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CAV Workshop May 5‐6, 2015 1
Flow‐Induced Noise Technical Group
Center for Acoustics and VibrationSpring WorkshopApril 26, 2017Presented by:
Michael L. Jonson
CAV Workshop May 5‐6, 2015 2
Overview
• The mission of the Flow‐Induced Noise Group of the Center for Acoustics and Vibration is the understanding and control of acoustic noise and structural vibration induced by fluid flow.
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CAV Workshop May 5‐6, 2015 3
Group Members• Ted Bagwell, ARL Computational Fluid Dynamics• Zach Berger, ARL Flow Measurements• *William Bonness, ARL TBL Noise• *Tim Brungart, ARL Flow Acoustics• Ken Brentner, Aersp. Computational Acoustics• Dean Capone, ARL TBL Noise• Norm Foster, ARL Computational Fluid Dynamics• *Mike Krane, ARL Biological Acoustics• Lyle Long, Aersp. Computational Acoustics• *Peter Lysak, ARL Flow Acoustics• Richard Marboe, ARL Flow Acoustics• *Dennis McLaughlin, Aersp. Jet Noise• Michael McPhail, ARL Flow Measurements• *Phil Morris, Aersp. Jet Noise• Jonathan Pitt, ARL Computational Fluid Dynamics• Steve Young, ARL Flow Acoustics• Frank Zajaczkowski, ARL Computational Fluid Dynamics
3*Presenting at FLINOVIA
CAV Workshop May 5‐6, 2015 4
Student Presentations
• Topical Research Area Presentations– Mrunali C. Botre,“Rotorcraft Noise Abatement Procedures Development”
– Scott Hromisin, “Extending On‐Demand Noise Reduction to Industry Scale‐Models for Tactical Aircraft”
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Rotorcraft Noise Abatement Procedures Development
ASCENT 38
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Mrunali C. Botre
Advisor : Dr. Kenneth BrentnerCo-PI’s : Dr. Joseph F. Horn(PSU)
Daniel Wachspress (CDI)
OUTLINE
Motivation Noise Prediction System Validation of Noise Prediction System
Bell 430 Flight test data – Flyover Case Noise Abatement Procedure Summary
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Motivation• Rotorcraft noise becoming an increasingly larger issue with general
public– HAI’s “Fly Neighborly Guide” helpful for community noise
• Since publication, new rotorcraft and operations have been developed– Need for more detailed data and information about noise produced from
the operation of rotorcraft– Need for detailed and specific noise abatement procedures
• This project is to investigate noise abatement flight procedures of rotorcraft through modeling– Physics based modeling of noise leveraging previous research performed
for NASA and DoD– Comprehensive modeling of the many sources of rotor noise– Complete vehicle modeling during example flight procedures
• Flyover• Approach, departure• Turn maneuvers, etc.
Noise Prediction system
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Bell 430 Simulink Model
Other Modules
Control System
Equ of Motion
CHARM Module
PSU-WOPWOP
High-Fidelity Airloads
Swashplate Angles
AircraftState
MR and TR Forces and Moments fromCHARM
Flight dynamics (PSUHeloSim) trims the aircraft for the desired flight path CHARM (Continuum Dynamics Inc.) coupled with HeloSim generates loading,
blade surface, and geometry files PSU-WOPWOP predicts noise using Ffowcs Williams – Hawkings equation /
Farassat’s Formulation 1A.
Validation of Noise Prediction System
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Validation of Noise Prediction system(Bell 430 Run 126) – Ground Reflection included
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Simulation over estimates the OASPL but LAnoise levels are predicted quite well.
(LA)
Numerical Results compared with overhead microphone (MC11 - reference) SEL dB EPNL
dB
Predicted 97.26 99.11
Flight Test (PSU-WOPWOP processing)
97.47 99.99
Flight Configuration – Bell 430 Run 126
• Level flight
• Velocity : 94.7 knots
• GW : 8000 lbs
• Height : 190 feet
Comparison of the simulation with the flight test data : • Flight Test data shifted to
match the peaks• Helicopter is directly
overhead (190 ft) when time = 0 sec
Noise Abatement Procedure
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• Maximum BVI occurs around 6 deg descent angle
• Changing flight path angle results in lower noise level
• Advancing and retreating side BVI evident in A-weighted plots
• Forward hot spot has advancing side BVI directivity
• Rearward hot spot has retreating side BVI directivity
Noise abatement Procedure : Bell 430 descent case (no acceleration)
3deg descent 6deg descent 9deg descentFlight direction
Flight direction
LA
3deg descent 6deg descent 9deg descent
Goal: demonstrate acceleration changes the effective flight path angle and can be instead used to achieve lower noise level Flight Configuration :
• GW = 8170lbs
• V = 81 kts
Effective fpa = fpa - g*sin(fpa) [fpa=flight path angle) = 0.05 rad= 3.062 deg
Effective fpa = fpa - g*sin(fpa) = 0.156 rad= 8.94 deg
Flight direction
+0.05g 0.0g -0.05gacceleration deceleration • Acceleration and deceleration
result in an effective flight path angle change
• approximately 2-4 dB total OASPL dB noise reduction , which significantly smaller area of maximum noise
• approximately 6-8dBA LAnoise reduction
• Acceleration and deceleration results match different flight path angles very well
Noise abatement Procedure : Bell 430 descent case (6 deg. descent)
Flight direction
+0.05g 0.0g -0.05gacceleration deceleration
LA
Summary of Noise Abatement Procedure contd…
• Maximum BVI occurs at a specific flight path angle
• Accelerating the aircraft effectively varies the flight path angle from the maximum value and thus resulting in lower noise level.
