nasa’s acoustic modeling and simulation tools for ... · nasa’s acoustic modeling and...

NASAs Acoustic Modeling and Simulation Tools for Perception-Influenced Design of

Urban eVTOL Systems

Dr. Stephen A. RizziSenior Researcher for Aeroacoustics

NASA Langley Research Center

Uber Elevate SummitApril 25-27, 2017

Dallas, TX

Outline

Perception-Influenced Design Auralization

Source-Path-Receiver Source Noise Description

Demonstrations Volocopter-like Multi-Rotor eVTOL, Tilt-Wing eVTOL Installation Effects Ambient Noise

Detection and Annoyance Predictions and Lab Studies

Uber Elevate Summit 2

Human response to aircraft community noise is a complex perception phenomenon that is a function of both acoustic and non-acoustic factors.

The aircraft vehicle design process requires a multi-disciplinary approach to achieve a set of design goals that typically include performance, safety, energy consumption, and noise. Noise goals usually specified in terms of certification

metrics, which may not fully reflect acoustic factors related to human response, nor are intended to reflect non-acoustic factors.

ICAO noise certification requirements are part of a balanced approach which strives to manage aircraft noise in the most cost-effective manner.

Background


Multiple FidelitySystem Noise

Prediction

MDAOEnvironment

AeroPerformance

Energy

Safety

.

.

.

Metrics-Driven Design Process for Noise

Source NoiseModels & Reduction

PropulsionAirframe

Aeroacoustics

Validated AeroacousticTools & Methods for

Low Noise

4

How well do certification metrics reflect human response to these systems?

0 4 8 12 16-0.03

-0.02

-0.01

0

0.01

0.02

0.03

Time (s)

Am

plitu

de


MDAOEnvironment

Perception-Influenced (Aircraft Vehicle) Design

Source NoiseModels & Reduction

PropulsionAirframe

Aeroacoustics

Multiple FidelitySystem Noise

PredictionAuralization

Human Response

and Metrics

Human PerceptionValidated Aeroacoustic

Tools & Methods forLow Noise

AeroPerformance

Energy

Safety

.

.

.

Perception-Influenced Design Design aircraft to achieve reduced community noise impact by simultaneously meeting noise certification and other design requirements, as well as other acoustic requirements which directly address human response.

6

Auralization offers the means to systematically assess benefits of future aircraft noise reduction technologies, configurations, and operations, through subjective testing.

Curved path

Synthesis here

Synthesis here

Path modeling includes:

1) Doppler shift/absolute delay2) Atmospheric absorption3) Spreading loss

Auralization Process: Source Path Receiver

(Not to scale)

4) Ground plane


The NASA Auralization Framework (NAF) performs these functions.

Source Noise Description

High Fidelity Analyses OVERFLOW, FUN3D CFD

8

Ground Testing Low Speed Aeroacoustic Wind Tunnel Anechoic chambers

Flight Testing Rotorcraft & UAVs

Low-Fidelity Codes for Propeller/Rotor Noise ANOPP Propeller Analysis System

Tonal loading and thickness noise components

Broadband Acoustic Rotor Code (BARC) Airfoil self-noise components


Source Noise Description

NASA Volocopter-like* eVTOL Multi-Rotor

* Based on information in The Volocopter flies! And is Ready to Take the Next Step to Urban Mobility, Florian Reuter, e-volo GmbH, NASA ODM Workshop, Hartford, CT, 29 Sept 2016.


