cristian jos e bottero emship master’s thesis presentation ...€¦ · cristian j. bottero...

Aerojoules project:

Vertical Axis Wind Turbine

Cristian Jose Bottero

Master’s Thesis

presented in partial fulfillment of the requirements for the double degree:

“Advanced Master in Naval Architecture” conferred by University of Liege

“Master of Sciences in Applied Mechanics, specialization in Hydrodynamics, Energetics

and Propulsion” conferred by Ecole Centrale de Nantes

developed at West Pomeranian University of Technology, Szczecin

in the framework of the

“EMSHIP”

Erasmus Mundus Master Coursein “Integrated Advanced Ship Design”

Ref. 159652-1-2009-1-BE-ERA MUNDUS-EMMC

Supervisors: Prof. Maciej Tacza la, West Pomeranian University of Technology

Prof. Herve Le Sourne, ICAM Nantes

Reviewer: Prof. Philippe Rigo, University of Liege

Nantes, February 2011

Aerojoules Project: Vertical Axis Wind Turbine

EMSHIP Master’s Thesis Presentation


Supervised by: Prof. Maciej Tacza la1 and Prof. Herve Le Sourne2

Reviewer: Prof. Philippe Rigo3

1West Pomeranian University of Technology. Szczecin, Poland2ICAM Nantes. Nantes, France

3University of Liege. Liege, Belgium

Nantes, February 27, 2012

Cristian J. Bottero (ZUT–ICAM Nantes) Aerojoules Project February 27, 2012 1 / 50

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation

2 Turbine Design

3 2-D Aerodynamic Analysis


5 Structural Design

6 Simplified Load Estimation

7 Conclusions and Recommendations


Motivation Why VAWTs?

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 MotivationWhy VAWTs?The Aerojoules Project

2 Turbine Design



5 Structural Design





Aerojoules project:



Master’s Thesis







“EMSHIP”







General discussion

Background

Traditionally, HAWTs dominate the large-sized turbine market

Increased interest in the small and medium–sized range

Impulse to new developments in VAWTs

Advantages of VAWTs

No special mechanisms for yawing into wind

Generator closer to ground, simpler maintenance

Lower operational speed: Less noise in urban installation

Disadvantages of VAWTs

Less efficient than horizontal axis wind turbines

Difficulty of modeling the wind flow accurately

Highly dynamic loading on the blade



Aerojoules project:



Master’s Thesis







“EMSHIP”







General discussion

Background




Advantages of VAWTs










Aerojoules project:



Master’s Thesis







“EMSHIP”







General discussion

Background




Advantages of VAWTs










Aerojoules project:



Master’s Thesis







“EMSHIP”







Classification of VAWTs

Drag–driven: Savonius Type Lift–driven: Darrieus Type Combined: Darrieus–Savonius


Motivation The Aerojoules Project

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 MotivationWhy VAWTs?The Aerojoules Project

2 Turbine Design



5 Structural Design




Motivation The Aerojoules Project

Aerojoules project:



Master’s Thesis







“EMSHIP”







Origin and Objectives

About the project

Started by the Ocean Vital Foundation

Model successfully tested at the Vendee Globe 2008

Multidisciplinary project: ICAM, CSTB, Jalais,Garos, AIC

VAWTs oriented to the Nantes region

Three variants: 300W, 1500W and 3000W

Left: Model used for the Vendee Globe 2008


Turbine Design Introduction to Turbine Analysis

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation

2 Turbine DesignIntroduction to Turbine AnalysisPrevious WorksAnalysis and OptimizationBlade Support InterfaceAirfoil Preselection



5 Structural Design





Aerojoules project:



Master’s Thesis







“EMSHIP”







Methods for Turbine Analysis

Aimed at obtaining the global efficiency

Actuator Disk Method

⇒ Maximum efficiency 59.3%

Double Actuator Disk Method

⇒ Maximum efficiency 64%

Rotor Disk Method

⇒ HAWT

Aimed at obtaining the flow characteristics

Blade-Element/Momentum Theory (BEM)

⇒ HAWT

Double Multiple Streamtube Method (DMS)

