1. Design of a Vertical-Axis Wind Turbine
MUN VAWT DESIGN
Group 11
Jonathan Clarke
Luke Hancox
Daniel MacKenzie
Matthew Whelan

2. Agenda Phase 1 Phase 2 & 3 Project Goals & VAWT Benefits Configuration
Design Selection
Phase 2 & 3
Aerodynamic Analysis
Structural Analysis
Mechanical Components
Economic Analysis
Image Credits: The Telegram

3. Problem Definition and Goals
Design a VAWT for operation in remote communities in Newfoundland and Labrador.
The turbine should:
Work in conjunction with diesel generators
Simple design to reduce manufacturing costs and maintenance issues
Produce at least 100 kW of power at rated wind speed
Able to account for variable wind conditions in the target area

4. Project Scope
The project will examine the following aspects of the VAWT design:
Detailed structural design and analysis
Detailed aerodynamic simulation using computational fluid dynamics
Basic vibrational analysis
Modelling and engineering drawings of mechanical and structural components
Economic analysis

5. Why a Vertical Axis Wind Turbine?
Heavy drivetrain components are located at the base
Easier to maintain
They operate from winds in any direction
No yaw system required
Generate less noise than horizontal-axis turbines

6. Concept Selection: VAWT Configurations
Two main configurations: Savonius and Darrieus
Savonius is drag driven
Darrieus is lift driven
Low efficiency
High efficiency

7. Concept Selection: VAWT ConfigurationsX
Two main configurations: Savonius and Darrieus
Savonius is drag driven
Darrieus is lift driven
Low efficiency
High efficiency

8. Concept Selection: Darrieus Configurations
Simple
Complex
Less Efficient
More Efficient
H-Rotor
Full Darrieus
Helical

9. Concept Selection: Darrieus Configurations
Simple
Complex
Less Efficient
More Efficient
H-Rotor
Full Darrieus
Helical

10. Concept Selection: Airfoil Profiles
Extra thickness – increases blade strength
Higher CL,Max for positive angles of attack

11. Concept Selection: Number of Blades
Capital Cost
Symmetrical Loading
Torque Ripple

12. Concept Selection: Number of Blades
Capitol Cost
Symmetrical Loading
Torque Ripple
3 Bladed

13. Full Darrieus, Helical Darrieus, Savonius
Concept Design
Criteria
Optimal Choice
Alternatives
Configuration
H-Rotor Darrieus
Full Darrieus, Helical Darrieus, Savonius
# of Blades 3
2 to 4
Airfoil
DU 06-W-200
NACA-Series Airfoils

14. Aerodynamic Design Preliminary sizing: 320 m2 swept area
From wind power density formula:
Analytical analysis using QBlade
Developed torque and power curve
Validation using lift & drag equations
Validation using ANSYS CFX
W/m2 = ½ ρavg cP V3
Sizing
Validation
Fl = ½ ρavg A cl W2

15. QBlade Results Rated Power: 100 kW @ 40 km/h Max Power: 130 kW @
Cut-Out Speed:
94 km/h
Cut-In Speed:
7 km/h

16. ANSYS CFX Setup Used 2D simulation
Sacrifices some accuracy for reduced computational demand
Sufficient to validate QBlade results
Fine mesh near airfoils to capture boundary layer effects
Mesh refinement study carried out

17. ANSYS CFX Results Average power: 145 kW at peak operating condition
Does not account for blade tip losses
Sufficient to validate QBlade results

18. Dynamic Model
Suitable under variable wind conditions

19. Structural Design Composite Blade Design Strut Design
E-Glass Fibre and Epoxy
Hollow Square Shape
Wall Thickness: 50 mm
Length: 20 m
Fibreglass Layers: 386
Strut Design
Hollow Cylindrical Shaft
AISI 1045 Cold Drawn Steel
Outer Diameter: 36 cm
Inner Diameter: 28 cm
Length: 7.6 m

20. Structural Design Hub Column Design Tower Design
AISI 1045 Cold Drawn Steel
Outer Diameter: 0.6 m
Inner Diameter: 0.55 m
Length: 8.5 m
Tower Design
A35 Structural Steel
8 meter lengths
Outer Diameter: 3 m
Inner Diameter: 2.95 m

21. Vibrations
At 40 RPM, the aerodynamic and centripetal forces alternate 3 times / cycle
Operating Frequency 40 RPM) = 2 Hz
Maximum Vortex Shedding Frequency = 1.3 Hz
Component
Natural Frequency
Tower
3.4 Hz
Struts
2.5 Hz
Blades
3.3 Hz
Drive Shaft
283 RPM (critical speed)

22. Vibrations
Struts
Blades
Tower

23. Mechanical Components
Drive Shaft
Outer Diameter: mm
Inner Diameter: mm
Length: 7 m
Bearings
Tapered Roller Bearing
Bore: mm
Outer Diameter: mm
Life Span: >20 years
Mechanical Coupling
RB Flexible Coupling

24. Braking and Control
Dynamic braking used to control speed in high winds
Dissipates excess power through a network of resistors
External-contact drum brakes used for shutdown
Spring-applied, electrically released
Fail-safe operation
Compressed air starting system
Cheap and reliable
SIBRE Siegerland Bremsen GmbH

25. Generator Low-speed permanent-magnet generator
Eliminates need for a gearbox
Units are typically custom-built for specific applications
Rated speed can be as low as 10 rev/min
Sicme Motori Srl

26. $ Economic Analysis Estimated Capital Cost Maintenance Cost per year$
Quotes
Maintenance Cost per year
VAWT Turbine - $
Diesel Generators - $
Projected Fuel Cost of 2015 $
Payoff Period
~1M dollars saved annually for an installation of 5 turbines
3 Years

27. Future Work Full 3D CFD analysis Structural Dynamic Model
Foundation / Civil Work
Control System Design
Full Scale Testing

28. Conclusion
Goal: Design a simple, robust vertical-axis wind turbine for use in remote communities
Project goals were met
VAWT design is a viable option to provide power to remote communities

29. ENGI 8926 Mechanical Design Project II
MUN VAWT DESIGN
ENGI 8926 Mechanical Design Project II
QUESTIONS?
Acknowledgements:
Thank you to Dr. Sam Nakhla for guidance on structural analysis.