MILBURN - Noise and Vibration High Speed Patrol Craft
Guidelines for Noise and Vibration of High Speed Patrol Craft ASNE Multi-‐Agency Craft Conference USCG Yard, Curtis Bay MD, 9 June 2016
DARRELL MILBURN, CDR USCG (RET), INCE BD. CERT., PE [email protected]
978-‐741-‐1551 WWW.JANDAENTERPRISES.COM
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Guidelines for Noise and Vibration of High Speed Patrol Craft
Outline
• Noise Requirements • Fast Craft Noise Sources • Practical Tradeoffs – Space/Weight/Cost/Noise • Patrol Craft Vibration Criteria Questions & Discussion
2
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
High Speed Patrol Craft –
Why Noise Limits?
Exterior & Distant Noise • Mission Requirements: Acoustic Stealth • Airborne: Aural Detection • Underwater: hydrophone / acoustic mines
Onboard Noise • Mission Performance: – Voice Communications
• Hearing Conservation • Crew Endurance
3
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
High Speed Patrol Craft – Why Noise Limits? Exterior & Distant Noise: Acoustic Stealth Typical 20m/40 kts – wake & wash splash only at “R” receiver location main deck aft 90-‐95 dBA R
4
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
New Revision: MIL STD 1474-‐E • Approved for use for all DOD • Specific noise limits and requirements to designers and manufacturers • Noise limits shall not be exceeded if material is acceptable to the procuring activity • Approved for public release
5
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Airborne -‐ Aural Non-‐Detectibility Typical Limiting Noise Sources • Exhaust Noise • Spray, Propulsor and Wake Noise • Machinery Ventilation Noise • Tones / Hydraulic – Gear – Propeller -‐ gensets • Structureborne Noise Radiated from Exterior Surfaces • Flag flapping/halyards etc
Typical Criteria Limits
6
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Airborne -‐ Aural Non-‐Detectibility
SOUND PRESSURE
NOT TO EXCEED
FREQUENCY
7
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Airborne -‐ Aural Non-‐Detectibility Typical Limiting Noise Sources
• Exhaust Noise • Spray, Propulsor and Wake Noise • Machinery Ventilation Noise
8
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Airborne -‐ Aural Non-‐Detectibility Typical Limiting Noise Sources
• Exhaust Noise
• Spray, Propulsor and Wake Noise • Machinery Ventilation Noise
9
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Airborne -‐ Aural Non-‐Detectibility Typical Limiting Noise Sources
• Exhaust Noise • Spray, Propulsor and Wake Noise
• Machinery Ventilation Noise
10
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Airborne -‐ Aural Non-‐Detectibility Typical Limiting Noise Sources
• Decibel Combination of the three example sources • Dominated by exhaust, but • Splash and Vent must also be treated
11
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Airborne -‐ Aural Non-‐Detectibility Engine Exhaust Silencer Noise Reduction Requirement Example • If a lining providing 5 dB reduction added to vent duct and • Spray reduced to 1 dB less than Limit Curve 500-‐3150Hz, then • Noise Reduction target for exhaust is given at right
12
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
13
Voice Communications • Via Comms System: MIL-‐STD 1474E – New Revision – Speech Communication – Uses Modified Rhyme Test (ANSI S 3.2) – Predictors of Speech Intelligibility • Articulation Index • Speech Transmission Index • Speech Intelligibility Index
– Rhyme Test
• Face-‐to-‐Face: Compartment Categories – – – –
1474E Appendix F Naval Vessel Rules IMO or typical levels based on experience Benchmark sea trial for a baseline
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Frequency Range of Typical Voice Communications • Typical speech is mostly within the frequency range from 500-‐4000Hz • Figure shows third-‐ octave time average spectrum of male and female speakers reading this slide • Minimizing the masking noise in the frequency range for normal speaking improves voice communication intelligibility
14
Noise and Vibration High S peed Patrol Craft
Noise Limits by Compartment Category Quieter noise limits are related to locations requiring voice communications over medium and short distances. Octave band limits included with the Compartment A-‐weighted Noise Limits relate to constraints on the masking noise in speaking frequency range The criteria in MIL-‐STD 1474-‐E are applicable to SHIPS. Fast Patrol Craft have much more challenging noise levels so the cited criteria may be impractical on fast craft. 9 June 2016 ASNE MACC
Category Type A Control, Offices, Radio rooms B Berthing C Medical D Manned Aux, Workshops, Galley F Other occupied workshops & stations 15
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Hearing Conservation • Noise related hearing loss and tinnitus are the two most prevalent service-‐connected disabilities for VA new compensation recipients • HEARING PROECTION – Greater than 85 dBA (In excess of 84 dBA USN) “SINGLE” – “Double Protection” greater than 104 dBA or (160 dB(Peak))