Blade Design Used XROTORs minimum induced loss design method (18) 1.8m dia. 2-blade Clark Y airfoil

8.8 pitch at 75% r/R

Tip speed 160 m/s 1700 RPM, BPF 57 Hz Total thrust: 650 kg Power: 3.85 kW/rotor Figure of Merit: 0.69

Vehicle 2 passenger MTOM: 450 kg

NASA eVTOL Tilt-Wing Concept


Blade Design Based on multi-rotor design (8) 3m dia. 4-blade Clark Y airfoil

18.8 pitch at 75% r/R

Tip speed 140 m/s 891 RPM, BPF 59 Hz Total thrust: 1800 kg Power: 34.1 kW/rotor Figure of Merit: 0.73

Vehicle 4 passenger MTOM: 1250 kg 6 props on front wing 2 props on tail

Vertical Take-Off Scenario Multi-Rotor


Acoustic Modeling Zero angle of attack Tonal components only Rotors RPM - synchronized

30m

75m

Trajectory 10s hold at ground, 2.5 m/s rise to 75m Sideline observer at 30m

Time (s)

L A(d

B)

0 5 10 15 20 25 30 35 400

10

20

30

40

50

60

70

80

90

SynchR22


Acoustic Modeling Zero angle of attack Tonal components only Rotors RPM 2% variation

30m

75m


Time (s)

L A(d

B)

0 5 10 15 20 25 30 35 400

10

20

30

40

50

60

70

80

90

DFSynchR22


GROUND TESTING

Determine contributions of rotor and rotor-airframe interactions to radiated noise for simple vehicle configurations

Rotor and airframe support stands- Physically separate from one another- Able to vary rotor tip separation distance ()- Airframes of constant and variable cross-

section considered- ref 1

Results show- Harmonically rich for small rotor tip clearances () - Case of = 0.5 nearly identical to case of

isolated rotor

POC: Nik Zawodny Uber Elevate Summit 14

Investigation of Rotor-Airframe Interaction Noise Associated with Small-Scale Rotary-Wing Unmanned Aircraft Systems, Zawodny, Boyd, 73rd AHS Forum, Ft. Worth, TX, May 9-11, 2017.

SPL (

dB)

POC: Nik Zawodny

GROUND TESTING


SPL

(dB)


Acoustic Modeling Zero angle of attack Tonal components only Rotors RPM 2% variation Rotor Structure Interaction

30m

75m


Time (s)

L A(d

B)

0 5 10 15 20 25 30 35 400

10

20

30

40

50

60

70

80

90

DF+RSIDFSynchR22


10dBA lower than R22 (half as loud)


Acoustic Modeling Zero angle of attack Tonal components only Rotors RPM 2% variation Rotor Structure Interaction

30m

75m


Vertical Take-Off Scenario Tilt-Wing

Time (s)

L A(d

B)

0 5 10 15 20 25 30 35 400

10

20

30

40

50

60

70

80

90

DF+RSIDFSynchR22

10dBA lower than multi-rotor (half as loud)20dBA lower than R22 (quarter as loud)

Ambient Sound


US Bureau of Transportation Statistics

A-weighted 24-hour LAeq (dBA)You are here

55 dBA

But wish you were here38 dBA

Ambient Sound

Uber Elevate Summit 22Frequency (Hz)

SPL

(dB

)

200 400 600 800 10000

5

10

15

20

25

30

35

40

45

50City (55 dBA Leq)Park (38 dBA Leq)Pure Tone Threshold

The Full Monty - City Scenario


The Full Monty - Park Scenario


Detection ICHIN* Version 7 Predictions


Multi-Rotor Tilt-Wing

Normalized Range

Prob

abili

tyof

Det

e cti o

n(%

)

0 0.2 0.4 0.6 0.8 10

20

40

60

80

100City AmbientPark Ambient

0.2 0.45

Normalized Range

Prob

abili

tyof

Det

ectio

n(%

)

0 0.2 0.4 0.6 0.8 10

20

40

60

80

100

City AmbientPark Ambient

0.37 1.0

Must take into account the vehicle and its operating environment toeffectively reduce audibility.

In the city, detection is at the BPF for both vehicles. In the park, detection is at the 2nd and 3rd harmonics for both vehicles.

