FACULTY OF ENGINEERING, TECHNOLOGY & BUILT

ENVIRONMENT

EM419 Design Project

Vertical Axis Wind Turbine

Group 4
 Vertical Axis Wind Turbine
Jan - April 2017

Group 4

Supervisors: Ass. Prof.Dr. Mohamed Osman Abdalla

Dr. Yu Lih Juin

Chin Ming Heng 1001438508

Law Jia Hang 1001438531
Tan Chee Yoong 1001438452
Tay Chia Jiunn 1001334173
Dorene Lau Jo Lyn 1001437678

ii
Acknowledgement

Throughout the course of the project, we had the support of our supervisors and we would
like to show our gratitude to them. Without their aid we would have a much more difficult
time in completing the project, with the lack of experience and foresight.

We would like to thank Ass. Prof. Dr. Mohamed Osman Abdalla for his constant guidance
through multiple consultations, providing valuable, information on what is required of our
project.

We would also like to show our gratitude to Dr. Yu Lih Juin for her extensive knowledge in
the ways of presentation which aided us in our own presentation slides.

Lastly we would also like to thank those who have directly or indirectly aided us in the
completion of this project.

iii
Abstract

In this project, we were tasked to design a 10KW vertical axis wind turbine (VAWT) with the
modification for better performance. We were able to analyse several alternative to the
vertical axis wind turbine. The stress simulation, displacement simulation and factor of safety
for our selected design are also highlighted in the report. Besides, there were not many
publications on the modification on vertical wind turbine, hence we had to design and analyse
most of the VAWT design based on our own understanding and guidance from supervisors.
The report will also show the procedure done to fabricate the prototype and any further
improvements which could be made to our design. The costs of fabrication and feasibility of
the modified vertical axis wind turbine will also be included in the report.

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Contents
Acknowledgement ................................................................................................................................. iii
Abstract .................................................................................................................................................. iv
CHAPTER 1 INTRODUCTION ................................................................................................................ 7
1.1 Objective ........................................................................................................................................... 7
1.2 Project Background ........................................................................................................................... 7
1.3 Process Selection .............................................................................................................................. 8
1.3.1 Review of Existing Work and Plan.................................................................................................. 8
1.3.2 Conceptual Design ....................................................................................................................... 10
CHAPTER 2 PRELIMINARY STUDY .......................................................................................................... 11
2.1 Components and Function .............................................................................................................. 11
2.2 Material Selection 2.2.1 Prototype ................................................................................................. 12
2.2.2 VAWT ........................................................................................................................................... 14
2.3 Cost Analysis ................................................................................................................................... 15
CHAPTER 3 Design and Simulation.................................................................................................... 17
3.1 Design Consideration .................................................................................................................. 17
3.1.1 Formula .................................................................................................................................... 17
3.1.2 Calculation ............................................................................................................................... 18
3.2 Main Design Details .................................................................................................................... 19
3.3 Simulation ....................................................................................................................................... 22
3.3.1 Completion of Solid Works Model ............................................................................................... 22
3.3.2 Simulation Result ......................................................................................................................... 24
3.3.3 Simulation on the Vertical Wind Turbine .................................................................................... 25
3.3.4 Simulation of the Frame .............................................................................................................. 27
3.3.5 Simulation on the Darrieus Blades and Cones ............................................................................. 28
3.4 Design of Blade Angle ..................................................................................................................... 33
CHAPTER 4 FABRICATION OF PROTOTYPE ............................................................................................ 35
CHAPTER 5 RESULT AND DISCUSSION .................................................................................................. 43
5.1 Result and Discussion...................................................................................................................... 43
CHAPTER 5 CONCLUSION AND RECOMMENDATION............................................................................ 45
5.1 Conclusion ....................................................................................................................................... 45
5.2 Recommendation............................................................................................................................ 46
5.3 Environmental Concern .................................................................................................................. 46
References ............................................................................................................................................ 48

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Appendix …………………………………………………………………………………………………………………………….............51

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CHAPTER 1 INTRODUCTION

1.1 Objective

There are few objectives set in this project to ensure that the out coming product is fulfilling
the requirement. Staring a project with a clear objectives and specific direction are important
to structure the project along the given time and validate the success.

• To propose unique and innovative designs of a 10kW Vertical Axis Wind Turbine.
• To propose suitable design of rotor blades for maximum efficiency.
• To design all the necessary component of the Wind Turbine adhering to suitable
standards and codes.
• To design suitable power transmission system between the Turbine and the driven
machine.
• To model the Wind Turbine on SOLIDWORKS or ANSYS software, and conduct
stress and deformation analysis for the major parts of the turbine.
• To prototype the design to a suitable scale.
• To conduct performance and cost analysis of the design.