⇒ Simple flow field

Vortex Method

⇒ Noise propagation analysis

Computational Fluid Dynamics (CFD)

⇒ Efficiency & flow pattern



Aerojoules project:



Master’s Thesis







“EMSHIP”







Methods for Turbine Analysis

Aimed at obtaining the global efficiency

Actuator Disk Method ⇒ Maximum efficiency 59.3%

Double Actuator Disk Method ⇒ Maximum efficiency 64%

Rotor Disk Method ⇒ HAWT

Aimed at obtaining the flow characteristics

Blade-Element/Momentum Theory (BEM) ⇒ HAWT

Double Multiple Streamtube Method (DMS) ⇒ Simple flow field

Vortex Method ⇒ Noise propagation analysis

Computational Fluid Dynamics (CFD) ⇒ Efficiency & flow pattern


Turbine Design Previous Works

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation




5 Structural Design





Aerojoules project:



Master’s Thesis







“EMSHIP”







Performance and main dimensions

Considered constraints

Expected power output

Compromise between aerodynamic and power generation aspects

Aesthetic aspect of the turbine

Interaction with the future manufacturer

Search for an airfoil with the best lift to drag ratio

Parameters set

2m2 square–shape swept area: diameter = height = 1.4m

Three helicoidal blades in composite materials: fiber glass – epoxy

NACA 6412 airfoil, chord = 0.2m



Aerojoules project:



Master’s Thesis







“EMSHIP”







Performance and main dimensions

Considered constraints

Expected power output

Compromise between aerodynamic and power generation aspects

Aesthetic aspect of the turbine

Interaction with the future manufacturer

Search for an airfoil with the best lift to drag ratio

Parameters set

2m2 square–shape swept area: diameter = height = 1.4m

Three helicoidal blades in composite materials: fiber glass – epoxy

NACA 6412 airfoil, chord = 0.2m


Turbine Design Analysis and Optimization

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation




5 Structural Design





Aerojoules project:



Master’s Thesis







“EMSHIP”







Design processProblem

Specification &Design detailing

Investigation& Research

Design

Simulation

Solution issatisfactory?

Prototype & Testing

Validation ofthe simulations

Results aresatisfactory?

Design complete

No

Yes

Yes

No

Red

efin

itio

nof

the

pro

ble

m

Mod

elin

gF

eed

bac

k

Planned: Coupled Analysis

Generation ofthe possible

solutions

Choosing ofa solution

Aeroelasticsimulation


Yes

No

Flu

id–S

tru

ctu

reco

up

led

anal

ysi

s

Adopted: Decoupled Analysis

Generation of the

possible solutions

Simplified aero-

dynamic analysis

Choosing of

a solution

Aerodynamic

simulation

Structural verification

Results are

satisfactory?

Yes

No

Flu

id–S

tru

ctu

re

dec

oup

led

anal

ysi

s



Aerojoules project:



Master’s Thesis







“EMSHIP”










Design

Simulation


Prototype & Testing



Design complete

No

Yes

Yes

No

Red

efin

itio

nof

the

pro

ble

m

Mod

elin

gF

eed

bac

k



solutions




Yes

No

Flu

id–S

tru

ctu

reco

up

led

anal

ysi

s


Generation of the

possible solutions

Simplified aero-

dynamic analysis

Choosing of

a solution

Aerodynamic

simulation


Results are

satisfactory?

Yes

No

Flu

id–S

tru

ctu

re

dec

oup

led

anal

ysi

s



Aerojoules project:



Master’s Thesis







“EMSHIP”










Design

Simulation


Prototype & Testing



Design complete

No

Yes

Yes

No

Red

efin

itio

nof

the

pro

ble

m

Mod

elin

gF

eed

bac

k



solutions




Yes

No

Flu

id–S

tru

ctu

reco

up

led

anal

ysi

s


Generation of the

possible solutions

Simplified aero-

dynamic analysis

Choosing of

a solution

Aerodynamic

simulation


Results are

satisfactory?

