Design of a Vertical-Axis Wind TurbineMUN VAWT DESIGN

Group 11Jonathan ClarkeLuke HancoxDaniel MacKenzieMatthew Whelan

Agenda

Phase 1 Recap

Aerodynamic Analysis

Structural Analysis

Regulations

Environment

Economic Analysis

Progress

Image Credits: The Telegram

Phase I Recap

Design a vertical-axis wind turbine for operation in remote communities in Newfoundland and Labrador

The design will Work in conjunction with diesel generators Be simple in design Produce sufficient energy to offset fuel costs Allow for transportation by boat to remote areas

3-bladed H-rotor configuration with DU 06-W-200 airfoils

Aerodynamic Analysis

Preliminary sizing: 320 m2 swept area From wind power density formula:

W/m2 = ½ ρavg CP V3

Various aspect ratios were tested Optimal was 1.25 : 1 (H/D)

Software used for analytical evaluation: QBlade Uses the double-multiple streamtube method Computes VAWT performance at a range of operating conditions Does not account for tower wake or dynamic stall

Aerodynamic Results

Cut-In Speed:7 km/h (2 m/s)

Max Power:130 kW @ 50 km/h

(14 m/s)

Cut-Out Speed:94 km/h (26 m/s)

Rated Power:100 kW @ 40 km/h

(11 m/s)

QBlade results scaled to correct for software limitations

Turbine governed to 35 RPM to reduce loads on shaft and structure

Estimated annual output: 300 MWh 6 m/s average wind speed

Structural Design – Drive Shaft

Material will be AISI 4340 since it is commonly used for large drive shafts

Shaft will be hollow to reduce weight and reduce material costs

Stress in the shaft was calculated due to the maximum torque (~100 000 N-m)

The shaft will have an outer diameter of 30 cm and a thickness of 2 cm Gives a safety factor of 4.9

Structural Design – Tower

A35 structural steel was selected as it is typical for larger structures

The tower was analyzed as a vertical hollow cylinder subjected to wind loads and the weight of the VAWT itself

The distributed wind load on the tower in N/m is:

Structural Design – Tower

The tower will have an inner diameter of at least 2 meters and a wall thickness of 0.0254 m (1 inch)

Using the Von Mises yield criterion on the bending, axial and shear stresses, the maximum stress was 25 MPa Minimum safety factor of 10

Structural Design – Blades

Subject to distributed lift and drag forces along the length of the blade

Max bending moment will occur half way between the supports

Structural Design – Blades

Von-Mises stresses were calculated at various points around the airfoil Max stress of 5.3 MPa when the azimuth angle is 27.5 degrees Max stress allowed for selection of composite material

-1.8 -1.6 -1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2

-0.2-0.15

-0.1-0.05

00.05

0.10.15

0.2

DU 06-W-200 Airfoil

Se-ries1

X-Coordinates

Y-Co

ordi

nate

s

Regulations

IEC 61400-1

Outlines minimum design requirements

20 year design life

Wind Turbine Class I II III S

Vref (m/s) 50 42.5 37.5

Special casesA Iref 0.16

B Iref 0.14

C Iref 0.12

Regulations

Normal operation: Normal turbulence Extreme turbulence

Start up & shut down: Normal wind profile Extreme operating gust

Parked: Extreme wind speed

Environment

0.01 – 0.02 % annual avian collision fatalities

Average 8.2 bird deaths/turbine annually

Location dependent 0 – 27 bird deaths/turbine annually

Economic Analysis

Estimated Capital Cost $500 000.00 Quotes

Annual Maintenance Cost VAWT Turbine - $10 000.00 Diesel Generators - $20 000.00

Projected Fuel Cost in 2015 $3 600 000.00

Payoff Period 3 Years Installation of 5 turbines will cut cost by 15%

Project Status

•On schedule

Structural FEA

•Ahead of schedule

Aerodynamic Modelling - CFD

•Delayed

•Priority given to economic analysis

Detailed Vibrational Analysis

•Ahead of schedule

Detailed Mechanical Design

•On schedule

Detailed CAD Model

•Ahead of schedule

Economic Analysis

•On schedule

Preliminary Structural Design

•On schedule

Aerodynamic Modelling - QBlade

•Delayed

•Priority given to economic analysis

Preliminary Vibrational Analysis

•On Schedule

Preliminary CAD Model

•Delayed

•Waiting on vendors

Selection of Generator

Phase II Phase III

MUN VAWT DESIGNENGI 8926 Mechanical Design Project II

QUESTIONS?http://www.munvawtdesign.weebly.com

Acknowledgements:Thank you to Dr. Sam Nakhla for guidance on structural analysis.