• Sound Levels 85 dBA and greater require hearing conservation program USN / USCG
16
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Crew Annoyance / Crew Fatigue • Commonly incorporated by specification – quieter noise levels in Loiter/Patrol/Transit Modes – General guide – commercial vessels with crews living aboard: – complaints occurring for noise in excess of about 70dBA in berthing and lounges • Other Important Aspects (Often Overlooked) -‐ In-‐Harbor: Noise limits specific to HVAC – annoying fans -‐ Criteria for annoying tonal noise -‐ Tones from chillers, hydraulics, gears, etc are often annoying even if within A-‐weighted overall noise limit -‐ Design and treatments to limit these sources -‐ Acceptance criteria including limits for tonal noise
17
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
NOISE SOURCE LEVELS – typical 20m // 40 kts Without Acoustic Treatments
85-‐90 dBA
100 dBA 110 dBA
120 dBA
85 dBA 95 dBA
80 dBA 80-‐85 dBA
Waterspray – chine and hull, “firehose on a trash can “
90 -‐95 dBA
18
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Airborne // Structureborne • “Airborne” – Noise that you hear with your ears-‐ sound
pressure waves in the air. • “Structureborne” – Acoustic frequency range vibrations of a solid material. Transmits acoustic vibration energy through the structure • Surface vibrations from structureborne noise induce sound pressure waves at the receiver location. Interface of surface and air transfers structureborne to airborne sound energy
19
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
20
Optimizing Weights of Treatments 5mm AL + 6mm (9kg/m^2) DAMPING 22.5 kg/m^2
5mm AL 13.5 kg/m^2 SOURCE SPL 112dBA re 2e-‐5Pa
85 dBA + _85 dBA_ 88 dBA
SBN 85dBA re 5e-‐8 m/s 5mm AL + S-‐side (5kg/m^2) Barrier+Insul 19.5 kg/m^2
SPL 85(-‐4) dBA
SOURCE SPL 112dBA re 2e-‐5Pa
SBN 85dBA re 5e-‐8 m /s
5mm AL + R-‐side (2. 5kg/m^2) Barrier+Insul 16.7 kg/m^2
SPL 85(-‐24) dBA
SOURCE SPL 112dBA re 2e-‐5Pa
+ SBN 85(-‐0) dBA 85 dBA
SBN 85dBA re 5e-‐8 m /s
+ SBN 85(-‐8) dBA 83 dBA
SPL 85(-‐15) dBA
SOURCE SPL 112dBA re 2e-‐5Pa
+ SBN 85(-‐15) dBA 73 dBA
SBN 85dBA re 5e-‐8 m /s
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
21
Practical Noise Levels 100 dBA
110 dBA
80 90 85 dB dBA dBA A
120 dBA
95 dBA
No Treatments 80-‐85 dBA
95 dBA
Good Treatments
90 dBA 110 120 dBA dBA 95 dBA
80 dBA
75 dBA
85 dBA
85 dBA 110 120 dBA dBA
75 dBA
78 Less than 65 dB 75 dBA dBA A Less than 80dBA
Less than 75 dBA
Very Good Treatments
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Trade Offs – Sound Level Versus Complexity of Treatment for Fast Craft • • •
•
•
Fast craft: Performance is weight constrained Physics: Mass blocks noise Engineering: minimizes the required weight to attain given noise target Cost and complexity increase logarithmically to reduce noise while keeping performance Understanding noise sources and paths in a balanced approach is key
22
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Weird Noises
Unanticipated Noise Levels • Fast Boats – often flow related – Resonant effects – Vortex shedding/strouhal effects
Tonal Noise Complaints • Gears, Hydraulics, turbochargers & other compressors • Unacceptable Loudness / annoyance even when in limit
23
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
24
Vibration Guidelines TOUCH SCREENS/ TRACK BALLS / JOY STICKS/ THROTTLES FINE MOTOR SKILLS Subject to hand-‐arm vibrations
“WHOLE BODY” Vibrations – crew fatigue and annoyance Relationship to shock accelerations
MACHINERY VIBRATIONS – Machinery damage
Structural Damage FATIGUE CRACKING
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
To Avoid • For builders – non quantitative general statements – “Free from resonances” – “Free from excessive vibrations”
• For agencies – unenforceable / overly broad language, non-‐specific – Without quantitative criteria of requirements – Lacking attributes for engineering design
25
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Conclusion • Noise and vibration limits – For well being of crew – For performance of mission
• • • •
Practical trade-‐offs Importance of proper specification Faster / Smaller craft are more challenging Critical to engineer the treatments from concept design for best results and least cost / weight
26
DARRELL MILBURN, CDR USCG (RET), INCE BD. CERT., PE [email protected]
978-‐741-‐1551 WWW.JANDAENTERPRISES.COM
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Guidelines for Noise and Vibration of High Speed Patrol Craft
Outline
• Noise Requirements • Fast Craft Noise Sources • Practical Tradeoffs – Space/Weight/Cost/Noise • Patrol Craft Vibration Criteria Questions & Discussion
2
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
High Speed Patrol Craft –
Why Noise Limits?