Yes

No

Flu

id–S

tru

ctu

re

dec

oup

led

anal

ysi

s


Turbine Design Blade Support Interface

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation




5 Structural Design




Turbine Design Blade Support Interface

Aerojoules project:



Master’s Thesis







“EMSHIP”







Study of design alternatives

Interfaces at intermediate positions along the blades

Concept used on a tested model

Reduction of bending efforts at links

Local reduction of aerodynamic forces

Tip vortex effect not addressed

Interfaces at the blades extremities

Allows works on tip vortex effect

Increased solicitations at links

Might require additional intermediate supports

Designs


Turbine Design Airfoil Preselection

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation




5 Structural Design





Aerojoules project:



Master’s Thesis







“EMSHIP”







General discussion

Criteria for the selection

Aerodynamic performance

Structural strength and stiffness

Aeroelastic behavior

Manufacturability

Maintainability

Noise generation

Available airfoil families

Conventional Airfoils

Four and five digits NACA SeriesOther non–NACA airfoils

Laminar Airfoils

Six and seven digits NACA Series

NREL Families

VAWT Tailored Airfoils



Aerojoules project:



Master’s Thesis







“EMSHIP”







General discussion





Manufacturability

Maintainability

Noise generation




Laminar Airfoils


NREL Families




Aerojoules project:



Master’s Thesis







“EMSHIP”







General discussion





Manufacturability

Maintainability

Noise generation




Laminar Airfoils


NREL Families ⇒ Oriented to HAWT




Aerojoules project:



Master’s Thesis







“EMSHIP”







General discussion





Manufacturability

Maintainability

Noise generation




Laminar Airfoils ⇒ Not good for permanent transient state






Aerojoules project:



Master’s Thesis







“EMSHIP”







General discussion





Manufacturability

Maintainability

Noise generation







VAWT Tailored Airfoils ⇒ Not abundant information



Aerojoules project:



Master’s Thesis







“EMSHIP”







General discussion





Manufacturability

Maintainability

Noise generation



Four and five digits NACA SeriesOther non–NACA airfoils ⇒ Not abundant information




VAWT Tailored Airfoils ⇒ Not abundant information



Aerojoules project:



Master’s Thesis







“EMSHIP”







Preselected NACA four–digit airfoils

NACA 0012 NACA 0015 NACA 0018




Considerations

Manufacturing ⇒ Simple geometries

Design & Analysis ⇒ Well documented airfoil data

Operation & Maintenance ⇒ Low sensitivity to roughness

Optimization ⇒ Wide range of alternative designs



Aerojoules project:



Master’s Thesis







“EMSHIP”







Preselected NACA four–digit airfoils





Considerations

Manufacturing ⇒ Simple geometries

Design & Analysis ⇒ Well documented airfoil data

Operation & Maintenance ⇒ Low sensitivity to roughness

Optimization ⇒ Wide range of alternative designs


2-D Aerodynamic Analysis Preliminary Analysis

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation

2 Turbine Design

3 2-D Aerodynamic AnalysisPreliminary AnalysisCFD Modeling


5 Structural Design





Aerojoules project:



Master’s Thesis







“EMSHIP”







General operational parameters

270◦90◦

0◦

180◦

R

θ

V∞

V∞

VW

VW

ω

Vt

Va

Vr

α

Characteristics

Simplified analysis

Insight into the VAWToperation

Estimation of diverse flowvariables

Background knowledgefor further studies

Important definition:

Tip speed ratio: λ =Vt

V∞=

Blade tip velocity

Wind velocity



Aerojoules project:



Master’s Thesis







“EMSHIP”







General operational parameters

270◦90◦

0◦

180◦

R

θ

V∞

V∞

VW

VW

ω

Vt

Va

Vr

α

Characteristics

Simplified analysis

Insight into the VAWToperation

Estimation of diverse flowvariables

Background knowledgefor further studies

Important definition:

Tip speed ratio: λ =Vt

V∞=

Blade tip velocity

Wind velocity



Aerojoules project:



Master’s Thesis







“EMSHIP”







Study of flow variables

0 30 60 90 120 150 180 210 240 270 300 330 360−50

−40

−30

−20

−10

0

10

20

30

40

50

θ [deg]

α[d

eg]

λ = 1.5λ = 2λ = 2.5λ = 3λ = 3.5

Incidence angle (α) vs. θ

Decreases with λ

Magnitude above 15◦

0 30 60 90 120 150 180 210 240 270 300 330 3600

2

4

6

8

10

12

14

16

18

20

22

24

θ [deg]