• Though the flight test data shows maximum noise levels at 9 degree descent the abatement procedure is still valid• Changing the effective flight path angle results in less BVI noise
• BVI noise change due to change in wake geometry position and were the interaction occurs
• It doesn’t matter whether actual flight path and is changed or if effective flight path angle is changed
• Avoiding BVI noise on approach results in significant noise reduction
Summary Physics-based noise prediction system has been formed from previously existing tools Analysis of the impact of simple operational changes on noise has been performed:
descent angle, acceleration, etc. Validation with Bell 430 flight test very helpful
Future Plans Finish setup for other helicopters in flight test plan
Demonstrate PSU-WOPWOP capability to take loading data at multiple times and follow the desired flight path, to calculate transient flight noise levels
Focus on abatement procedure development
ACKNOWLEDGMENTSThis work was funded by the U. S. Federal Aviation Administration (FAA) Office of Environment and Energy as a part of ASCENT Project 38 under FAA Award Number: 13-C_AJFE-PSU-038. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the FAA or other ASCENT Sponsors.
Contributors
References[1] Watts, M. E.; Greenwood, E.; Smith, C. D.; Snider, R.; and Conner, D. A.; “Maneuver Acoustic Flight Test of the Bell 430 Helicopter Data Report,” NASA/TM–2014-218266, May 2014.[2] Li, Y.; Brentner, K.S.; Wachspress, D.A.; Horn, J.F.; Saetti, U.; and Sharma, K., “Tools for Development and Analysis of Rotorcraft Noise Abatement,” presented at AHS “Sustainability 2015,” Montreal, Sept 22-24, 2015.[3] U. Saetti, W. Villafana, K. S. Brentner, J. F. Horn, and Wachspress D. “Rotorcraft simulations with coupled flight dynamics, free wake, and acoustics.” presented at AHS 72nd Annual Forum Proceedings, West Palm Beach, FL, USA, May 2016.
• PI: Kenneth S. Brentner, The Pennsylvania State University (PSU)• Co-PIs: Daniel Wachspress (CDI); Joseph F. Horn (PSU)• Graduate Research Assistant: Mrunali Botre• Industrial Partners:
• Continuum Dynamics, Inc. (CDI)• Sikorsky Aircraft Corporation (SAC) – Cal Sargent• AHS International – Paul Schaaf
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Extending On-Demand Noise Reduction to Industry Scale-Models for Tactical Aircraft
Dennis K. McLaughlin, Philip J. Morris, and Scott HromisinThe Pennsylvania State University
&
Steven Martens and Erin L. LariviereGE Aviation, Cincinnati, OH
Presented at the Pennsylvania State University CAV Workshop Spring 2017
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Outline
Overview of Project Goals and Objectives Description of Concept Technical Approach Experimental Results Summary / Conclusions
Aircraft often operate with afterburner during launch and recovery
Close proximity personnel exposed to acoustic loads up to 150dB
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Overarching Goal & Major Objective
Overarching Goal: To further develop a very promising jet noise reduction method for tactical aircraft engine exhausts that has been recently demonstrated in Penn State’s Aeroacoustics Laboratory
Major Objective: To extend the successes of the fluidic insert noise reduction method from University to Industry model scale as a logical first step toward implementation on a full scale aircraft
Technical Approach: Conduct experiments and numerical simulations performed by Penn State University in collaboration with GE Aviation leading to experiments conducted in the Cell 41 GEA Laboratory
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Penn State Invention – “On Demand Noise Reduction” using Fluidic Inserts
Distributed blowing in the diverging portion of the supersonic exhaust nozzle using “compressor air” that is less than 5% of the core mass flow.