* I Can Hear it Now (Part of APET)

Emission Distance (normalized by sample x50)

Prob

abili

ty(#

with

in

/#su

rere

spon

ses)

00.511.520

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

| | 15| | 22.5| | 30

Detection Lab Studies

26

NASA Langley Exterior Effects Room

Normalized Emission Distance

Prob

abili

ty(#

Sure

s/#

Tota

lSur

es)

00.511.50

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Subject Dataxx50Probit Fit

Rotorcraft Fly-In Detection

Rotorcraft Fly-In Localization

A Laboratory Method for Assessing Audibility and Localization of Rotorcraft Fly-In Noise, Rizzi et al., 73rd AHS Forum, Ft. Worth, May 9-11, 2017.

Time-Varying Noise Metrics


Loudness Roughness

0 10 20 30 40

Time (s)

0

5

10

15

20

25

30

35

Loud

ness

(son

e)

Multi-Rotor: N5=26.59 sone

Tilt-Wing: N5=14.98 sone

0 10 20 30 40

Time (s)

0

0.5

1

1.5

Rou

ghne

ss (a

sper

)

Multi-Rotor: R5= 1.30 asper

Tilt-Wing: R5= 0.96 asper

0 10 20 30 40

Time (s)

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

Fluc

tuat

ion

Stre

ngth

(vac

il)

Multi-Rotor: FS5= 0.03 vacil

Tilt-Wing: FS5= 0.02 vacil

Fluctuation Strength

A-Weighted Level Sharpness Tonality

0 10 20 30 40

Time (s)

0

20

40

60

80

LA

S (d

B)

Multi-Rotor: LA S

5= 74 dB

Tilt-Wing: L A S5= 64 dB

0 10 20 30 40

Time (s)

0

0.1

0.2

0.3

0.4

0.5

0.6

Shar

pnes

s (a

cum

)

Multi-Rotor: S5= 0.42 acum

Tilt-Wing: S5= 0.41 acum

0 10 20 30 40

Time (s)

0

0.2

0.4

0.6

0.8

1

1.2

Tona

lity

(tu)

Multi-Rotor: T5= 0.95 tu

Tilt-Wing: T5= 1.03 tu

Zwicker & Fastl Psychoacoustic Annoyance


0 10 20 30 40

Time (s)

0

10

20

30

40

50Ps

ycho

acou

stic

Ann

oyan

ce

Multi-Rotor: PA5=37.88

Tilt-Wing: PA5=20.43

Annoyance Lab Studies

29

A Psychoacoustic Evaluation of Noise Signatures from Advanced Civil Transport Aircraft, Rizzi, Christian, 22nd AIAA/CEAS Aeroacoustics Conference, Lyon, France, May 31, 2016, AIAA-2016-2907.

Initial Investigation into the Psychoacoustic Properties of Small Unmanned Aerial Vehicle Noise, Christian, Cabell, AIAA Aviation 2017

LTA Ref

SA Ref T+W160

HWB301

Comparison of EPNL reduction

EPN

LR

educ

tion

(EPN

dB)

T+W

160-

GTF

-ITD

Appr

oach

T+W

160-

GTF

-ITD

Side

line

HW

B301

-GTF

-ITD

Appr

oach

HW

B301

-GTF

-ITD

Side

line

0

2.5

5

7.5

10

12.5

15System Noise PredictionWith Adjustment

SA LTA

Qui

eter

Perception-influenced design is made possible through the use of validated noise prediction models supporting auralization and models for human response (e.g., detection and annoyance).

NASA has unique capabilities in the areas of systems analysis, system noise prediction inclusive of important propulsion airframe aeroacoustics, auralization, and psychoacoustic testing. These capabilities were demonstrated on two relevant

urban eVTOL concepts. Come and see us at our interactive demo where you can

experience the eVTOL and other aircraft auralizations in an immersive environment.

Conclusions


Movies and sounds are available for download at:

http://stabserv.larc.nasa.gov/flyover/


ContributorsAric Aumann (SAIC) Auralization and interactive demoJon Levy, Eric Fay, Josh Sams (AMA Studios) 3D graphicsDan Palumbo (AMA) AuralizationMichael Patterson (NASA) Propeller/rotor designNoah Schiller (NASA) AuralizationCharlie Smith (AMA) Detection analysisNik Zawodny (NASA) Propulsion Airframe Aeroacoustics

Acknowledgments

This research was supported by the NASA Aeronautics Research MissionDirectorate (ARMD), Advanced Air Vehicles Program (AAVP), RevolutionaryVertical Lift Technology (RVLT) Project, and the Transformative AeronauticsConcept Program (TACP), Transformational Tools and Technologies (TTT) Project.