Exterior & Distant Noise • Mission Requirements: Acoustic Stealth • Airborne: Aural Detection • Underwater: hydrophone / acoustic mines
Onboard Noise • Mission Performance: – Voice Communications
• Hearing Conservation • Crew Endurance
3
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
High Speed Patrol Craft – Why Noise Limits? Exterior & Distant Noise: Acoustic Stealth Typical 20m/40 kts – wake & wash splash only at “R” receiver location main deck aft 90-‐95 dBA R
4
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
New Revision: MIL STD 1474-‐E • Approved for use for all DOD • Specific noise limits and requirements to designers and manufacturers • Noise limits shall not be exceeded if material is acceptable to the procuring activity • Approved for public release
5
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Airborne -‐ Aural Non-‐Detectibility Typical Limiting Noise Sources • Exhaust Noise • Spray, Propulsor and Wake Noise • Machinery Ventilation Noise • Tones / Hydraulic – Gear – Propeller -‐ gensets • Structureborne Noise Radiated from Exterior Surfaces • Flag flapping/halyards etc
Typical Criteria Limits
6
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Airborne -‐ Aural Non-‐Detectibility
SOUND PRESSURE
NOT TO EXCEED
FREQUENCY
7
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Airborne -‐ Aural Non-‐Detectibility Typical Limiting Noise Sources
• Exhaust Noise • Spray, Propulsor and Wake Noise • Machinery Ventilation Noise
8
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Airborne -‐ Aural Non-‐Detectibility Typical Limiting Noise Sources
• Exhaust Noise
• Spray, Propulsor and Wake Noise • Machinery Ventilation Noise
9
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Airborne -‐ Aural Non-‐Detectibility Typical Limiting Noise Sources
• Exhaust Noise • Spray, Propulsor and Wake Noise
• Machinery Ventilation Noise
10
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Airborne -‐ Aural Non-‐Detectibility Typical Limiting Noise Sources
• Decibel Combination of the three example sources • Dominated by exhaust, but • Splash and Vent must also be treated
11
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Airborne -‐ Aural Non-‐Detectibility Engine Exhaust Silencer Noise Reduction Requirement Example • If a lining providing 5 dB reduction added to vent duct and • Spray reduced to 1 dB less than Limit Curve 500-‐3150Hz, then • Noise Reduction target for exhaust is given at right
12
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
13
Voice Communications • Via Comms System: MIL-‐STD 1474E – New Revision – Speech Communication – Uses Modified Rhyme Test (ANSI S 3.2) – Predictors of Speech Intelligibility • Articulation Index • Speech Transmission Index • Speech Intelligibility Index
– Rhyme Test
• Face-‐to-‐Face: Compartment Categories – – – –
1474E Appendix F Naval Vessel Rules IMO or typical levels based on experience Benchmark sea trial for a baseline
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Frequency Range of Typical Voice Communications • Typical speech is mostly within the frequency range from 500-‐4000Hz • Figure shows third-‐ octave time average spectrum of male and female speakers reading this slide • Minimizing the masking noise in the frequency range for normal speaking improves voice communication intelligibility
14
Noise and Vibration High S peed Patrol Craft
Noise Limits by Compartment Category Quieter noise limits are related to locations requiring voice communications over medium and short distances. Octave band limits included with the Compartment A-‐weighted Noise Limits relate to constraints on the masking noise in speaking frequency range The criteria in MIL-‐STD 1474-‐E are applicable to SHIPS. Fast Patrol Craft have much more challenging noise levels so the cited criteria may be impractical on fast craft. 9 June 2016 ASNE MACC
Category Type A Control, Offices, Radio rooms B Berthing C Medical D Manned Aux, Workshops, Galley F Other occupied workshops & stations 15
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Hearing Conservation • Noise related hearing loss and tinnitus are the two most prevalent service-‐connected disabilities for VA new compensation recipients • HEARING PROECTION – Greater than 85 dBA (In excess of 84 dBA USN) “SINGLE” – “Double Protection” greater than 104 dBA or (160 dB(Peak))
