controlling machinery induced underwater noise (presentation)

8/11/2019 Controlling Machinery Induced Underwater Noise (Presentation)

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Controlling Machinery InducedControlling Machinery InducedUnderwater NoiseUnderwater Noise

Raymond Fischer, Noise Control Engineering, Inc.

NOAA Vessel Quieting Technology


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NCE/NOAA SymposiumNCE/NOAA Symposium

Approach ApproachHow much U/W noise reduction isHow much U/W noise reduction isrequired?required?Critical sourcesCritical sources MachineryMachinery Propulsor (covered by others)Propulsor (covered by others)Critical pathsCritical paths

Airborne and structureborne Airborne and structureborneNoise/Vibration control approachesNoise/Vibration control approachesUse NOAA Fisheries R/V as illustrationUse NOAA Fisheries R/V as illustration


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Range to achieve 120 dB LevelRange to achieve 120 dB Level

320021.51.8185Ship 2

1602.90.4172Ship 1

DREDGING

320021.51.8185

Conical Drilling

Unit

3204.60.6175Drill Ship

Drill ship, rigs, platforms

1000046.43190Large Tanker

126011.71181Supply Ship

1252.50.35171Tug & Barge

40.250.061565-m Zodiac

range, kmCylindricalspreading

range, km1.5 power spreading

range, kmSphericalspreading

Source Level,dB re 1 Pa

@1m


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Ocean AttenuationOcean Attenuation Attenuatio n at 10 km

(Spherical sp reading = 80 db)

0

10

20

30

40

50

60

70

80

90

100

10 20 40 80 160 315 630 1250 2500 5000 10000 20000 40000

Freq, Hz

A t t e n , d

B


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Cargo Ship Broad Band NoiseCargo Ship Broad Band NoiseRadiated NoiseCharacteristics of aModern Cargo Ship,

Arverson & Vendittis,JASA 107 (1), Jan.2000.

173 m Direct Drive


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Cargo Ship Broad Band NoiseCargo Ship Broad Band NoiseRadiated NoiseCharacteristics of aModern Cargo Ship,

Arverson & Vendittis,JASA 107 (1), Jan.2000.

173 m Direct Drive


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R a d i a t e d N o i s e - A l a s k a C r u i s e S h i ps

120

130

140

150

160

170

180

190

20 40 80 160 315 630 1250 2500 5000 10000 20000

TO B Fr e q ( H z )

Radiated NoiseRadiated Noise Cruise ShipCruise Ship


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Propeller Noise Sources

Cavitation noise& structural re-radiation

Machinery Noise Sources

Main propulsion system

Structural-borne path

Sea-connected system

Ship Noise Sources

Aux. Equipment

Air-borne path


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Various Drive Vibration LevelsVarious Drive Vibration Levels


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Best Acoustic DesignBest Acoustic DesignUse inherently quiet equipmentUse inherently quiet equipment Rotating rather than reciprocatingRotating rather than reciprocating

Use (dynamically) stiff foundationsUse (dynamically) stiff foundations

Place noisier equipment toward centerlinePlace noisier equipment toward centerlineUse double hulls or tanks outboard ofUse double hulls or tanks outboard ofEngine RoomEngine RoomDieselDiesel --Electric offers greatest opportunityElectric offers greatest opportunity Isolation mounts forIsolation mounts for gensetsgensets , quiet motors, quiet motors


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Vibration IsolatorsVibration IsolatorsBest shipboardBest shipboardnoise controlnoise control

element.element.Reduces SB path.Reduces SB path.Isolation ofIsolation ofPropulsion EnginesPropulsion Enginesrequires flexiblerequires flexiblecoupling and othercoupling and othercomponents.components.Use onlyUse onlyElastomeric MarineElastomeric Marine --Grade Mounts.Grade Mounts.RequiresRequiresdynamically stiffdynamically stifffoundations.foundations.

Does not eliminate low frequency noise!


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Two-stage Genset Isolation System for NOAA FRV

Upper Stage Mounts

Lower Stage Mounts


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Acoustic Insulation Acoustic Insulation

Reduces AB & SSBReduces AB & SSBTransmission.Transmission.