Thank You

1. Rizzi, S.A., Toward reduced aircraft community noise impact via a perception-influenced design approach (Keynote), InterNoise 2016, Hamburg, Germany, August 22-24, 2016.

2. Rafaelof, M., A model to gauge the annoyance due to arbitrary time-varying sound, Noise-Con 2016, Providence, RI, June 13-15, 2016.

3. Christian, A. and Lawrence, J., Initial development of a quadcopter simulation environment for auralization, 72nd AHS Forum, West Palm Beach, FL, May 17-19, 2016.

4. Rizzi, S.A. and Christian, A., "A psychoacoustic evaluation of noise signatures from advanced civil transport aircraft," 22nd AIAA/CEAS Aeroacoustics Conference, AIAA 2016-2907, Lyon, France, May 30 - June 1, 2016.

5. Rizzi, S.A., Burley, C.L., and Thomas, R.H., "Auralization of NASA N+2 aircraft concepts from system noise predictions," 22nd AIAA/CEAS Aeroacoustics Conference, AIAA 2016-2906, Lyon, France, May 30 - June 1, 2016.

6. Rizzi, S.A., Stephens, D.B., Berton, J.J., Van Zante, D.E., Wojno, J.P., and Goerig, T.W., "Auralization of flyover noise from open rotor engines using model scale test data," AIAA Journal of Aircraft, Vol. 53, No. 1, pp. 117-128, 2016.

7. Rizzi, S.A. and Christian, A., A method for simulation of rotorcraft fly-in noise for human response studies, InterNoise 2015, San Francisco, CA, August 9-12, 2015.

8. Christian, A., Boyd Jr., D.D., Zawodny, N.S., and Rizzi, S.A., Auralization of tonal rotor noise components of a quadcopter flyover, InterNoise 2015, San Francisco, CA, August 9-12, 2015.

Bibliography

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9. Aumann, A.R., Tuttle, B.C., Chapin, W.L., and Rizzi, S.A., The NASA Auralization Framework and Plugin Architecture, InterNoise 2015, San Francisco, CA, August 9-12, 2015.

10. Rizzi, S.A., Lopes, L.V., and Burley, C.L., NASA's aeroacoustic tools and methods for analysis of aircraft noise, AIAA SciTech 2015, Kissimmee, FL, January 5-9, 2015 (Abstract Only).

11. Rizzi, S.A., Palumbo, D.L., Hardwick, J.R., and Christian, A., Recent advances in aircraft source noise synthesis, 168th Meeting of the Acoustical Society of America, Indianapolis, IN, October 27-31, 2014.

12. Aumann, A.R., Chapin, W.L., and Rizzi, S.A., An open architecture for auralization of dynamic soundscapes, 168th Meeting of the Acoustical Society of America, Indianapolis, IN, October 27-31, 2014.

13. Tuttle, B.C., and Rizzi, S.A., Simulation of excess ground attenuation for aircraft flyover noise synthesis, 168th Meeting of the Acoustical Society of America, Indianapolis, IN, October 27-31, 2014.

14. Hardwick, J.R., Christian, A., and Rizzi, S.A., Evaluation of the perceptual fidelity of a novel rotorcraft noise synthesis technique, 168th Meeting of the Acoustical Society of America, Indianapolis, IN, October 27-31, 2014.

15. Rizzi, S.A., Aumann, A.R., Lopes, L.V., and Burley, C.L., Auralization of hybrid wing body aircraft flyover noise from system noise predictions, AIAA Journal of Aircraft, Vol. 51, No. 6, pp. 1914-1926, 2014.