1.2 Project Background

As world population and standard living increase, there is an ever growing demand for
energy. Resources energy can divide by two types which are renewable energy and non-
renewable energy. Non-renewable energy is the natural sources that will run out or will not be
replenished in our life. Most non renewable energy sources are fossil fuels: coal, petroleum,
and natural gas. Meanwhile, renewable energy is the energy resources that is replaced
naturally or controlled carefully and can therefore used without the risk of finishing it all. As
study of the world consumption of energy, it shows that the energy mostly comes from the
non-renewable energy: coal, natural gas and oil which will be empty in future times and need
a million or billion year times to replenish it. Hence, energy sustainable development is
important for the future time to ensure that human have the sufficient energy to carry out their
daily activities especially electricity. From all kind of renewable energy system, wind energy

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system is high relevant because it consider as high conversation performance and achieve
particularly by large scale plants. (1)

The main equipment of wind energy system is wind turbines which help to convert kinetic
energy to electrical energy. Basically, wind turbines consist of rotor shaft, electrical generator,
gearbox and turbine blades which to create the force and produce the torque and thus obtain
the electrical energy. There have two types which are vertical axis wind turbine (VAWT) and
horizontal axis wind turbine (HAWT), both types of wind turbines have their own purpose of
application. The vertical axis wind turbine is suitable for used at the low wind speed country
while the horizontal axis wind turbine is used for high wind speed. Besides that, there is also
a slightly difference in the components of both turbines which horizontal wind turbine
contain of yaw mechanism as shown in figure 1.2.1 cause it is always need to pointed to the
right direction of wind to obtain higher efficiency. One of the advantages of VAWT are that
harnesses the wind from all direction to produce electricity. Besides that, VAWT also
suitable to be installed in urban area since they are easy to transport from one place to another
and also easy to install as compare to HAWT. (2)

Figure 1.2.1 Components of Horizontal Axis Wind Turbine

1.3 Process Selection

1.3.1 Review of Existing Work and Plan

Before proceed with the conceptual studies, a study about the few type of VAWT had been
carry out in order to choose the suitable VAWT as the base design and come out of the
conceptual design with modification on it. The types of VAWT studies are listed as figure 2.0
below:

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 Figure 1.3.1 From left is Savonius Rotor, Darrieus Rotor, H-rotor

Selection of the suitable base VAWT’s criteria is the efficiency which is the output electricity
from the total wind powers into turbine since the output of the important parameter that most
of the people first consideration. From the study, it showed Darrieus Rotor has higher
efficiency compared to the Savonius Rotor and H-rotor Rotor and this is because of the few
reasons. One of the parameters that will affect the efficiency of the VAWT is the propulsion
mechanisms. There are two kinds of propulsion mechanisms which are drag and lift. Darrieus
Rotor and H-rotor is practising lift propulsion mechanism while the Savonius rotors are
practising drag propulsion. For the drag propulsion will have a lower efficiency compared to
the lift propulsion due to the drag of the returning sail into the wind which is often shielded
from the oncoming wind. Another parameter that will affect the efficiency is the swept area
of the VAWT. Darrieus Rotor has the larger swept area that can capture more wind power
compare to another two VAWT.

Although there are still others parameters to be considers such as noise level, blade profile,
blade load, the parameter that to be focused is the efficiency of the wind turbine. Hence,
Darrieus Rotor is chosen as the based wind turbine to be used and modified.

Table 1.3.1: Process Selection Table with Weighted Points

Savonius Rotor Darrieus Rotor H-rotor

Self Starting 1 1 1
Noise 2 2 3 Points Distribution
1-Poor
Cost 3 3 3 2-Average
Efficiency 2 5 2 3-Good
4-Exceptional
Overall Structure 5 5 5 5-Excellent
Total: 12 16 14
*The point given to each types of VAWT is based on the understanding on the studies had
done.

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1.3.2 Conceptual Design

Based on the base VAWT selection, two conceptual designs is proposed.

Table 1.3.2 Conceptual Design

Conceptual Design 1 Conceptual Design 2

The idea of the conceptual design is to enhance the self starting ability of the VAWT. Thus, a
system with drag propulsion mechanism is added to the middle of the Darrieus Rotor.

Conceptual Design 2 is selected as the suitable VAWT for the project. As result shown in the
simulation that the frame help to reduce the deformation of shaft and also it still maintain the
characteristics of the VAWT that harness the wind from all direction to produce electricity.

