Overview of model testing facilities

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Types of facilities • Towing tanks – – – – –

Conventional High-speed Shallow water tanks Ice tanks Depressurised towing tanks, to test with cavitation

• Cavitation tunnels – With or without free water surface – With or without possibility to test an entire ship model

• Ocean Basins – Modelling of waves, wind and current – Variable water depth?

• Rotating arm basins • Wind tunnels 2

Towing tanks - Applications • • • •

Resistance and propulsion tests of ship models Open water testing of propellers and propulsion systems Seakeeping tests in head and following seas Maneuvering tests – Planar motion mechanism (PMM) – Small zig-zag tests

• Seakeeping and towing operations of offshore structures • Testing of various types of structures – – – –

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Towed arrays Deflectors for seismic surveys Torpedoes Hydrofoil systems

Towing tanks at Marine Technology Centre Model store Drawing office Reception Tank II Ship model manufacturing shop 6 Trimming tank 7 NC milling machine for model production 8 Instrumentation workshop

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5 3

9

8

6

7 13

2

10.5

28

10

13.5

5.6 10.0

1 11

9 Carpenter workshop 10 Propeller model

1 2 3 4 5

TANK I

manufacturing shop 11 Cavitation laboratory 12 Dock gate 13 Wave absorber, Tank I + III 14 Wavemaker, Tank III 15

and Tank I+III Wave absorber, Tank III

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15

1 39

85 260

Length: Width: Depth:

Tank I 175.0 m 10.5 m 5.6 m

Tank II 25.0 m 2.8 m 1.0 m

Tank III Tank I +III* 85.0 m 260.0 m 10.5 m 10.5 m 10.0 m 5.6/10.0 m

* Tank I and III can be used simultaneously and also as one long tank (Tank I +III) by removing the gate (12) and wave absorber (15).

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TANK III

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High-speed tanks • Carriage speeds up to 25.7 m/s • Usually smaller cross-sections than conventional tanks • Testing of: – Performance of high-speed vessels – Torpedoes (often in full scale) – Foil systems

• The Marine Technology Centre lacks really high speed capability – Maximum carriage speed is 10 m/s

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DTMB high speed carriage: - L/B/T=514/6.4/4.9 m - Max speed: 25.7 m/s

Shallow water tanks • To test ship performance in shallow water – – – –

Resistance Propulsion Maneuvering (PMM) Seakeeping

• Mainly used for testing crafts for inland waterways • Adjustable water depth (by draining water) • Facilities: – Duisburg, Germany – Marin, NL – … many more

• At the Marine Technology Centre we can use the ocean basin with adjustable bottom

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Ice tanks • • • • • •

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HSVA, Hamburg Aalto University (VTT), Finland Aker Arctic, Finland Memorial Univ. St. Johns, Canada St. Petersburg, Russia KAIST, Korea (recently established)

HSVA Large Ice Tank Large Ice Model Basin Length

78 m

Breadth

10 m

Depth

2.5 m

Ice Freezing Rate 2 mm/hour Towing Carriage Speed Range

1 mm/s ..3 m/s

Towing Capacity 5 tons

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Depressurised towing tank • CSSRC, China • Marin, Netherlands: – – – –

Dimensions: 240 x 18 x 8 m Carriage speed: up to 8 m/s Models: 2 – 12 m in length, Max prop. Diam. 0.4 m. Test to be performed • Cavitation observation and inception • Pressure fluctuation measurements • Radiated noise measurements

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Cavitation tunnels • Pressure can be reduced to obtain cavitation • Model is stationary – water is circulating • Types of tests – – – – –

Propeller cavitation Pressure fluctuation on hull from propeller cavitaiton Measurement of noise from cavitating propeller Performance of hydrofoils Performance tidal energy devices

• Options – Free water surface • Testing of waterjets, ventilation effects

– Testing of entire ship model 10

The large cavitation tunnel at the Marine Technology Centre 25123 CONTRACTION 3000

8000 TEST SECTION AIR RELEASE

7O CONE

2082 DIA. 1200

AIR RELEASE PIPE

TO AUXILIARY PIPE SYSTEM

Ø 3000

PROPELLER MOTOR 300HP/3000RPM

SLIP RINGS

1500

HATCHES

21 Ø

TO AUXILIARY PIPE SYSTEM

HATCHES

8O CONE

Ø 3000

Ø 2204

CONCRETE RED.GEAR 1000/200RPM

Ø 2400

DC GEN. 300HP/1000RPM

NOISE INSULATION

CONTROLLABLE PITCH IMPELLER

IMPELLER SYNC.MOTOR 1700HP/1000RPM

17100

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Height between center lines: 10.00 m Width between center lines: 22.22 m Contraction area ratio: 6.25 : 1

Diameter of working section: Length of working section:

1.20 m 2.08 m

13000

00

Ø 3000

10000

FIXED POINT

2 STEEL SUPPORT BEAMS

View of the test section of KTII

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SSPA cavitation tunnel

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HYCAT - HSVA •

Types of tests: – wake distribution measurements – cavitation inception tests, cavitation tests – pressure fluctuation measurements – thrust-, torque measurements – noise measurements of cavitating and non-cavitating propellers – noise source detection – measurement of rudder forces – flow visualization studies – influence of appendages on wake, cavitation and propulsion – influence of gas content of the water on cavitation, noise and pressure fluctuations – detection of cavitation erosion

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Ocean basins • Possibility to simulate complete ocean environment – – – –

Waves from different directions Short-crested waves Current Wind

• Beam almost same as length – Can test ships at various headings towards the waves

• Typical tests: – – – – 15

Testing of fixed and moored offshore structures Testing of marine operations Ship seakeeping tests Ship maneuvering tests

Ocean basin at Marine Technology Centre Double-flap wave maker Multi-flap wave maker

Double-flap wave maker

80 m

OCEAN BASIN

Cross-section of Ocean Basin

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Length: 80 m - Width: 50 m - Depth: 0-10 m

TOWING TANK

50 m

Multi-flap wave maker

Model tests in the ocean basin

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Other ocean basins • • • • • •

Marin OTRC, Texas Lab Oceano, Brazil CSSRC, China Shanghai Jiao-Tong University, China Several basins planned or under construction in China • A new hydrodynamic test centre is planned in Singapore • In addition, there are many ship seakeeping basins around, such as: – SSPA Sweden, QinetiQ (UK), DTMB (US), KRISO (Korea), … • 18

Seakeeping basins generally lack current capability, and has smaller water depth

Marin ocean basin: LxBxT=45x36x10.5 Pit: diam 5 m, depth 20 m Movable bottom Very good current capability

Rotating arm basin – CSSRC, China

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Rotating arm basins • • • •

Captive model ship maneuvering tests Testing of torpedoes and submarines Often capable of very high speed testing Locations: – CSSRC, China – DTMB, USA – QinetiQ, UK

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Wind tunnels • Applications: – – – –

Testing of aerodynamic forces Funnel smoke tests Flow visualization Basic flow research

• High Reynolds number can be obtained

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