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16. Arntzen, M., Rizzi, S.A., Visser, H.G., and Simons, D.G., A framework for simulation of aircraft flyover noise through a non-standard atmosphere, AIAA Journal of Aircraft, Vol. 51, No. 3, pp. 956-966, 2014.

17. Rizzi, S.A., Stephens, D.B., Berton, J.J., Van Zante, D.E., Wojno, J.P., and Goerig, T.W., Auralization of flyover noise from open rotor engines using model scale test data, 20th AIAA/CEAS Aeroacoustics Conference, AIAA-2014-2750, Atlanta, GA, June 16-20, 2014.

18. Palumbo, D.L., Nark, D.M., Burley, C.L., and Rizzi, S.A., Aural effects of distributed propulsion, 14th AIAA Aviation Technology, Integration, and Operations Conference, Atlanta, GA, June 16-20, 2014 (Abstract Only).

19. Rizzi, S.A., Lopes Jr, V., Burley, C.L., and Aumann, A.R., Auralization architectures for NASAs next generation aircraft noise prediction program, Noise-Con 2013, Denver, CO, August 26-28, 2013.

20. Okcu, S., Rathsam, J., and Rizzi, S.A., Psychoacoustic analysis of synthesized jet noise, Noise-Con 2013, Denver, CO, August 26-28, 2013.

21. Rizzi, S.A., An overview of virtual acoustic simulation of aircraft flyover noise (Invited Plenary), Structural Dynamics: Recent Advances, Proceedings of the 11th International Conference, Pisa, Italy, 2013.

22. Faller II, K.J., Rizzi, S.A., and Aumann, A.R., Acoustic performance of a real-time three-dimensional sound-reproduction system, NASA TM-2013-218004, June 2013.

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23. Rizzi, S.A., Aumann, A.R., Lopes, L.V., and Burley, C.L., Auralization of hybrid wing body aircraft flyover noise from system noise predictions, 51st AIAA Aerospace Sciences Meeting, AIAA-2013-0542, Grapevine, TX, 2013.

24. Okcu, S., Allen, M.P. and Rizzi, S.A., Psychoacoustic assessment of a new aircraft engine fan noise synthesis method, 164th Meeting of the Acoustical Society of America, Kansas City, MO, 2012.

25. Arntzen, M., Rizzi, S.A., Visser, H.G., and Simons, D.G., A framework for simulation of aircraft flyover noise through a non-standard atmosphere, 18th AIAA/CEAS Aeroacoustics Conference, AIAA-2012-2079, Colorado Springs, CO, 2012.

26. Allen, M.P., Rizzi, S.A., Burdisso, R., and Okcu, S., Analysis and synthesis of tonal aircraft noise sources, 18th AIAA/CEAS Aeroacoustics Conference, AIAA-2012-2078, Colorado Springs, CO, 2012.

27. Rizzi, S.A., Aumann, A.R., Allen, M.P., Burdisso, R., and Faller II, K.J., Simulation of rotary and fixed wing flyover noise for subjective assessments, (Invited), 161st Meeting of the Acoustical Society of America, Seattle, WA, May 23-27, 2011 (Abstract Only).

28. Faller II, K.J., Rizzi, S.A., and Aumann, A.R., Acoustic performance of an installed real-time three-dimensional audio system - Part II, 161st Meeting of the Acoustical Society of America, Seattle, WA, May 23-27, 2011 (Abstract Only).

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29. Faller II, K.J., Rizzi, S.A., Schiller, N., Cabell, R.H., Klos, J., Chapin, W.L., and Aumann, A.R., Acoustic performance of an installed real-time three-dimensional audio system, Proceedings of Meetings on Acoustics (POMA), Acoustical Society of America, Vol. 11, pp. 1-13, 2010.

30. Faller II, K.J., Rizzi, S.A., Schiller, N., Cabell, R.H., Klos, J., Chapin, W.L., and Surucu, F., Acoustic performance of an installed real-time three-dimensional audio system, 2ndPan-American/Iberian Meeting on Acoustics, 160th Meeting of the Acoustical Society of America, Cancun, Mexico, 2010 (Abstract Only).