‖Vr‖

[m/s

]

λ = 1.5λ = 2λ = 2.5λ = 3λ = 3.5

Incidence velocity (Vr ) vs. θ

Increases with λ

Influences local Reynolds number

Performance study


2-D Aerodynamic Analysis CFD Modeling

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation

2 Turbine Design

3 2-D Aerodynamic AnalysisPreliminary AnalysisCFD Modeling


5 Structural Design





Aerojoules project:



Master’s Thesis







“EMSHIP”







Models characteristics

Zone I

Zone II

Zone III

Zone IV

Blade 1

Blade 2Blade 3

Shaft

Outlet

Inlet Wall

Wall

Interface

Considerations

Vinlet = 5m/s

RANS equations

Realizable k–ε model

Two-Layer approach

All y+ wall treatment

Six values of λ Mesh



Aerojoules project:



Master’s Thesis







“EMSHIP”







Results. Typical torque curve

0 30 60 90 120 150 180 210 240 270 300 330 360−2

0

2

4

6

θ [deg]

Tor

qu

e[N

m]

MT Mt Blade 1 Mt Blade 2 Mt Blade 3

NACA 2415λ = 3

Turbine efficiency: CP =Pa

Pw=

MTa ω12 ρS V 3∞



Aerojoules project:



Master’s Thesis







“EMSHIP”







Results. Comparison of efficiencies

0.5 1 1.5 2 2.5 3 3.5 4−0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

λ

CP

NACA 0012NACA 0015NACA 0018NACA 2412NACA 2415NACA 2418NACA 4412NACA 4415NACA 4418NACA 6412NACA 6415NACA 6418 Overall view



Aerojoules project:



Master’s Thesis







“EMSHIP”








0.5 1 1.5 2 2.5 3 3.5 4−0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

λ

CP

NACA 0012NACA 2412NACA 4412NACA 6412

Curvature effect12% thickness



Aerojoules project:



Master’s Thesis







“EMSHIP”








0.5 1 1.5 2 2.5 3 3.5 4−0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

λ

CP

NACA 4412NACA 4415NACA 4418

Thickness effect4% curvature

Complete



Aerojoules project:



Master’s Thesis







“EMSHIP”







Flow pattern

(a) θ = 246◦ (b) θ = 264◦ (c) θ = 276◦

(d) θ = 305◦ (e) θ = 325◦ (f) θ = 360◦

Pressure [Pa]-160 -108 -56 -4 48 100

NACA 2415 λ = 1

Higher α

Evident flowdetachment

Doublet

λ = 3



Aerojoules project:



Master’s Thesis







“EMSHIP”







Conclusion of the analysis

Effect of curvature increase

Reduction of peak efficiency

Self-starting characteristics notcaptured

Effect of thickness increase

Not clear tendency

From 12% to 15%, apparentimprovement

Results at lower λ

Unexpected behavior:self–starting

Possible simulation problems:dynamic stall

Results at higher λ

Peak value close to theoreticallimit

Results considered qualitativelyfor airfoil selection

Selected airfoils for further analysis

NACA 0015 NACA 2415



Aerojoules project:



Master’s Thesis







“EMSHIP”












Not clear tendency


Results at lower λ







NACA 0015 NACA 2415



Aerojoules project:



Master’s Thesis







“EMSHIP”












Not clear tendency


Results at lower λ







NACA 0015 NACA 2415


3-D Aerodynamic Analysis Simplified CFD Modeling

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation

2 Turbine Design


4 3-D Aerodynamic AnalysisSimplified CFD ModelingDetailed CFD Modeling

5 Structural Design





Aerojoules project:



Master’s Thesis







“EMSHIP”







Simplified model characteristics

Zone I

Zone II

Zone III

Zone IV

Outlet

Inlet Wall

Wall

Interface

Considerations

Equivalent to 2-D models Four mesh sizes Mesh



Aerojoules project:



Master’s Thesis







“EMSHIP”