• Sound Levels 85 dBA and greater require hearing conservation program USN / USCG
16
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Crew Annoyance / Crew Fatigue • Commonly incorporated by specification – quieter noise levels in Loiter/Patrol/Transit Modes – General guide – commercial vessels with crews living aboard: – complaints occurring for noise in excess of about 70dBA in berthing and lounges • Other Important Aspects (Often Overlooked) -‐ In-‐Harbor: Noise limits specific to HVAC – annoying fans -‐ Criteria for annoying tonal noise -‐ Tones from chillers, hydraulics, gears, etc are often annoying even if within A-‐weighted overall noise limit -‐ Design and treatments to limit these sources -‐ Acceptance criteria including limits for tonal noise
17
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
NOISE SOURCE LEVELS – typical 20m // 40 kts Without Acoustic Treatments
85-‐90 dBA
100 dBA 110 dBA
120 dBA
85 dBA 95 dBA
80 dBA 80-‐85 dBA
Waterspray – chine and hull, “firehose on a trash can “
90 -‐95 dBA
18
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Airborne // Structureborne • “Airborne” – Noise that you hear with your ears-‐ sound
pressure waves in the air. • “Structureborne” – Acoustic frequency range vibrations of a solid material. Transmits acoustic vibration energy through the structure • Surface vibrations from structureborne noise induce sound pressure waves at the receiver location. Interface of surface and air transfers structureborne to airborne sound energy
19
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
20
Optimizing Weights of Treatments 5mm AL + 6mm (9kg/m^2) DAMPING 22.5 kg/m^2
5mm AL 13.5 kg/m^2 SOURCE SPL 112dBA re 2e-‐5Pa
85 dBA + _85 dBA_ 88 dBA
SBN 85dBA re 5e-‐8 m/s 5mm AL + S-‐side (5kg/m^2) Barrier+Insul 19.5 kg/m^2
SPL 85(-‐4) dBA
SOURCE SPL 112dBA re 2e-‐5Pa
SBN 85dBA re 5e-‐8 m /s
5mm AL + R-‐side (2. 5kg/m^2) Barrier+Insul 16.7 kg/m^2
SPL 85(-‐24) dBA
SOURCE SPL 112dBA re 2e-‐5Pa
+ SBN 85(-‐0) dBA 85 dBA
SBN 85dBA re 5e-‐8 m /s
+ SBN 85(-‐8) dBA 83 dBA
SPL 85(-‐15) dBA
SOURCE SPL 112dBA re 2e-‐5Pa
+ SBN 85(-‐15) dBA 73 dBA
SBN 85dBA re 5e-‐8 m /s
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
21
Practical Noise Levels 100 dBA
110 dBA
80 90 85 dB dBA dBA A
120 dBA
95 dBA
No Treatments 80-‐85 dBA
95 dBA
Good Treatments
90 dBA 110 120 dBA dBA 95 dBA
80 dBA
75 dBA
85 dBA
85 dBA 110 120 dBA dBA
75 dBA
78 Less than 65 dB 75 dBA dBA A Less than 80dBA
Less than 75 dBA
Very Good Treatments
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Trade Offs – Sound Level Versus Complexity of Treatment for Fast Craft • • •
•
•
Fast craft: Performance is weight constrained Physics: Mass blocks noise Engineering: minimizes the required weight to attain given noise target Cost and complexity increase logarithmically to reduce noise while keeping performance Understanding noise sources and paths in a balanced approach is key
22
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Weird Noises
Unanticipated Noise Levels • Fast Boats – often flow related – Resonant effects – Vortex shedding/strouhal effects
Tonal Noise Complaints • Gears, Hydraulics, turbochargers & other compressors • Unacceptable Loudness / annoyance even when in limit
23
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
24
Vibration Guidelines TOUCH SCREENS/ TRACK BALLS / JOY STICKS/ THROTTLES FINE MOTOR SKILLS Subject to hand-‐arm vibrations
“WHOLE BODY” Vibrations – crew fatigue and annoyance Relationship to shock accelerations
MACHINERY VIBRATIONS – Machinery damage
Structural Damage FATIGUE CRACKING
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
To Avoid • For builders – non quantitative general statements – “Free from resonances” – “Free from excessive vibrations”
• For agencies – unenforceable / overly broad language, non-‐specific – Without quantitative criteria of requirements – Lacking attributes for engineering design
25
9 June 2016 ASNE MACC
Noise and Vibration High S peed Patrol Craft
Conclusion • Noise and vibration limits – For well being of crew – For performance of mission
• • • •
Practical trade-‐offs Importance of proper specification Faster / Smaller craft are more challenging Critical to engineer the treatments from concept design for best results and least cost / weight
26
