Suzlon Energy Ltd.

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Design and optimization of wind turbine aerodynamic add-ons

Stig Staghøj KnudsenSenior CFD EngineerSuzlon Blade Science Center

Suzlon Energy Ltd.Suzlon Energy – Brief History

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1995 20071997 2001 2003 2004 2005 2006 2014

ESTABLISHMENT

Acquired Südwind

Acquired AerPac Blade

Expanded into USA

Launched globalization

Chrys-Capital & CITI-Corp

invest in Suzlon

On Stock Exchange

Acquired Hansen

Became 5th largest

WTG manufacturer

in World

Acquired

Senvion (Repower)

24.2 GW installed

across 33 countries

Sale of

Senvion (Repower)

2015

New business:

Solar

2016

Blade Science Center

opens in Vejle, DK

– Presence in 19 countries on 6 continents

– More than 8,000 employees

– Total installed capacity: ~15.8 GW (Sep-2016).

– More than 10,000 turbines at 325 sites

Suzlon Energy Ltd.Installed capacity

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Germany

China

Turkey

India

Brazil

Nicaragua

Japan

North America

U.S.A. 2.684.9

Canada 31.5

Total 2.716,35

Portugal

Europe

Portugal 102.9

Romania 44.1

Spain 233.1

Turkey 109.2

Other 18.9

Total 508,2

Asia

China 928.8

Japan 118

India 9,849.0

Sri Lanka 31.0

Total 9.694,89

Australia

Total 764.4

South America

Brazil 741.3

Nicaragua 63.0

Uruguay 65.1

Total 869,4 South Africa

Total 138.6Uruguay

Romania

Bulgaria

Spain

Sweden

Suzlon Energy Ltd.Technology Hubs

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GermanyHamburg and Rostock – WTG Product Development

Hamburg – Renewable Research Center

Denmark Aarhus – Global Wind&Site, SCADA and Control Systems

Vejle - Blade Science Center

IndiaVadodara – Blade Testing Center

Pune and Chennai – Engineering Center

Bhuj – Materials Testing Lab

NetherlandsHengelo – Engineering and Blade development

U.S.A. WTG Product Development

Technical Services Group

Suzlon Energy Ltd.Aerodynamic add-on Leading edge slat (vorflügel)

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Suzlon Energy Ltd.S111 – Slat – Aerodynamic potential

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-20%

0%

20%

40%

60%

80%

100%

120%

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Cp

/ C

pm

ax [

%]

r/R [-]

CP distribution

Suzlon Energy Ltd.2D design optimization

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Chord

Chord

Camber Camber position

Maximum thickness

Suzlon Energy Ltd.MSES for performance evaluation

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MSES: Fully coupled viscous-inviscid formulation,

like XFOIL, but able to handle multi-element

configurations

Fast execution: 1 min for full polar

Coupled with small BEM code to find local Cp

Suzlon Energy Ltd.2D design optimization outcome

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Suzlon Energy Ltd.

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Wind Tunnel Test Campaign – 3D Effects

Strakes + VGs

Suzlon Energy Ltd.

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Wind Tunnel Test CampaignsEffect of slat

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

0 5 10 15 20 25 30 35 40

Cl

AoA

Effect of slat - 59%, Clean, Re=2.5M

No slat (Exp) No slat (MSES) With slat (Exp) With slat (MSES)

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

-0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5

Chart Title

Suzlon Energy Ltd.2D to 3D

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BEM:150 % of AEP

target

89 %

42 %

47 %

59 %

75 %

42 %

89 %

75 %

47 %

59 %

Increase geometric compatibility

Suzlon Energy Ltd.3D CFD

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No slat

First iterationAEP ↓

Suzlon Energy Ltd.3D CAD model for optimization

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New CAD model• Distribution for parameters to allow for 3D

optimization• Smooth surface generation by meta-

surfaces• Extensions to unload and reduce tip

vortices

Rel. angle distribution

Suzlon Energy Ltd.Slat geometry change

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Final design

Tip extentions

Initial design

Suzlon Energy Ltd.

-20%

0%

20%

40%

60%

80%

100%

120%

140%

160%

November-16 December-16 January-17 February-17 March-17 April-17 May-17

AEP

tar

get

[%]

3D optimization

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Length modification

Tip designInitial design

3D optimization

BEM

Lesson learned: Do 3D

Freeze

Aero

dyn

am

ics

Suzlon Energy Ltd.3D optimized design

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Initial Designfrom 2D

Final 3Ddesign

Suzlon Energy Ltd.Effect of spinner and Cone

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Suzlon Energy Ltd.Structural design

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Suzlon Energy Ltd.

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Suzlon Energy Ltd.Hoisting the slat

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Suzlon Energy Ltd.Comparison with tuft visualization

Separation line (Tufts)

Separation line (CFD) 70 % of AEP target

150 % of AEP target (+VG)

Suzlon Energy Ltd.

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