hull Forms DevelopmentHigh Speed Trimaran technology development & hull forms optimization experience based on results of CCDOTT

& ONR 98-04 projects:

BL

CL

B1B2B3B4 B1 B2 B3 B4

WL 3300

WL 6600

WL 9900

WL 13200

WL 16500

WL 19800

WL 23100

UPPER DECK 26400 ABL

DWL 10500 ABL

16

15.5

151413

12

12

11

10

9

TRAN SOM TRANSOM

1

2

3

5

8 6

7

4

WET DECK 18000 ABL

98.5

8

76

5

21

3

4

CL SHIPSIDE HULL CLSIDE HULL

25250

13

Scale 1:50

LOA: LWL: Beam (center):Beam (total): BWL (center): Depth: Draft: Displ: LCB (fwd of AP): Wet Surf.:

Centroid:

190185

16611420

817,971.9

795,245.04

x = 81y = 0z = 2

DASH - SWAT Version

12"0 1 2 3 4 5 6 7 8 8.5 9 9.5 10 1110.5 11.5 12

012"

1 2 3 4 5 6 7 8 8.5 9 9.5 10 10.5 11 11.5 12

3"

6" 6.70"

9"

12"

15" 15.75"

01

23

54

12

11109

78

3"

6"6.70"

9"

12"

15"15.75"

C 1.5" 3" 4.5"LBASELINE6"1.5"6" 4.5" 3"

1.5"

3"4.5"

6"6"

4.5"3"

1.5"

LOA: 12.47 ftLWL: 12.15 ft

1/2 BWL: 5.58"1/2 B: 6.66"

3"9"

6"12"15"15.75"

6.7" - DWL

SECTIONSSCALE 2:1

PROFILE

WATERLINES

66

1.5"3"

6"4.5"

AP

TOW POINTCENTROID

Scale 1:50

LOA: LWL: Beam (center):Beam (total): BWL (center): Depth: Draft: Displ: LCB (fwd of AP): Wet Surf.:

Centroid:

190185

16611420

817,971.9

795,245.04

x = 81y = 0z = 2

DASH - SWAT Version

12"0 1 2 3 4 5 6 7 8 8.5 9 9.5 10 1110.5 11.5 12

012"

1 2 3 4 5 6 7 8 8.5 9 9.5 10 10.5 11 11.5 12

3"

6" 6.70"

9"

12"

15" 15.75"

01

23

54

12

11109

78

3"

6"6.70"

9"

12"

15"15.75"

C 1.5" 3" 4.5"LBASELINE6"1.5"6" 4.5" 3"

1.5"

3"4.5"

6"6"

4.5"3"

1.5"

LOA: 12.47 ftLWL: 12.15 ft

1/2 BWL: 5.58"1/2 B: 6.66"

3"9"

6"12"15"15.75"

6.7" - DWL

SECTIONSSCALE 2:1

PROFILE

WATERLINES

66

1.5"3"

6"4.5"

AP

TOW POINTCENTROID

HALSS Multi Disciplinary Optimization:Wave & Viscous-Inviscid Interaction, Scaling factors,

Sea Motions & Wave Loads, Structural Integrity

High Speed Performance & Structural Requirements Compromise

Excellent Seakeeping & Structural Support

Enough Area/Volume for all of Propulsion Machinery Options

23


Various tradeoffs performed with variants of the hull forms for Center and Side hulls: different angles of skeg arrangement, angles of Waterline entrances, buttocks shape, etc.

The baseline hull forms were assessed with calculations of hydrostatics and MQLT. The variants of the hulls lines and Trimaran configuration were analyzed wih use of CFD FLUENT.

HALSS Hull Forms Development

Model A2-1

-0.2

-0.1

0

0.1

0.2

-250 -200 -150 -100 -50 0 50 100 150 200 250

Path Length from Station 10 (m)

P / P

d @

35

kts

Streamline 1 Aft

Streamline 1 Fwd

Streamline 2 Aft

Streamline 2 Fwd

Streamline 3 Aft

Streamline 3 Fwd

Streamline 4 Aft

Streamline 4 Fwd

Model A2

-0.1

0

0.1

0.2

-250 -200 -150 -100 -50 0 50 100 150 200 250

Path Length from CL (m)