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CHAPTER 2 PRELIMINARY STUDY

2.1 Components and Function

Table 2.1 Components and Function

Components Functions
Shaft Part that gets turned by the turbine blades. It in turn is
connected to the generator within the main housing
Gear box Take low rotational speed from shaft and increase it to increase
the rotational speed on the generator
Darrieus Blade Rotor blades take the energy out of the wind; they “capture”
the wind and convert its kinetic energy into the rotation of the
hub.
Frame and foundation Enhance the stability of the VAWT system
Bearing Component which used to reduce the friction which generated
between two moving parts and also used to improve the
rotating motion for the moving parts.
Blade Support To support the egg beater shape of the VAWT
Enhancements Accessories Normally is used to strengthen the bonding between one and
another components
Generator Conversion of rotational mechanical energy to electrical
energy
Cone Assist in reducing the starting torque of the VAWT

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2.2 Material Selection 2.2.1 Prototype

Table 2.2 Component and material used for prototype

Component Material
Shaft PVC (1 inch)
Gear box Fishing rod gearbox
Darrieus Blade Polystyrene
Frame Wood
Bearing Ball bearing
Blade Support Brass Rod
Enhancements Accessories Epoxy, Hot glue gun , newspaper
Cone Manila Card

Shaft

Figure 2.1 PVC for shaft

PVC is used as the shaft of the prototype due to the rigidity that able to support the three
blades for the Darrieus Rotor and it is easier to be fabricated which reduce lot more job load
while doing the prototype.

Gear box

Figure 2.2 Fishing Rod Gearboxes

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Fishing rod gearbox is used for the design. There are two main components of this gearbox
which are the main gear and pinion gear. The main gear is to connect the shaft and the pinion
gear. While the pinion gear is to transmit the vertical force to the horizontal force to connect
to the generator.

Darrieus Blade and Blade support

Blade support made of

Brass Rod

Blade made of polystyrene

Figure 2.3 Darrieus Blade

Polystyrene is used in the project because it easier to be fabricated and can meet the desired
shape of blades that needed in prototype, since there are change of size of aerofoil along the
blades. While brass rod is used as a support of the blade in order to form the egg-beater
shape.

Frame

Frame

Ball Bearing

Figure 2.3 Prototype Cone

Wood is used to build the frame and foundation of the prototype because wood have the high
weight density which important to enhance the stability of the VAWT system.

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2.2.2 VAWT

Table 2.3 Component and material used for VAWT

Components Material
Frame Alloy Steel
Shaft Alloy Steel
Darrieus Blade Aluminium Alloy 1060
Cone Aluminium Alloy 1060
Gearbox Alloy Steel
Bearing Ball Bearing

Shaft, Frame, Gearbox

Shaft, frame and gearbox are suggested to make of Alloy Steel. Alloy steel is steel that is
alloyed with a variety of elements in total amounts between 1% and 50% by weight to
improve its mechanical properties. Alloy steels are broken down into two groups: Low-alloy
steels and high-alloy steels. Most commonly, the phrase “alloy steel” refers to low-alloy
steels.

Darrieus Blade, Cone

Darrieus balde and cone are suggested to make of 1060 Aluminium alloy. 1060 Aluminium
alloy is an aluminium-based alloy in the “commercially pure” wrought family. It is typically
formed by extrusion or rolling. It is commonly used in electrical and chemical industries, on
account of having high electrical conductivity, corrosion resistance, and workability. It has
low mechanical strength compared to more significantly alloyed metals. It can be
strengthened by cold working, but not by heat treatment.

Bearing

Ball bearing is a type of rolling element bearing hat uses balls to maintain the separation
between the bearing races. The purpose of the ball bearing is to reduce the rotational friction
and support radial and axial loads. It achieves this by using at least two races to contain the
balls and transmit the loads through the ball. In most applications, one race is stationary and

14
the other is attached to the rotating assembly. In the design project, the ball bearing is using
to connecting to the shaft and it also fixed at the top of the frame.

2.3 Cost Analysis

The table 2.4 is showing the costing for the material that we used in constructing this wind
turbine prototype. The foundation and the supporting structure which made of wood is
recycled material and it has no cost effect on our prototype. The whole project we use only
RM 68.10, because we use quite a lot of recycled material so we save a lot of cost in order to
produce the higher efficiency.

Table 2.4 Costing for prototype

Material Quantity Unit Cost Cost (RM)

(RM)
Generator 1 unit 10.00 10.00

Manila Card 1 piece 1.50 1.50

Bolts & Nuts 10 bolts & nuts - 6.00

Mild Steel L-Bracket 4 mild steel L-bracket
Wire 1 roll (1.5 meter) wire

Hot Glue Stick 2 sets 5.50 11.00

Polystyrene 2 pieces 4.50 9.00

Battery 3 sets 4.70 14.10

Latex Glue 1 unit 5.00 5.00

Styrofoam cutter 1 unit 11.50 11.50

Tota
68.10
l:

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 The costing of a real product wind turbine on the market is around 1170 USD/kW. This
results and data is summarized and get from the 2015 financial report of the two major
European manufacturers.(3) If it is converted to the Malaysia Ringgit, the costing is around
RM4680/kW. This costing is based on the cost per kilowatt, and it is considered the cost of
the wind turbine over the lifespan of the wind turbine, so it is in cost/kW.