Typically insulationTypically insulation ssbase material is eitherbase material is eitherfiberglass or mineralfiberglass or mineralwool.wool.

High Transmission LossHigh Transmission Loss(or HTL) material has(or HTL) material hasmiddle layer of limp massmiddle layer of limp mass(usually leaded vinyl).(usually leaded vinyl).

Transmission Loss orTransmission Loss orSTC (SoundSTC (SoundTransmission Class)Transmission Class)defines performance.defines performance.


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Treatment EffectivenessTreatment Effectiveness

005500Raft mount equipmentRaft mount equipmentSteel framingSteel framing

101010101010Bow Thruster TreatmentsBow Thruster Treatments

55--101055--101000Damping; 2Damping; 2 --33 psf psf ; $8; $8 --$12/ft$12/ft 2255--10100055--1010 Acoustic Insulation Acoustic Insulation3 to 83 to 8 pcf pcf ; $1; $1 --$4/ft$4/ft22

001010 --

2020

00Vibration IsolationVibration Isolation passivepassive

$20$20 --$400/mt$400/mt

SSBSSBFSBFSB AB ABTreatmentTreatment

Values are approximate dB reduction of overall sound.

Quiet Vessel approximately 7% to 10% total cost of vessel. Quiet R/V15% to 20% cost of vessel.


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Follow ThroughFollow Through All the

treatmentsin the worldwill not

overcome apoorinspection/

QA andverificationprogram!


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Advanced Treatments Advanced Treatments Air layer (belt forward of engine room) Air layer (belt forward of engine room) Effective midEffective mid -- to highto high --frequency (10+ dB)frequency (10+ dB) Amplifies low freq ( Amplifies low freq ( --5 dB over 50 Hz bw)5 dB over 50 Hz bw) Holes can clog if not maintainedHoles can clog if not maintained

Hull coatingHull coating Effectiveness depends on materialEffectiveness depends on material

compliancecompliance and thickness (>10 dB)and thickness (>10 dB) Adherence and damage issues Adherence and damage issues


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Designer NOISEDesigner NOISEProgram forProgram forshipboard noiseshipboard noise

predictionpredictionCreated under USCreated under USNAVY SBIR ProjectNAVY SBIR Project

Part of FlagshipPart of FlagshipDesigner suite fromDesigner suite fromProteus EngineeringProteus Engineering

Ship specificShip specific Modeling, constants,Modeling, constants,

etc.etc.


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FRV-40 Noise Control Treatments.

Specially designed by U.S. Navy (NSWC)Specially designed by U.S. Navy (NSWC) Hull &

Hull &

Propeller Propeller

Applied to hull and bulkheads (16 tons)Applied to hull and bulkheads (16 tons) Damping Tiles Damping Tiles

Perimeter of Engine Room and other noisyPerimeter of Engine Room and other noisy

spacesspaces

Acoustic Acoustic

Insulation Insulation

Auxiliary Equipment & HVACAuxiliary Equipment & HVACSingle StageSingle Stage Isolation Isolation

Diesel Gens & Reciprocating EquipmentDiesel Gens & Reciprocating Equipment3512 system3512 system 18,113 kg; 3508 system18,113 kg; 3508 system 14,770 kg14,770 kg

Double Stage Double StageVibrationVibration

Isolation Isolation

Propulsion Motor Specially DesignedPropulsion Motor Specially Designed Low Noise Low Noise Equipment Equipment


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FRV Radiated NoiseFRV Radiated Noise 11 kts11 kts


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Prediction ToolsPrediction ToolsDIFFERENCE BETWEEN MEASURED A ND PREDICTED RAD IATED NOISE - A OE-6

-6

-4

-2

0

2

4

6

8

10

31.5 63 125 250 500 1000 2000 4000 8000

OB FREQ (Hz)

D E L T A

, d

B

754.5 LOA, 48,800 tons, twin screw


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Range to 120 dB LevelRange to 120 dB Level

