Friction Resistance of Ship - NACE Internationalevents.nace.org/conferences/IMCS2008/papers/13.pdf · Chugoku Marine Paints, Nace Pusan Oct 2008 Friction Resistance of Ship

Chugoku Marine Paints, Chugoku Marine Paints, Nace Pusan Oct 2008Nace Pusan Oct 2008

Friction ResistanceFriction Resistanceof Shipof Ship


Drag for ShipsDrag for Ships

Air Drag Wave Drag Form Drag Frictional Drag

BC LNG Cont


FrictionFriction DragDragActive ModuleActive Module to friction dragto friction drag

Micro Micro bubblebubblePolymerPolymerRibletRibletElasticity modulusElasticity modulusContact angleContact angle

NNeegative Modulegative Module to friction dragto friction dragFoulingFoulingRRoughnessoughness


Roughness effectRoughness effectFouling Fouling Macro foulingMacro foulingSlimeSlime

Deterioration of surfaceDeterioration of surfaceRusting Rusting Peeling of paint filmPeeling of paint filmDamage of the surfaceDamage of the surface

Maintenance work at AfloatMaintenance work at Afloatunder water cleaningunder water cleaning

Maintenance work at DockMaintenance work at DockBlasting Blasting deduction of roughnessdeduction of roughnessCoating Coating coverage of roughness / propagation of roughnesscoverage of roughness / propagation of roughness

dust spray, contaminationdust spray, contamination


Hull surface conditionHull surface condition


Roughness increase by foulingRoughness increase by fouling


Proper conditionProper condition


Laminated layer Laminated layer of aged antifouling filmof aged antifouling film

may cause roughness by damage or peelingmay cause roughness by damage or peeling


Hull roughness by aging Hull roughness by aging CR system by BSRA gaugeCR system by BSRA gauge

CR AF50 ships

0

100

200

300

400

500

600

700

800

900

0 1 2 3 4 5 6 7 8 9 10 11 12

Ships ages

Hull

rough

ness

(μ

m)

Dry up F/B

Dry up V/B

Aft coat F/B

Aft Coat V/B

Average

Hull roughness increases by aging.

Huge roughness may be caused by peeling of the film.


Hull roughness by aging Hull roughness by aging Long life AF by BSRA gaugeLong life AF by BSRA gauge

Long life AF70 ships

0

100

200

300

400

500

600

700

800

900

0 1 2 3 4 5 6 7 8 9 10 11 12

Ships ages

Hul

l R

ough

ness

(μ

m)

Dry up F/B

Dry up V/B

Aft coat F/B

Aft Coat V/B

Averge

Hull roughness increases by aging.

Tar Epoxy Epoxy system is introduced, which may deduce the film damage and peeling off, and increment of roughness is much less than CR System


Hull roughness by aging Hull roughness by aging Self polishing AF by BSRA gaugeSelf polishing AF by BSRA gauge

SPC-AF40 ships

0

100

200

300

400

500

600

700

800

900

0 1 2 3 4 5 6 7 8 9 10 11 12

Ships ages

Hul

l ro

ughne

ss (

μm

)

Dry up 　F/B

Dry up 　V/B

Aft coat F/B

Aft coat V/B

Average

Hull roughness stabilized after 3 years.

Tar Epoxy Epoxy system is introduced, which may deduce the film damage and peeling off. Self polishing mechanism may cover increment the roughness by damage??


Active ModuleActive ModuleMicro Micro bubblebubbleBased on the test module, 10% reduction of friction resistance and 4% energy reduction is expected for the vessel 100m length /20m width /DLL 7m. Reduction of friction resistance and energy to form bubble is conflicting

* Study started at the Japan Ship Research Association Study started at the Japan Ship Research Association

PolymerPolymer （（TomTom’’ss effect)effect)As huge amount of polymer are required, it is not utilized for mAs huge amount of polymer are required, it is not utilized for marine arine

field.field.* found and developed by US Navy since 1940* found and developed by US Navy since 1940thth..


Active ModuleActive ModuleRiblet Riblet generate steady longitudinal vortex to control turbulent flogenerate steady longitudinal vortex to control turbulent flow.w.The surface will be covered with contamination and effectiveThe surface will be covered with contamination and effective life is life is limited.limited.

Surface profile like dimpleSurface profile like dimple

Elasticity modulusElasticity modulusEffect is not so clearly reported.Effect is not so clearly reported.

Contact angleContact angleEffect is not so clearly reportedEffect is not so clearly reported ..