Results. Efficiency

0.5 1 1.5 2 2.5 3 3.5 4−0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

λ

CP

2-D model3-D model

NACA 0015

Lower peak

Unrealisticat low λ



Aerojoules project:



Master’s Thesis







“EMSHIP”







Tip vortex visualization

∆x = 0.15m ∆x = 0.3m

Vorticity [s−1]0 24 48 72 96 120


3-D Aerodynamic Analysis Detailed CFD Modeling

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation

2 Turbine Design


4 3-D Aerodynamic AnalysisSimplified CFD ModelingDetailed CFD Modeling

5 Structural Design





Aerojoules project:



Master’s Thesis







“EMSHIP”







Detailed model characteristics

Zone I

Zone II

Zone III

Zone IV

Zone V

Zone V

Zone V

Outlet

Inlet Wall

Wall

Interface

Considerations

Equivalent to 3-D Simplified Five mesh sizes Mesh



Aerojoules project:



Master’s Thesis







“EMSHIP”







Results. Inconveniences

Problems

Solution does not converge Divergence of flow variables

Possible causes

Complex geometries Mesh quality

Turbulence model

Possible solutions

Alternative designs for the interface

Increase mesh density

Better turbulence modeling: LES

Constraint

Last stages of involvement



Aerojoules project:



Master’s Thesis







“EMSHIP”








Problems


Possible causes


Turbulence model

Possible solutions




Constraint




Aerojoules project:



Master’s Thesis







“EMSHIP”








Problems


Possible causes


Turbulence model

Possible solutions




Constraint




Aerojoules project:



Master’s Thesis







“EMSHIP”








Problems


Possible causes


Turbulence model

Possible solutions

Alternative designs for the interface ⇒ Not affecting results



Constraint




Aerojoules project:



Master’s Thesis







“EMSHIP”








Problems


Possible causes


Turbulence model

Possible solutions


Increase mesh density ⇒ Computational power limit

Better turbulence modeling: LES ⇒ Computational power limit

Constraint




Aerojoules project:



Master’s Thesis







“EMSHIP”








Problems


Possible causes


Turbulence model

Possible solutions




Constraint




Aerojoules project:



Master’s Thesis







“EMSHIP”








Problems


Possible causes


Turbulence model

Possible solutions




Constraint

Last stages of involvement ⇒ Task continued based on this experience


Structural Design Load Assessment

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation

2 Turbine Design



5 Structural DesignLoad AssessmentTurbine Materials





Aerojoules project:



Master’s Thesis







“EMSHIP”







Origin of loads

Aerodynamic loads

Operational: oscillatory pressure loads, friction loads

Non–operational: pressure loads while braked, friction loads

Inertial loads

Operational: rotation, gravity

Non–operational: gravity, installation and transportation

Accidental loads

Impact of foreign objects

Installation and transportation



Aerojoules project:



Master’s Thesis







“EMSHIP”







Origin of loads

Aerodynamic loads



Inertial loads



Accidental loads





Aerojoules project:



Master’s Thesis







“EMSHIP”







Origin of loads

Aerodynamic loads



Inertial loads



Accidental loads




Structural Design Turbine Materials

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation

2 Turbine Design



5 Structural DesignLoad AssessmentTurbine Materials





Aerojoules project:



Master’s Thesis







“EMSHIP”







Diverse considerations

Previous work

Composite materials selected: glass fiber – epoxy

Isotropic behavior for the analysis

Efforts on the blades

Global bending along the main axis

Global bending along the secondary axis

Torsion

Local effects

Layout optimization



Aerojoules project:



Master’s Thesis







“EMSHIP”








Previous work






Torsion

Local effects

Layout optimization

0◦

0◦

0◦/90◦

±45◦



Aerojoules project:



Master’s Thesis







“EMSHIP”








Previous work






Torsion

Local effects

Layout optimization

0◦

0◦

0◦/90◦

±45◦



Aerojoules project:



Master’s Thesis







“EMSHIP”








Previous work






Torsion

Local effects

Layout optimization

0◦

0◦

0◦/90◦



Aerojoules project:



Master’s Thesis







“EMSHIP”








Previous work






Torsion

Local effects

Layout optimization

0◦

0◦

0◦/90◦

±45◦



Aerojoules project:



Master’s Thesis







“EMSHIP”








Previous work






Torsion

Local effects

Layout optimization

Core

0◦

0◦

0◦/90◦

±45◦


Simplified Load Estimation Motivation

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation

2 Turbine Design



5 Structural Design

6 Simplified Load EstimationMotivationImplementationApplication




Aerojoules project:



Master’s Thesis







“EMSHIP”







Motivation

Considerations

Decoupled analysis

Early structural optimization

Need for aerodynamic loads

3-D CFD: time consuming

Need for alternative solution

Proposal

Preliminary load assessmentbased on 2-D CFD

Early structural analysis

Two iteration loops

Generation of the

possible solutions

Simplified aero-

dynamic analysis

Choosing of

a solution

Aerodynamic

simulation


Results are

satisfactory?

Yes

No

Flu

id–S

tru

ctu

re

dec

oup

led

anal

ysi

s



Aerojoules project:



Master’s Thesis







“EMSHIP”







Motivation

Considerations

Decoupled analysis

Early structural optimization

Need for aerodynamic loads

3-D CFD: time consuming

Need for alternative solution

Proposal

Preliminary load assessmentbased on 2-D CFD

Early structural analysis

Two iteration loops

Generation of thepossible solutions

Simplified aerodynamicanalysis

Simplified structuralanalysis


Choosing of thesolution

Aerodynamicsimulation



Yes

Yes

No

Sec

ond

Iter

atio

nL

oop

No

Fir

stIt

erat

ion

Loop


Simplified Load Estimation Implementation

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation

2 Turbine Design



5 Structural Design





Aerojoules project:



Master’s Thesis







“EMSHIP”







General description2-D pressure distribution

3-D corrected distribution

0 30 60 90 120 150 180 210 240 270 300 330 3600

0.2

0.4

0.6

0.8

1

1.2

1.4

θ [deg]

z[m

]

−80

−60

−40

−20

0

20

40

60

1

θ ⇐⇒ z

Data conditioning

Finalestimation

3-D simplified distribution

0 30 60 90 120 150 180 210 240 270 300 330 3600

0.2

0.4

0.6

0.8

1

1.2

1.4

θ [deg]

z[m

]

−80

−60

−40

−20

0

20

40

60

1

Shape function

0 0.2 0.4 0.6 0.8 1 1.2 1.40

0.2

0.4

0.6

0.8

1

z [m]

f C(z

)

fC1(z)fC2(z)



Aerojoules project:



Master’s Thesis







“EMSHIP”







General description2-D pressure distribution

3-D corrected distribution

0 30 60 90 120 150 180 210 240 270 300 330 3600

0.2

0.4

0.6

0.8

1

1.2

1.4

θ [deg]

z[m

]

−80

−60

−40

−20

0

20

40

60

1

θ ⇐⇒ z

Data conditioning

Finalestimation

3-D simplified distribution

0 30 60 90 120 150 180 210 240 270 300 330 3600

0.2

0.4

0.6

0.8

1

1.2

1.4

θ [deg]

z[m

]

−80

−60

−40

−20

0

20

40

60

1

Shape function

0 0.2 0.4 0.6 0.8 1 1.2 1.40

0.2

0.4

0.6

0.8

1

z [m]

f C(z

)

fC1(z)fC2(z)


Simplified Load Estimation Application

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation

2 Turbine Design



5 Structural Design





Aerojoules project:



Master’s Thesis







“EMSHIP”







Preliminary evaluationApproximation

P′′3D(θj , zk) [Pa]

0 30 60 90 120 150 180 210 240 270 300 330 3600

0.2

0.4

0.6

0.8

1

1.2

1.4

θ [deg]

z[m

]

−100

−80

−60

−40

−20

0

20

40

60

1

3-D CFD simplified model

P3D(θ, z) [Pa]0 30 60 90 120 150 180 210 240 270 300 330 360

0

0.2

0.4

0.6

0.8

1

1.2

1.4

θ [deg]

z[m

]

−100

−80

−60

−40

−20

0

20

40

60

1

Observations

Good general shape correlation

Blunt pressure reduction at tips

Higher peak values

Less oscillatory



Aerojoules project:



Master’s Thesis







“EMSHIP”







Preliminary evaluationApproximation

P′′3D(θj , zk) [Pa]

0 30 60 90 120 150 180 210 240 270 300 330 3600

0.2

0.4

0.6

0.8

1

1.2

1.4

θ [deg]

z[m

]

−100

−80

−60

−40

−20

0

20

40

60

1

3-D CFD simplified model

P3D(θ, z) [Pa]0 30 60 90 120 150 180 210 240 270 300 330 360

0

0.2

0.4

0.6

0.8

1

1.2

1.4

θ [deg]

z[m

]−100

−80

−60

−40

−20

0

20

40

60

1

Observations

Good general shape correlation

Blunt pressure reduction at tips

Higher peak values

Less oscillatory


Conclusions and Recommendations Summary

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation

2 Turbine Design



5 Structural Design


7 Conclusions and RecommendationsSummaryLimitations and Future Work



Aerojoules project:



Master’s Thesis







“EMSHIP”







Summary I

Turbine Design

Several work flows proposed

Flexibility to adapt to the analysis methodology

Blade support at extremities

Continuity in forces, better efficiencyDesigns to reduce negative tip vortex effects

Three alternative designs proposed for the blade–support interface

Efficiencies to be evaluated

Aerodynamic analysis

Wide study with 2-D CFD analysis

Selection of two candidate airfoils

Further studies started with 3-D CFD analysis.

Simplified models captured the tip vorticesMore realistic efficiency curve



Aerojoules project:



Master’s Thesis







“EMSHIP”







Summary I

Turbine Design

Several work flows proposed

Flexibility to adapt to the analysis methodology

Blade support at extremities

Continuity in forces, better efficiencyDesigns to reduce negative tip vortex effects

Three alternative designs proposed for the blade–support interface

Efficiencies to be evaluated

Aerodynamic analysis

Wide study with 2-D CFD analysis

Selection of two candidate airfoils

Further studies started with 3-D CFD analysis.

Simplified models captured the tip vorticesMore realistic efficiency curve



Aerojoules project:



Master’s Thesis







“EMSHIP”







Summary II

Structural analysis

Load assessment

Description of the loads affecting the turbine

Material optimization

Proposal for material use according to solicitations

Development of a simplified method for preliminary studies

3-D pressure distributions estimated from 2-D CFD modelsPreliminary trials result promising


Conclusions and Recommendations Limitations and Future Work

Aerojoules project:



Master’s Thesis







“EMSHIP”







Outline

1 Motivation

2 Turbine Design



5 Structural Design


7 Conclusions and RecommendationsSummaryLimitations and Future Work



Aerojoules project:



Master’s Thesis







“EMSHIP”







Limitations and future work

Inconveniences detected and proposed solutions

CFD models with unsatisfactory results

Improvement of mesh qualityAssessment of the effect of turbulence model and grid–sensitivitySimplification of the domain under studyEfficiency analysis based on alternative methods

Incomplete structural analysis

Proceed with detailed analysis of the material layup

Recommended tasks

Wind tunnel testing

Proceed with model validation and feedback

Material testing

Characterization of unidirectional specimens to improve structural design

Preliminary pressure loads estimation

Continue with the validation and development of the methodology



Aerojoules project:



Master’s Thesis







“EMSHIP”







Limitations and future work

Inconveniences detected and proposed solutions

CFD models with unsatisfactory results

Improvement of mesh qualityAssessment of the effect of turbulence model and grid–sensitivitySimplification of the domain under studyEfficiency analysis based on alternative methods

Incomplete structural analysis

Proceed with detailed analysis of the material layup

Recommended tasks

Wind tunnel testing

Proceed with model validation and feedback

Material testing

Characterization of unidirectional specimens to improve structural design

Preliminary pressure loads estimation

Continue with the validation and development of the methodology


The End

Thank you for your attention.

Questions?