P / P

d @

35

kts

Streamline 1 Aft

Streamline 1 Fwd

Streamline 2 Aft

Streamline 2 Fwd

Streamline 3 Aft

Streamline 3 Fwd

Streamline 4 Aft

Streamline 4 Fwd

HULSS Lines Design with FLUENTPressure distribution along the streamlines – reducing positive pressure gradients

InitialImproved

Streamlines along Center and Side hulls – final version with optimized skegs

AFT

StaggerMiddle

Stagger

CFD/FLUENT&MQL T optimized HALSS Center hull forms

(blue lines)

24


Flow Visualization at Three Staggers at 35 knots

25


HALSS Center Hull w/o Skegs Test Results and Comparison

Baseline HALSS Trimaran configuration, which was chosen by minimizingthe positive pressure gradients along the Center hull has demonstratedstrong favorable interference between the Center and Side hullsFor other staggers this phenomenon is negativeThe Center hull stern hull forms need further optimization to minimize skegs-hull interaction and improve propeller wake

0

50000

100000

150000

200000

250000

300000

350000

400000

450000

500000

10 15 20 25 30 35 40 45

EHP

, KW

Test 3_Center Hull with skegsCalcs_Center Hull without skegTest 1_Center Hull without skegsTest 5_Trimaran (baseline config

26


0

1

2

3

4

10 15 20 25 30 35 40 45

1000

CR

Test 1_Wave PiercingBulb BowTest 2_Stem Bow

0

50000

100000

150000

200000

250000

300000

10 15 20 25 30 35 40 45

EHP,

KW Test 1_Bulb Bow

Test 2_Stem Bow

Wave Piercing Bow Bulb vs. Stem Bow Test Results

Original Wave Piercing Bow Bulb allowedto achieve about

10% reduction of EHPVs. Stem Bow

27


HALSS Model Test Results and ConclusionsThe most efficient HALSS configuration appeared to be minimal spacing.

Middle longitudinal position of the side hulls selected by minimization of pressure gradients along center hull streamlines proved to be validated by model tests. At middle position an extremely favorable interference has been observed. With adequate CFD tools this finding can lead to the innovative, highly efficient concepts of HALSS-type new ships.

Wave Piercing Bow Bulb (WPPB) proved to be efficient for the HALSS-type hull forms.

Skeg-Stern center hull interference has been underestimated and led to development of one center plane skeg (instead of two side skegs) and shaft and strut propellers arrangement. New improvement requires testing and more computational analysis.

Test results proved potential of utilizing favorable Viscous-Inviscid interference phenomenon in designing Trimarans. It requires better physical understanding and Tools, applicable to implement this potential for powering efficiency. This area of investigations is highly recommended for future R&D plans.

28


WASIM Trimaran Prediction and Analysis ProcedureDisplacement, Velocities, Accelerations; Relative Motions for Slamming and Emergence; Hull Girder Loads and Local Pressures; Interaction between Main and Side Hulls.

Assessment Criteria: Naval Air Operations (NATO STANAG 4154, 1997) Transit (NATO Generic Frigate)

Results of HALSS Seakeeping Analysis:HALSS Provides Favorable Seakeeping Performance: meets vertical

motion criteria up to sea state 6; horizontal acceleration criteria up to sea state 7; no Slamming below Sea State 7, etc

High Speed Trimaran Seakeeping StudyHigh Speed Trimaran Seakeeping Study

29


Nonlinear Effects in HALSS Seakeeping Assessment

• Hull above waterline is ignored in linear theory (frequency- domain) calculations

• This precludes evaluation of cross-structure slamming (for example)

• WASIM can include structure above waterline in the time- domain analysis

Not “seen” in linear theory

WASIM:WASIM:

30


Output data and Criteria

• Motions• Accelerations at various

locations• Shear and bending

moment, 25m increments• Slamming of hulls and

cross-structure• Propeller emersion• Available with

additional/future analyses:– Motion sickness incidence– Motion induced

interruptions

Pitch Displacement 1.50 degRoll Displacement 4.00 degVertical Acceleration (Midship/Centerline) 1.962 m/s2Vertical Acceleration (Midship/Beam) 1.962 m/s2Vertical Acceleration (Bow/Centerline) 1.962 m/s2Vertical Acceleration (Stern/Centerline) 1.962 m/s2Transverse Acceleration (Midship/Centerline) 0.981 m/s2Transverse Acceleration (Midship/Beam) 0.981 m/s2Transverse Acceleration (Bow/Centerline) 0.981 m/s2Transverse Acceleration (Stern/Centerline) 0.981 m/s2Centerhull Bottom Slamming 20 per hourSidehull Bottom Slamming 20 per hourBridge Deck Slamming 20 per hourPropeller Immersion 90 per hourBending Moment (Midships) 2.84E+09 N-mShear Force (Quarter Forward) 1.00E+06 N