Active ModuleActive ModulePolymer effectPolymer effect

the best elasticity modulusthe best elasticity modulusSurface chemical structure by hydrolysisSurface chemical structure by hydrolysiscontact anglecontact anglerelation between the contact angle relation between the contact angle (hydrophilic/hydrophobic mixture)(hydrophilic/hydrophobic mixture)

and friction resistanceand friction resistance

Surface of paint filmSurface of paint filmparticle distribution of pigmentsparticle distribution of pigmentsstructure of pigmentsstructure of pigmentsstructure of filmstructure of film


Measurement of friction resistanceMeasurement of friction resistance

Comparison of drag owning to surface Comparison of drag owning to surface roughnessroughness

Sand surfaceSand surface2 2 Hydrolysis type AF at smooth surfaceHydrolysis type AF at smooth surface1 1 Si elastomeric AF at smooth surfaceSi elastomeric AF at smooth surface


Velocity 0.5m/sec

Velocity 1.5m/sec

Drag Test


Panel 0.8m X 0.4m

Condition of 0.5m/sec

Measuring device

Drag test


3-Dimension Analysis of Paint Film Surface Sand Surface

Sand Surface

Roughness of BSRA : 169 μm


3-Dimension Analysis of Paint Film Surface Hydrolysis type AF -A

Silyl Acrylate with copper

Roughness of BSRA : 43 micron


Metallic Acrylate copper free


3-Dimension Analysis of Paint Film SurfaceHydrolysis type AF-B


3-Dimension Analysis of Paint Film SurfaceSi-A

Foul release coating



Friction resistance Friction resistance depend on the surface structure? depend on the surface structure?

Friction to flow rate

0.0000

0.0200

0.0400

0.0600

0.0800

0.1000

0.1200

0.1400

0 0.5 1 1.5 2 2.5

flow ate（m/sec）

Drag

(

kg

)

Hydrolisis-AF B

Hydrolisis-AF Ａ

Si-AFＢ

Sand Surface

AF-B and Si-B are almost same. AF-A is slightly large. The difference of water-repellent film and hydrophilic film was not acquired.

BSRAReduction of

Frictionμ 2m/sec

Sand Surface 170Hydrolysis-AF Ａ 43 29%Hydrolysis-AF B 39 35%Si-AF Ｂ 34 34%


Roughness of the sampleRoughness of the sample

CorrelationBSRA Ra Rz Pz Wz 0.5 1 1.5 1.8 2

BSRA 1Ra 0.891189 1Rz 0.998251 0.863803 1Pz 0.992941 0.936427 0.984192 1Wz 0.957783 0.978139 0.939117 0.98512 1

0.5 0.551133 0.862469 0.500983 0.645754 0.766435 11 0.897001 0.940786 0.872693 0.936774 0.971393 0.800296 1

1.5 0.875116 0.829556 0.859842 0.897466 0.908341 0.648331 0.966847 11.8 0.93458 0.819473 0.928981 0.936727 0.917168 0.548346 0.940224 0.981738 1

2 0.983098 0.876419 0.978425 0.982482 0.957349 0.572026 0.939426 0.946693 0.98367 1

BSRA Ra Rz Pz Wz43 4.2 13.1 24.8 12.5170 6.9 46.5 56.7 30.439 3.8 11.7 24.6 13.234 1.8 12.7 18.6 5.4


Friction to Surface Roughness

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0 50 100 150 200

0.5

1

1.5

1.8

2

Velocity 2.0m/s

Velocity 1.8m/s

Velocity 1.5m/s

Velocity 1.0m/s

Velocity 0.5m/s

Fr iction Resistance to Surface Roughness measured by BSRA guage

Fri

cti

on R

esis

tance (

Kg)

Surface Roughness (μm)

The linear relation between friction resistance and surface roughness indicates.


Friction Resistance Conclusion(1) Surface roughness is the dominant factor to deduce friction

resistance more than 30%.(2) BSRA roughness and Friction resistance shows good collation. (3) BSRA Gage may represent Roughness , Profile and Wave (Rz, Pz,

Wz). (4) Roughness of hull increases pursuant to age, but self-polishing

effect may control the roughness increase.(5) Paint surface property works deduction of friction resistance , and

the major cause might be surface roughness or profile. (6) The difference of water-repellent film and hydrophilic film was not

acquired.


Thank you Thank you for your kind for your kind attentionattention


Drag increase by slime attachment was reported by many references, as follows.

“Drag increase by bio-films. Understanding and prevention of drag increase due to marine fouling is as important as drag reduction.

Schultz & Swain (1999) compared turbulent boundary layers on natural marine bio-films and a smooth plate. The average increases in Cf for slime film with mean thickness of 160μm and 350μm were 33% and 68%, respectively.

Reference: Pro. Fred Stern et al.. The Resistance Committee Final Report and Recommendations to the 23rd ITTC, page 27.

Documents

Friction Resistance of Ship - NACE Internationalevents.nace.org/conferences/IMCS2008/papers/13.pdf · Chugoku Marine Paints, Nace Pusan Oct 2008 Friction Resistance of Ship