newest trends and technologies for aero- acoustic ... · technologies for aero-acoustic windtunnel...

Newest Trends and

Technologies for Aero-

Acoustic Windtunnel testingGert Sablon, Director Business Development, STS TEST

Realize innovation.Unrestricted © Siemens AG 2017

Unrestricted © Siemens AG 2017

Siemens PLM Software

Shift towards increased effort to reduce wind noise

50%

30%

10%10%

ICE vehicle

15%

40%30%

15%

10%

Electric Vehicle

Powertrain noise

Road noise

Wind Noise

Ancillary system noise

Other noise and vibrationphenomenon

Source: Leading the Charge – The Future of Electric Vehicle Noise Control, Greg Goetchius, Sound & Vibration, April 2011

Shift in NVH development effort from powertrain towards road noise and aero-acoustic

noise reduction



This results in new investments in Aero-acoustic testing

Wind noise can only be effectively tested in wind

tunnels, but these tests are expensive

Many completely new wind tunnels are

constructed across the globe

BUT mainly the next generation wind tunnel test

complies more advanced testing technology

Goal:

• Increase further the return out of each test

• Get more work done in the wind tunnel

• Reduce the number of iterations and

modifications made to the vehicle



Exterior Wind tunnel Testing

Evolution towards the next generation aero-acoustic testing

First generation Second generation Third Generation NOW

High

Low

Cost

Return of investment



Overview

image

Beyond Testing

Get maximum out of your test campaign

Combining all into one integrated solution

Aero-acoustic testing technologies



Overview

Beyond Testing




http://svcommunity.com/listingitem/photo/view/listing_id/37/photo_id/1080




Overview of the different aero-acoustic testing technologies

Exterior source identificationInterior wind noise measurements S

C

A

L

A

B

L

E

Direct Exterior Measurements

Acoustic Arrays for Source estimation

Direct interior measurements

Surface Pressure Measurements Cfr. GRAS

surface microphones

Additional sensors in Robots or underbody

Interior Sound Source Localization

Why? E.g. to validate aero-dynamic simulation





Direct interior Noise Acquisition

Microphones

mounted on head

rest

Analog

binaural heads(GRAS, B&K, …)

Digital binaural

heads(HEAD HMS)

Support of all possible interior noise sensors, including equalization filters for binaural heads.

Support of digital binaural heads to reduce risks of mistakes in set-up

• LMS SCADAS Mobile VS8-E:

support Voltage, ICP & digital

head

• Support equalization for binaural

• All required post-processing

such as 1/3 octave bands,

spectrums, loudness, articulation

index, …

• Fully realistic replay (incl.

equalization for replay)



Noise source localization and leak detection inside the vehicle

LMS 3D Acoustic Camera

Solid sphere with 54

microphones

Provides best-in-class

results with supreme

directivity & dynamic

range

Geometry scanning

Locate and propagate

sources on the correct

location

Additional post-

processing with ESM &

Bayesian Focalization

for low frequency

Accurate results over

wide frequency range

Efficient batch

processing &

comparison of datasets,

e.g. different frequencies,

yaw angle, wind speed, …

400 Hz



Direct Exterior pressure measurements

Use of special microphones for in-flow acquisition

Quality

G.R.A.S Microphone

HALT Testing

‘Highly Accelerated Live Testing’

5 year warranty

R&D

Inhouse Wind tunnel

For Aero-Acoustic Microphones

Surface microphones

with Turbulence screen

attenuate hydrodynamic

pressure

Surface Microphones

(1/4”)

Nose cones

superior inflow

noise rejection

Flush mounted

(1/4”)



Exterior source localization by means of acoustic arrays

Identification of pressure

distribution around the

vehicle by means of

combination of multiple

arrays

Efficient data

comparison with only

few clicks

EASY comparisons

between results during

test

Wind speed & Yaw

angle automatically

taken into account

No Risks to make

mistakes later

Standard & customized

arrays

best array performance

for your wind tunnel



Exterior source localization by means of acoustic arrays

Coherence analysis

with interior, e.g.

drivers ear but also 3D

Camera

Focus on what is

important

Propagation on plane

surface or full 3D

Increased accuracy by

localizing sources on real

location

Additional post-

processing

Increased performance

& wide frequencies

Ultra fast calculations

Allows to view fully

processed results

continuously during

testing

Original

Coherence with left ear

Evolution calculation

speeds



Overview

Getting maximum out of all used methods by having

access to best technology

Beyond Testing






Overview

Beyond Testing






Overview of the different aero-acoustic testing technologies

Exterior source identificationInterior wind noise measurements S

C

A

L

A

B

L

E

Direct Exterior Measurements

Acoustic Arrays for Source estimation

Direct interior measurements

Surface Pressure Measurements Cfr. GRAS

surface microphones

Additional sensors in Robots or underbody

Interior Sound Source Localization

Why? E.g. to validate aero-dynamic simulationINTEGRATED

SOLUTION





Integrated …

Means it is all measured together, fully synchronized

Acoustic arraysLeft RightTop

3DCam, Binaural Heads

Additional microphones

SCADAS.Mobile inside vehicle

SCADAS.Mobile underneath turn table

SCADAS.Lab

Wind Tunnel control room

Online and

offline Analysis

system

Master control –

integrated with wind

tunnel control system

Integration with

wind tunnel

controller

Data Storage & Management





Why an integrated solution is important for next generation aero-

acoustic testing solution?