User-supplied criteria (example)

Also need Operational Profile (percentage of time at each speed and heading in each sea state)

31


Wind Speed – Vessel Speed Correlation

Wind Speed Over Deck for Flight Operations

0

10

20

30

40

50

60

0 1 2 3 4 5 6 7Sea State

Win

d Sp

eed

(Kno

Wind Speed

Minimum Required Speed Over Deck

Maximum Required Speed Over Deck

Wind Speed Minimum Vessel Speed

Maximum Vessel Speed

(Knots) (Knots) (Knots)0 0.0 35.0 40.01 3.0 32.0 37.02 8.5 26.5 31.53 13.5 21.5 26.54 19.0 16.0 21.05 24.5 10.5 15.5

5.5 30.0 5.0 10.06 37.5 -2.5 2.57 51.5 -16.5 -11.5

Head Sea Cases used for AnalysisInsufficient Forward Speed to Maintain Maneuverability

Sea State Using Wind Speed Associated with a Sea State defines the required vessel speed to maintain 35 knot apparent wind speed over deck

Wind - Sea State

Wind - Vessel

32


Stagger Influence 15 knots – Maximum Response from All Headings

Pitch Angle

0

0.5

1

1.5

2

2.5

SS4 SS5 SS6 SS7

Stagger = 0.00Stagger = 0.24Stagger = 0.40Stagger = 0.80

Roll Angle

0

1

2

3

4

5

6

7

8

9

10

SS4 SS5 SS6 SS7


Vertical Acceleration at Bow - Centerline

0

0.5

1

1.5

2

2.5

3

SS4 SS5 SS6 SS7


Vertical Acceleration at Stern - Centerline

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

SS4 SS5 SS6 SS7


33


Pitch Angle

0

0.5

1

1.5

2

2.5

SS4 SS5 SS6 SS7

Separation = 0.36Separation = 0.75Separation = 1.25

Roll Angle

0

1

2

3

4

5

6

7

8

9

SS4 SS5 SS6 SS7


Vertical Acceleration at Bow - Centerline

0

0.5

1

1.5

2

2.5

3

SS4 SS5 SS6 SS7


Vertical Acceleration at Stern - Centerline

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

SS4 SS5 SS6 SS7

Separation = 0.36Separation = 0.75

Separation = 1.25

Separation Influence 15 knots –

Maximum Response from All Headings

34


Air Craft Operation Criteria Assessment

Vertical Displacement at Stern

10.0

15.5

21.026.531.5

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 1 2 3 4 5 6 7Sea State

(Vessel Speed Shown in Labels)

Ver

t. D

ispl

acem

ent (

RMS ResponseDisplacement Limit

Pitch Motion

10.0

15.5

21.026.531.5

0

0.2

0.4

0.6

0.8

1

1.2

0 1 2 3 4 5 6 7Sea State


Pitc

h An

gle

(Deg

ree RMS Response

Pitch Limit

Vertical Velocity at Touchdown Point

10.0

15.5

21.026.531.5

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 1 2 3 4 5 6 7Sea State


Vert.

Vel

ocity

(m/

RMS ResponseVelocity Limit

Vertical Acceleration at Bridge

31.5 26.5 21.015.5 10.0

0

0.5

1

1.5

2

2.5

0 1 2 3 4 5 6 7Sea State


Vert.

