Parametric Design Studies - PowerPoint Presentation

Slide1

Parametric Design Studies of the Helicopter Rotor Noise using Variable-Fidelity Methods

Dirk Rabe, Gunther WilkeDLR Institute of Aerodynamics and Flow TechnologyMay 17th, 201874th AHS Phoenix, Arizona

> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018

DLR.de • Chart

1

Slide2

ContentMotivationMethodology

Comparison of Various Methods for selected Rotor Blades

Results of the

Parametric

Design Study

Conclusion and Outlook

> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018

DLR.de • Chart

2

Slide3

MotivationMethodology

Comparison of Various

Methods for

selected

Rotor BladesResults

of the

Parametric

Design StudyConclusion and Outlook

> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018

DLR.de • Chart

3

Slide4

1. MotivationMultidisciplinary development of

rotor blades takes timeERATO (DLR/ONERA) design process – 8 yearsERATO  Blue Edge® – 17

years

 25

years

of design and

development

for

quiet rotor bladeDevelopment tools range from BET+wake models to

higher order CFD

Goal:

Find fast

and accurate methods for aeroacoustic design studies

> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018

DLR.de • Chart 4

ERATO blade design

H160

with Blue Edge® blade

Source: www.Airbushelicopters.asia

Slide5

MotivationMethodology

Comparison of Various Methods

for

selected

Rotor Blades

Results

of the

Parametric

StudyConclusion and Outlook> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018

DLR.de • Chart

5

Slide6

2. Methodology> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018

DLR.de • Chart 6Fluid-Structural-

Numerical

process

chain

Comprehensive

Code

HOST

Flow/

Vortex

solution

HOST, UPM,

FLOWer

FW-H-

Aeroacoustic

Code

APSIMSoundPressurePropagation

Slide7

2.

Methodology> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018DLR.de • Chart 7

BET + wake

models

:

airfoil tablesprescribed/free wake

Panel method:incompressible (

correction

factor)inviscidCFD:higher order schemes40 Mio. grid cells

UPM

Oneshot

UPM

Coupled

UPM

17

49

2

FLOWer4

Euler

RANS

80

144

0.1

HOST

P.WAKE

F.WAKE

Radial

39

Chord

1

Azimuth

[°]

2

Slide8

2.

Methodology> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018DLR.de • Chart 8

BET + wake

models

:

airfoil tablesprescribed/free wake

Panel method:incompressible (

correction

factor)inviscidCFD:higher order schemes40 Mio. grid cells

UPM

Coupled

UPM

17

49

2

FLOWer4

RANS

80

144

0.1

HOST

P.WAKE

Radial

39

Chord

1

Azimuth

[°]

2

Slide9

MotivationMethodology

Comparison of Various Methods for selected Rotor Blades

Results

of

the Parametric Design

Study

Conclusion

and Outlook> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018DLR.de • Chart 9

Slide10

3. Comparison of Various Methods for selected Rotor Blades

Wind tunnel tested rotor bladesDifferent blade tip shapes by

aeroacoustic meansInvestigation

of

6°

descent flight> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018

DLR.de • Chart 10

HART

II

N

B

[-]

4

R [m/

ft

]

2.0/6.56

M

tip

[-]

0.638

μ

[-]

0.150

C

t

/

σ

[-]

0.594

HARTII

7AD

ERATO

Wind

tunnel

blade:

7AD

4

2.1/6.89

0.660

0.154

0.533

ERATO

4

2.1/6.89

0.616

0.1650.631

Slide11

3. Comparison of Various Methods for selected Rotor

Blades – HARTII> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018DLR.de • Chart 11

HARTII –

noise

carpets

–

8–40

BPF – SPL [dB]

Experiment

P.WAKE

Coupled

UPM

RANS

fair(

o

)

good

(+

)good

(

+

)

Assessment:

Slide12

3. Comparison of Various Methods for selected Rotor

Blades – 7AD> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018DLR.de • Chart 12

7AD –

noise

carpets

–

8–40

BPF – SPL [dB]

Experiment

P.WAKE

Coupled

UPM

RANS

bad

(

-

)good

(+)

fair(

o

)

Assessment:

Slide13

3. Comparison of Various Methods for selected Rotor

Blades – ERATO> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018DLR.de • Chart 13

ERATO –

noise

carpets

–

8–40

BPF – SPL [dB]

Experiment

P.WAKE

Coupled

UPM

RANS

fair(

o

)

good(

+)

fair(

o

)

Assessment:

Slide14

3. Comparison of Various Methods for selected Rotor Blades – Review

> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018DLR.de • Chart 14

Methods

HARTII

7AD

ERATO

P.WAKE

o

-

o

F.WAKE

o

-

-

Oneshot

UPM

++

o

+

Coupled

UPM

+

+

+

Euler

+

o

o

RANS

+

o

o

Average

simulation

resources

[

cpuh

]

Assessment

of

noise

carpets

Slide15

MotivationMethodology

Comparison of Various

Methods

for

selected Rotor BladesResults of

the Parametric Design Study

Conclusion

and Outlook> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018

DLR.de • Chart 15

Slide16

4. Results of the Parametric Design Study – Baseline

7AD baseline:ERATO flight statelower Mtip 2 dB

noise reduction

Use

of validated methods:P.WAKECoupled UPM

Investigated parameters:an/dihedral

twist

> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018

DLR.de • Chart 16

Rotor blade

definition

of

the 7AD baseline

Slide17

4.

Results

of

the Parametric Design Study – Anhedral

> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018

DLR.de • Chart

17

P.WAKECoupled

UPM

Best sample

Samples

Slide18

4. Results of the Parametric Design Study – Anhedral

– P.WAKE> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018DLR.de • Chart 18

P.WAKE –

anhedral

–

noise

carpets

–

8–40

BPF – SPL [dB]

Baseline

Best Design

Difference

Slide19

4. Results of the Parametric Design Study – Anhedral

– Coupled UPM> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018DLR.de • Chart 19

Coupled

UPM –

anhedral

–

noise

carpets

–

8–40

BPF – SPL [dB]

Baseline

Best Design

Difference

Slide20

4.

Results of the

Parametric Design Study – Anhedral – Coupled UPM

> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018

DLR.de • Chart

20

Coupled

UPM –

anhedral

– comparison of vortex

fields

Slide21

4. Results of the Parametric Design Study – Twist

> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018DLR.de • Chart 21

P.WAKE

Coupled

UPM

Twist

distribution

Best sample

Samples

Slide22

4. Results of the Parametric Design Study – Twist – P.WAKE

> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018DLR.de • Chart 22

P.WAKE –

twist

–

noise

carpets

–

8–40

BPF – SPL [dB]

Baseline

Best Design

Difference

Slide23

4. Results of the Parametric Design Study – Twist – Coupled

UPM> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018DLR.de • Chart 23

Coupled

UPM –

twist

–

noise

carpets

–

8–40

BPF – SPL [dB]

Baseline

Best Design

Difference

Slide24

4. Results of the Parametric Design Study – Review of noise

reduction> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018DLR.de • Chart

24

An/

Dihedral

Twist

P.WAKE

(max.

SPL /

largest

reduction

)

-1 / -10

-3 / -3

Coupled

UPM

(max.

SPL /

largest

reduction

)

-6 / -7

-1 / -7

Slide25

MotivationMethodology

Comparison of Various

Methods

for

selected Rotor BladesResults

of

the

Parametric Design StudyConclusion and Outlook> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018

DLR.de • Chart 25

Slide26

5. Conclusion and OutlookConclusion:

Investigation of wind tunnel tested rotor blades:best results were found using

free-wake coupled panel

method

CFD

results roughly 4 dB under estimated for all

test cases, higher grid

resolution

necessaryPerformed parametric design study with anhdral and twist:design trends

of

wake

model and panel

method align

, prediction

discrepancies existdihedral

showed most promising

resultsOutlook: double check parametric design study results with

CFD optimization study

,

combination

of

design

parameters

multi-

objective

investigation

(

aerodynamics

+

aeroacoustics

)

> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018

DLR.de • Chart

26

Slide27

Thank you for your attention

.Are there any questions?> AHS74 > Dirk Rabe • Parametric Design Studies of Helicopter Rotor Noise > 17.5.2018

DLR.de • Chart 27