31. Faller II, K.J., Rizzi, S.A., Klos, J., Chapin, W.L., Surucu, F., and Aumann, A.R., Acoustic calibration of the Exterior Effects Room at the NASA Langley Research Center, Proceedings of Meetings on Acoustics (POMA), Acoustical Society of America, Vol. 9, No. 015004, pp. 1-10, 2010.

32. Faller II, K.J., Rizzi, S.A., Klos, J., Chapin, W.L., Surucu, F., and Aumann, A.R., Acoustic calibration of the Exterior Effects Room at the NASA Langley Research Center, 159thMeeting of the Acoustical Society of America and Noise-Con 2010, Baltimore, MD, April 19-23, 2010 (Abstract Only).

33. Rizzi, S.A., Sullivan, B.M., and Aumann, A.R., Recent developments in aircraft flyover noise simulation at NASA Langley Research Center, NATO Research and Technology Agency AVT-158 Environmental Noise Issues Associated with Gas Turbine Powered Military Vehicles Specialists Meeting, NATO RTA Applied Vehicle Technology Panel, Paper 17, pp. 14, Montreal, Canada, 2008.

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34. Rizzi, S.A. and Sullivan, B.M., Synthesis of Virtual Environments for Aircraft Community Noise Impact Studies, Proceedings of the 11th AIAA/CEAS Aeroacoustics Conference, AIAA-2005-2983, Monterey, CA, May 2005.

35. Rizzi, S.A., Three-Dimensional Audio Client Library, NASA Tech Briefs, Vol. 29, No. 2, 2005, pp. 45.

36. Sullivan, B.M. and Rizzi, S.A., Further Developments in Aircraft Flyover Noise Synthesis and Propagation, 148th Meeting of the Acoustical Society of America, San Diego, CA, November 15-19, 2004 (Abstract Only).

37. Grosveld, F.W., Sullivan, B.M., and Rizzi, S.A., Temporal Characterization of Aircraft Noise Sources, Proceedings of the 42nd AIAA Aerospace Sciences Meeting, AIAA-2004-1029, Reno, NV, January 5-8, 2004.

38. Rizzi, S.A., Sullivan, B.M., and Cook, B.A., Signal Processing for Aircraft Noise (Invited), 146th Meeting of the Acoustical Society of America, Austin, TX, November 10-14, 2003 (Abstract Only).

39. Rizzi, S.A., Sullivan, B.M., and Sandridge, C.A., A Three-Dimensional Virtual Simulator for Aircraft Flyover Presentation, Proceedings of the 2003 International Conference on Auditory Display, Boston, MA, 2003.

40. Rizzi, S.A. and Sullivan, B.M., Prediction-Based Aircraft Flyover Noise Synthesis, 145thMeeting of the Acoustical Society of America, Nashville, TN, April 28 May 2, 2003 (Abstract Only).

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39

NASAs Acoustic Modeling and Simulation Tools for Perception-Influenced Design of Urban eVTOL SystemsOutlineBackgroundMetrics-Driven Design Process for NoiseHow well do certification metrics reflect human response to these systems?Perception-Influenced (Aircraft Vehicle) DesignAuralization Process: Source Path ReceiverSource Noise DescriptionSource Noise DescriptionNASA Volocopter-like* eVTOL Multi-RotorNASA eVTOL Tilt-Wing ConceptVertical Take-Off Scenario Multi-RotorSlide Number 13GROUND TESTINGGROUND TESTINGGROUND TESTINGGROUND TESTINGGROUND TESTINGSlide Number 19Slide Number 20Ambient SoundAmbient SoundThe Full Monty - City ScenarioThe Full Monty - Park ScenarioDetection ICHIN* Version 7 PredictionsDetection Lab StudiesTime-Varying Noise MetricsZwicker & Fastl Psychoacoustic AnnoyanceAnnoyance Lab StudiesConclusionsSlide Number 31AcknowledgmentsSlide Number 33BibliographyBibliographyBibliographyBibliographyBibliographyBibliography

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