Acc

eler

atio

n (m

/sRMS ResponseAcceleration Limit

35


0 . 0 00 . 0 8

0 . 1 60 .2 4

0 . 2 90 . 3 5

0 . 4 0

0 . 5 3

0 .6 7

0 . 8 0

0 . 3 60 . 4 9

0 . 6 20 .7 5

0 .9 21 . 0 8

1 .2 5

0

0 .5

1

1 .5

2

2 . 5

3

3 .5

4

0 .0 0

0 . 1 6

0 . 2 9

0 .4 0

0 .6 7

0 .3 60 . 4 9

0 . 6 20 . 7 5

0 . 9 21 . 0 8

1 .2 5

0

0 . 5

1

1 . 5

2

2 . 5

3

3 . 5

4

9 0 1 1 5 1 4 01 8 0 2 4 0

3 0 00

0 .2 5

0 . 5

0

0 .5

1

1 . 5

2

2 . 5

3

3 .5

4

9 0 1 1 51 4 0 1 8 0

2 4 0 3 0 00

0 .2 5

0 . 5

0

0 .5

1

1 . 5

2

2 . 5

3

3 .5

4

Sample HALSS (Extrapolated) Roll Motion Calculations

Stagger StaggerSpacing Spacing

Beam Seas Quartering Seas

SS5

15 knots

Length LengthStagger Stagger

Small Side Hulls – 2.3% Large Side Hulls – 7.5%

SS4

48.5 knots

36


Wave Elevation Interference vs. Trimaran Configuration

Effect of Stagger along the Length of the Center hull

Effect of Separation along the Center hull The wave elevation, while in phase, at staggers maximum Aft (Stagger 0) and Maximum Fwd (Stagger 0.8), which is created by speed of the Center and Side Hulls (Speed 35 knots) and incoming waves (head seas, SS5), increase amplitude along the whole length of the Center hull. This amplification of center hull waves leads to additional bending moment in the hull girder loads and a wave trough in way of the props, which also leads to the excessive amounts of prop emergences.

This is new and not well definedphenomenon.Potentially, can guide the choiceof Trimaran configurationMore studies are needed

37


SummarySummaryHALSS potentially offers unique military capabilities for CONUS to Sea base logistics and early entry operationsC-130J operations from HALSS are feasible R&D studies and engineering development conducted in CCDOTT multi year Program substantiate the feasibility of the design with current technology and reasonable risk. The CCDOTT HALSS program is correlated with Sealift R&D studiesThe current project demonstrated important technical findings, like potential of favorable wave interaction for trimaran ship and feasibility of commercial slow speed machinery for high speed sealift ships A new approach to acquisition, design and construction is proposed to end the cycle of ever increasing naval ship acquisition cost. This approach needs further detailing to ensure that Future HALSS-type ship is buildable in multiple, existing U.S. facilities

38


Back-Ups

Questions?

39


X/(L/2)

Y/(

L/2)

-1.0 -0.5 0.0 0.5 1.0

-0.6

-0.4

-0.2

0.060.050.040.030.020.010.00

-0.01-0.02-0.03-0.04

H ALSS Trimaran With The Side Hull M oved 0 m ForwardOf The M ain Hull Transom

Ship Speed = 3 8 Knots

Re sults From SW IFT

Z/(L/2)

Transverse Location = 23.66m Outboard

Stern Bow

X/(L/2)

Y/(

L/2)

-1.0 -0.5 0.0 0.5 1.0

-0.6

-0.4

-0.2

0.060.050.040.030.020.010.00

-0.01-0.02-0.03-0.04

H ALSS T rimaran With The Side H ull Moved 50m ForwardOf The M ain Hull Transom



Z/(L/2)


Stern Bow

X/(L/2)

Y/(

L/2)

-1.0 -0.5 0.0 0.5 1.0

-0.6

-0.4

-0.2

0.060.050.040.030.020.010.00

-0.01-0.02-0.03-0.04

H ALSS Trimaran W ith The Side H ull M oved 10 0m ForwardOf The M ain Hull Transom



Z/(L/2)


Stern Bow

HALSS Trimaran Free Surface Elevations From

SWIFT at 38 knots

Aft Position

Forward Position

Middle Position

40


High Speed Trimaran Resistance Estimate

0

5

10

15

20

25

30

2 3 4 5 6 7 8 9Vs (m/s)

10,0

00 C

r; 1

0,00

0 Cw

Calculated Cr Calculated Cw Experiment Cr

MQLT Validated by Model Tests

Quasi Linear Theory method was modified to consider viscous-inviscid calculation of form resistance and transom drag – MQLT.MQLT was validated with DTMB testing results and compared withSHIPFLOW CFD calculations.MQLT is used for HST hydrodynamic design and optimization.

0.0E+00

5.0E-04

1.0E-03

1.5E-03

2.0E-03

2.5E-03

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Froude NumberC

w

SHIPFLOW

MQLT

Resistance - SHIPFLOW and MQLT

large trimaran concepts and technology...

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