Back Up Slides

Back up slides

Cristian J. Bottero (ZUT–ICAM Nantes) Aerojoules Project February 27, 2012 1 /

Back Up Slides

Aerojoules project:



Master’s Thesis







“EMSHIP”







A method to estimate the performance

0 30 60 90 120 150 180 210 240 270 300 330 3601 5

1

0 5

0

0 5

1

1 5

2

α [deg]F

orce

coeffi

cien

ts

ClCd

Cl(α) ; Cd(α)

0 30 60 90 120 150 180 210 240 270 300 330 36050

40

30

20

10

0

10

20

30

40

50

θ [deg]

α[d

eg]

λ = 1 5λ = 2λ = 2 5λ = 3λ = 3 5

0 30 60 90 120 150 180 210 240 270 300 330 3602

1

0

1

2

3

4

5

6

7

θ [deg]

Tor

qu

e[N

m]

MT Mt B ade 1 Mt Blade 2 Mt Blade 3

0 5 1 1 5 2 2 5 3 3 5 40 1

0

0 1

0 2

0 3

0 4

0 5

0 6

0 7

λ

CP

NACA 0015

α(θ) M(θ) CP (λ)

Vr(θ)

0 30 60 90 120 150 180 210 240 270 300 330 3600

2

4

6

8

10

12

14

16

18

20

22

24

θ [deg]

‖Vr‖

[m/s

]

λ = 1 5λ = 2λ = 2 5λ = 3λ = 3 5

Main aspects

Based onairfoil data

Disregardsinterference

Dependent onquality of data

Questionableresults

Unknown flowcharacteristics

Preliminary 2D Analysis


Back Up Slides

Aerojoules project:



Master’s Thesis







“EMSHIP”







2-D. Efficiencies. Complete results

0.5 1 1.5 2 2.5 3 3.5 4−0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

λ

CP

NACA 0012NACA 0015NACA 0018NACA 2412NACA 2415NACA 2418NACA 4412NACA 4415NACA 4418NACA 6412NACA 6415NACA 6418 Overall view


Back Up Slides

Aerojoules project:



Master’s Thesis







“EMSHIP”








0.5 1 1.5 2 2.5 3 3.5 4−0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

λ

CP




Back Up Slides

Aerojoules project:



Master’s Thesis







“EMSHIP”








0.5 1 1.5 2 2.5 3 3.5 4−0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

λ

CP




Back Up Slides

Aerojoules project:



Master’s Thesis







“EMSHIP”








0.5 1 1.5 2 2.5 3 3.5 4−0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

λ

CP



2D Analysis


Back Up Slides

Aerojoules project:



Master’s Thesis







“EMSHIP”







2-D. Torque variation with λ.

0 30 60 90 120 150 180 210 240 270 300 330 360−4

−2

0

2

4

6

8

θ [deg]

Tor

qu

e[N

m]

λ = 1 λ = 1.5 λ = 2 λ = 2.5 λ = 3 λ = 3.5

NACA 2415


Back Up Slides

Aerojoules project:



Master’s Thesis







“EMSHIP”







2-D. Reynolds number variation with λ.

0 30 60 90 120 150 180 210 240 270 300 330 360

0.5

1

1.5

2

2.5

3

·105

θ [deg]

Re

λ = 1.5λ = 2λ = 2.5λ = 3λ = 3.5

Flow variables


Back Up Slides

Aerojoules project:



Master’s Thesis







“EMSHIP”







Flow pattern

(a) θ = 246◦ (b) θ = 264◦ (c) θ = 276◦

(d) θ = 305◦ (e) θ = 325◦ (f) θ = 360◦

Pressure [Pa]-150 -100 -50 0 50 100

NACA 2415 λ = 3

Lower α

Lower intensityvortices

λ = 1


Back Up Slides

Aerojoules project:



Master’s Thesis







“EMSHIP”







Blade support design.Alternative 1, transition element.


Back Up Slides

Aerojoules project:



Master’s Thesis







“EMSHIP”







Blade support design.Alternative 2, smoothed joint.


Back Up Slides

Aerojoules project:



Master’s Thesis







“EMSHIP”







Blade support design.Alternative 3, chamfered edge.

Turbine design


Back Up Slides

Aerojoules project:



Master’s Thesis







“EMSHIP”







2-D model. Mesh general view.


cristian jos e bottero emship master’s thesis presentation ...€¦ · cristian j. bottero...

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