CAD Image Installed nozzle at PSU
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Noise Benefit of Fluidic InsertsFar field spectra and ∆OASPL’s ca. 2012 result
0.01 0.1 1 10
120
120
120
120
120
Strouhal Number
SPL
per u
nit S
t (dB
//(20P
a2 ))
TTR = 3.0
Mj = 1.36NPR = 3
20dB
= 60 , IPR = 3.0
Baseline3 Corr., Dinj = 0.06D , mratio = 3.8%
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40
60
90
120
MJ =1.36UJ≈700 m/sTTR = 3.0 (hot jet)MD =1.65
Polar angle measured relativeto downstream jet axis
Dexit = 0.885in
- Baseline Jet- Jet w/ Distributed Blowing
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Major Objective
• Major Objective: Extend the successes of the fluidic insert noise reduction method from University to Industry model scale as a logical first step toward implementation on a full scale aircraft.
Reynolds # ranges: PSU: 4.5 x 105 - 6.6 x 105
GEA: ~2.5 x 106
O(1in.)
5 inches
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Distributed Blowing Design from University to Industry Scale
Engineering Task:Adapt the Penn State Blowing System to
GE Scale &
Interface with Cell 41 facility
5 in
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Adaptation of the Penn State Blowing System to GE Scale
Injectors
High pressure air feed lines for injectors
Fully-Assembled CAD model
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Noise Reduction Distributed Blowing System at GE Aviation
Injectors plates used at GEA to generate fluidic corrugations (FC)
3, 4, & 5 injectors per FC distribute blowing into divergent section
RANS CFD performed at PSU to guide design of injectors and corrugations
Final nozzle assembly at GEA
5 injectors/FC 3 injectors/FC
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3
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5
1
2
3
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2
3
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Outline
Overview of ProjectGoals and ObjectivesDescription of ConceptPrevious ExperimentsTechnical ApproachExperimental ResultsSummary / Conclusions
Baseline jet
w/ Fluidic Corrugations
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Experimental Results
MD = 1.65, MJ = 1.36 - Over-expanded Jet
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80
90
100
110
120
130
10 100 1000 10000 100000
SPL
(dB
)
Frequency (Hz)
NPR 3.0 No Injection
NPR 3.0 IPR 3.0
6.5 dB
Jet Spectra in peak noise emission direction
Far Field Jet Noise Comparison Industry Scale Baseline vs Fluid Inserts Noise Reduction
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Far-Field Jet Noise OASPL Reduction
Far Field Jet Noise Comparison Industry Scale Baseline vs Fluid Inserts Noise Reduction
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Peak noise emission direction
MD = 1.65, MJ = 1.36 - Over-expanded JetJet Total Temperature Ratio (TTR), T0,J/Tamb = 3.0
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GE Results Fluidic InjectionScaled to Aircraft Size
Spectra scaled to full scale and extrapolated to 50 ft. sideline – Estimates Aircraft Carrier Environment
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Findings and Conclusions
Results of the experiments at GE Aviation demonstrated that significant levels of noise reduction were achieved with the industry size experiments
Scaling of noise benefits to full size aircraft at sideline distances found on aircraft carriers show dramatic noise benefits
2nd round experiments at GEA planned for June 2017
RANS CFD simulations assisted in design and will be continued and will be expanded to URANS and LES simulations
Plan to extend this method to university-scale models of multi-stream variable cycle engines
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Acknowledgements
This research was supported by ONR Contract # N00014-14-C-0157, with Dr. Joseph Doychak and Dr. Knox Millsaps serving as Program Officers.
The active participation of Chris Shoemaker, J.D. Miller, and the recently graduated Dr. Russell Powers in the planning and conducting of laboratory experiments is gratefully acknowledged.
Questions?
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Extras
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Prior Hard-Walled Corrugation Success
Penn State Fluidic Corrugation design loosely based on the Hard-Walled Corrugation concept (Seiner et al.)
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Steady RANS Simulations for Design Guidance
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Provide details of flow inside nozzle
Show the effects of: Number of injectors Location and Orientation
of injectors
Calculate “shape” of fluidic inserts
Insight into detailed insert flow structure
Total Temp. Contours
x Vorticity Contours
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Technical Approach Experiments at GE Aviation
• Technical Approach: Conduct experiments and numerical simulations performed by Penn State University in collaboration with GE Aviation leading to experiments conducted in the Cell 41 GEA Laboratory.
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Overview of Program
• This presentation summarizes a university-industry cooperative project to develop a new method of noise reduction applicable to US Navy Tactical Aircraft. The current most acute need is the reduction of the noise produced during take-off on aircraft carriers.
• Such noise reductions, if achievable at full scale, will have a significant impact on tactical aircraft noise and result in a decrease in noise induced hearing loss among Navy personnel.
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Penn State Jet Aeroacoustics Facility
- Designed for acoustic measurements in a university size anechoic chamber: dimensions: 5.02 6.04 2.80 m,
- Simulate hot jets by mixing helium with air.- Open jet wind tunnel - Forward flight simulation
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Activities and Accomplishments
• Distributed Blowing Design from University to Industry Scale:
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Engineering Task:
Adapt the Penn State Blowing System to GE
ScaleInjectors