1.1.03150FRV-40

3200->3222->11.8->.02185-20=165Ship 2

160->1.63->.10.4->.04172-20=152Ship 1

DREDGING3200->3222->11.8->.02185-20=165

Conical Drilling

Unit

320->3.24.6->.20.6->.06175-20=155Drill Ship

Drill ship, rigs,platforms

10000->10046->2.13.2->.32190-20=170Large Tanker

1260->12.612->.541.1->.11181-20=161Supply Ship

1302.50.4171Tug & Barge @

40.250.061565-m Zodiac

range, kmCylindricalspreading

range, km1.5 power spreading

range, kmSphericalspreading

Source Level,dB re 1 Pa

@1m


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SummarySummaryTechnology exists to evaluate and control shipTechnology exists to evaluate and control ship

noise & should be applied to vessels thatnoise & should be applied to vessels thatoperate in environmentally sensitive areasoperate in environmentally sensitive areasPrimary noise sources are the propulsion drivesPrimary noise sources are the propulsion drives

low frequencies and thelow frequencies and the propulsorspropulsors mid tomid to

high frequency (can trump oncehigh frequency (can trump once cavitatingcavitating ))Drives should be selected based on having lowDrives should be selected based on having lowvibration source levels and/or utilizing vibrationvibration source levels and/or utilizing vibrationisolation mountsisolation mountsNovel treatments show potential but needNovel treatments show potential but needdevelopmentdevelopment


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ReferencesReferencesOn active vibration isolation of floating raft system, J.On active vibration isolation of floating raft system, J. NiuNiu, K. Song, & C. Lim, J. of Sound and, K. Song, & C. Lim, J. of Sound andVibration, 285, 2005.Vibration, 285, 2005.

Active Vibration Isolation in Ships, M. Active Vibration Isolation in Ships, M. Winber Winber , S Johansson, L, S Johansson, L HakanssonHakansson & I.& I. ClaessonClaesson , Intl. J of, Intl. J of Ac. & Ac. & VibVib., 10 (4), 2005.., 10 (4), 2005. Active Control of Engine Induced Noise in a Naval Application, M Active Control of Engine Induced Noise in a Naval Application, M WinbergWinberg , S Johansson, T Lag,, S Johansson, T Lag,88 thth Intl Congress on Sound &Intl Congress on Sound & VibVib, Hong Kong, 2001., Hong Kong, 2001.Optimization of Vibration Isolation Mounts for Application to ShOptimization of Vibration Isolation Mounts for Application to Sh ipboard Diesel Engines, Aipboard Diesel Engines, AMuravyovMuravyov & S Hutton, Nat.& S Hutton, Nat. DefenceDefence R&D Branch, DREA CR/97/437, April 1997.R&D Branch, DREA CR/97/437, April 1997.

Effect of DragEffect of Drag --Reducing Air Lubrication on Underwater Noise Radiation from ShipReducing Air Lubrication on Underwater Noise Radiation from Ship Hulls, K.Hulls, K.MatveevMatveev , Trans. of the ASME, 137, Aug. 2005., Trans. of the ASME, 137, Aug. 2005.Simplified Structural Acoustic Characterization of External CompSimplified Structural Acoustic Characterization of External Comp liant Coatings on Submergedliant Coatings on SubmergedSurfaces, B. Sandman & J.Surfaces, B. Sandman & J. BoisvertBoisvert , NUWC Div. Newport Tech Digest, June 1995., NUWC Div. Newport Tech Digest, June 1995.Computational Evaluation of Damping and Decoupling Materials, PhComputational Evaluation of Damping and Decoupling Materials, Ph III, O.III, O. FoinFoin & A. Berry, Nat.& A. Berry, Nat.DefenceDefence R&D Branch, DREA CR/2000R&D Branch, DREA CR/2000 --016, Feb 2000.016, Feb 2000.

Introducing Decoupling Coatings in SEA Models, C.Introducing Decoupling Coatings in SEA Models, C. Audoly Audoly , Noise, Noise --Con 97, Penn State U., June,Con 97, Penn State U., June,1997.1997.


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controlling machinery induced underwater noise (presentation)

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