Only one system to learn

and operate

BUT there is much

more

1 + 1 = 3

Annotate and save vehicle

attributes, wind speed & Yaw

angle automatically for all

acquired dataMore efficient to set

up

Integration with wind

tunnel controller only

needs to be done once

What is the value of an integrated solution?



Value of fully integrated solution – Example 1

Link binaural head with exterior array by viewing together

LOUDNESS

Configuration A- B

25.000.00 s

Time

20.00

0.00

Am

plit

ude

sone

Time Varying Loudness Vehicle1_Inter_FR:S 95% percentile: 15.5 sone


25.000.00 s

Time

20.00

0.00

Am

plit

ude

sone



Configuration blocked underbody Configuration free underbody

Blocked

Free

Viewing and

comparing results

from different

techniques together

on one screen gives

additional insight

Which exterior sources lead to high loudness?




Link binaural head with exterior array by coherence analysis

Coherence analysis

allows to focus on

sources for interior

noise

Which external source is important for driver’s left ear?

Top Array ResultTop Array Result correlated to

driver’s right ear

FKFS conference 2015, The new Daimler Automotive Wind tunnel, Acoustic properties and measurement system, R. Buckisch, Daimler AG




Link 3D Cam with exterior array by coherence analysis

Coherence analysis

between interior and

exterior array allow

energy flow analysis

Energy flow analysis - Where does an external source leak into the vehicle?

Overall 3DCam results

Top Array Result

3DCam results related to source

selected outside

Exterior Arrays

3D Camera

Remark: above schematic just to explain principle



Overview

Getting new insights from combining technologies

Increasing efficiency by having only one system

Getting maximum out of each used methods by having


Beyond Testing






Overview

Beyond Testing




Am

ou

nt

of in

form

ation

Effic

iency

Effectiven

ess

RO

I



How in practice does an aero-acoustic testing campaign look

like?

Speed [km/h]Yaw Angle [degrees]

100 -15

100 -10

100 …

100 15

120 -20

120 …

… …

160 20

Test modification of a vehicle Analyze

What could cause problems?

Apply modifications: change

mirrors, tape seals, …

In total often many

modifications tested



How to drastically increase testing efficiency?

Make tests run

automatically & real-time

visualization of results

Allow to view fully

processed data in a

minute

In total often many

modifications tested

Allow easy comparison

between processed

datasets with only few

clicks

By doing all this,

Help drastically reducing

number of iterations

Thanks to better analysis,

apply effective

modifications

Test version/modification of

vehicle

Allow easy selection of

what to process &

process in batch




Make tests run automatically & real-time visualization of results

STEP 1: Definition Test Schedule

Step 2: Fully automatic test

1. Bring wind tunnel in requested condition (wind speed, yaw angle)

2. Automatically start test

3. Real-time visualization of all results on separate screens

1. Bring wind tunnel …

Sound quality Left Right Top Interior

Testing configuration

Which wind speeds to test, e.g. 100, 120, 160 kph

Which Yaw Angles to test, e.g. -10, -5, 0, 5, 10 degrees

…




Process and view array results in few seconds

First CPU

algorithm

optimizations

Move

calculations

towards GPU

GPU algorithm

optimizations

Data handling

optimization

Drastic reduction in calculation time thanks to persistent optimizations and move of calculations

towards GPU

Reference:

4000 grid points (full vehicle with 5 cm resolution)

480 frequency lines (400-10000 Hz)

10 sec time data

2012 Dell precision workstation with quad core

Xeon CPU 7 nVidia K5000 GPU




Process and view array results in few seconds

22

1,2

0

5

10

15

20

25

Processing 2012 Optimized processing running on GPU

Total Calculation time (hours)10 seconds versus 5 minutes … So What?

Calculation times build up exponentially!

A wind tunnel test easily consists of 100s of

measurement in the end …



How to drastically increase testing efficiency?Allow easy and fast processing and viewing

Easy selection of processing to be done: configuration, wind speed, yaw angle, frequency range,

method, …

Easy selection of data to be viewed with only few clicks & Easy comparison of results

Calculations running

automatically in batch

View & compare ANY

result

Allows to decide what

modifications to test next

drastically remove total

test time or make test

more effective



Overview

Use all functionality at ALL the time

Be able to use results during test campaign & reduce the

number of tested modifications





Beyond Testing






Overview

Beyond Testing






SimcenterTM 3D

Internoise15-264

Internoise16-450

Exterior aeroacoustics and interior aero-vibro-acoustic wind noise simulations

Exterior noise

Interior noise

using aerodynamic or acoustic loads on the flexible structures

SAE-2015-01-2330

NXNastran

Interior noise



Research activities with

Universities & industrial partners

Partners in research:

• MicrodB (SSL) & G.R.A.S

(microphones)

• Von Karman Institute

• Mutiple universities, e.g. KUL,

ECL

KEY TOPICS of research:

• Further enhance both testing AND simulation

• New source localization algorithms

• Underbody localization techniques

• Transfer of sources towards interior (also with

simulation)

• New sensors and arrays (e.g. for underbody)

e.g. of special sphere



Overview

Full portfolio including simulation through Simcenter

Continued innovation & research

Use all functionality at ALL the time

Be able to use results during test campaign & reduce the

number of tested modification





Beyond Testing






Conclusion

Exterior Wind tunnel TestingFirst generation Second generation Third Generation NOW

High

Low

Cost

Return of investment

Technology Integrated solution Efficiency Trusted partner

newest trends and technologies for aero- acoustic ... · technologies for aero-acoustic windtunnel...

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