This is the total capital cost which including the costing of installing the wind turbine at the
site. The cost including the cost of wind turbine, grid connection cost, construction cost and
also the other cost. Grid connection cost including electrical work, electricity lines and
connection points, and this cost is depending on the condition and location of the site. The
other cost is including the cost used for development and engineering cost.

Table 2.5 Estimated cost for the modified VAWT

Operational Cost (per wind turbine) Percentage (%) Unit Cost (RM/kW)

Wind Turbine 78.00 3650.40

Grid Connection Cost 11.00 514.80

Construction Cost 7.00 327.60

Other Cost 4.00 187.20

Total: 100.00 4680.00

Total Cost of Wind Turbine

7% 4%
Wind Turbine
11% Grid Connection Cost
Construction Cost
78%
Other Cost

Figure 2.4 Operational Cost of Wind Turbine (4)

** This data we get from online resources and the cost is just estimation and it is not
very accurate and not up to date to the latest market.

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CHAPTER 3 Design and Simulation
3.1 Design Consideration

There are few parameters that need to be considered during designing the wind turbine;

• Swept area
• Power and power coefficient
• Tip Speed Ratio
• Blade chord
• Number of blades
• Solidity

Based on the study, some formula and assumption is used to obtain the value that needed in
the wind turbine design.

3.1.1 Formula

Power Coefficient, Cp

Power coefficient is the efficiency of the entire wind turbine system which included the three
main part’s efficiency. The three main part of the wind turbine design are turbine, mechanical
system and also the electrical system.

Formula given for Cp is

𝑃𝑜𝑢𝑡
𝐶𝑝 =
𝑃𝑖𝑛

In order to calculate the actual electrical power produced, Pin. Another formula is given

1
𝑃𝑖𝑛 = 𝜌𝑆𝑉𝑜
2

Which Pout = actual electrical power produced, Pin = wind power into turbine, ρ = air
density (1.225kg/m^3), A = swept area, V0= wind velocity

Tip Speed Ratio

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Tip Speed Ration is the ratio between the tangential speed of the tip of a blade and the actual
speed of the wind. The tip speed ratio is related to efficiency of the wind turbine as the
optimal tip speed ratio can extra as much as power out of the wind as possible.

𝑅𝜔
𝑇𝑆𝑅 =
𝑉𝑜

Which R = Rotor Radius, 𝑉𝑜 = Wind Velocity, ω = angular speed

Solidity

Solidity is defined as the percentage of the circumference of the rotor which contains material
rather than air. Solidity formula is given as

𝑁𝑐
𝜎=
𝑅

Which N = blade number, c = chord length, R = Rotor Radius

3.1.2 Calculation

Some assumption is made based on the design in order to get the value for the detailed design
for the wind turbine.

From the formula of tip speed ratio, angular velocity is calculated with the assumption of
TSR = 4, R = 5m and V0 = 9m/s.

𝑅𝜔
𝑇𝑆𝑅 =
𝑉𝑜

5𝜔
4=
9

𝜔 = 7.2 𝑟𝑎𝑑/𝑠

From the formula of power coefficient, wind power that should enter the wind turbine is able
to calculate with the assumption of Cp = 0.3,

10𝑘
𝑃𝑤 =
0.3

𝑃𝑤 = 33333.33𝑊 ≈ 34𝑘𝑊

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From the wind power enter wind turbine that calculated previous, swept area is able to
calculate with the assumption of V0= 9m/s, ρ = 1.225 kg/m^3.

1
𝑃𝑖𝑛 = 𝜌𝑆𝑉𝑜
2

1
34000 = (1.225)𝑆(93 )
2

𝑆 = 76.1𝑚2

From the solidity formula, blade chord is able to calculate with the assumption of σ = 0.4,

R = 5m, N = 3.

𝑁𝑐
𝜎=
𝑅

𝑅𝜎
𝑐=
𝑁

5(0.4)
𝑐=
3

𝑐 = 0.67𝑚2

3.2 Main Design Details

In this topic is to discuss about the way and method we construct our prototype. There will
also have explanation about the way to construct the wind turbine. For the blades, the

Figure 1.5: Different sizes of blades

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material used is the polystyrene. The polystyrene is cut into different sizes and different blade
chord. There five different sizes of the blade chord, and are stacked together to make a curve
for the blades. The Figure 2.5 shows the size of the blades that used to cut the polystyrene.
Styrofoam cutter is used to cut the polystyrene according to the five sizes, and hot glue gun is
used to stick the different sizes of the polystyrene together and it form a curve, and finally it
become a Darrieus wind turbine blades.

Figure 2.6: Blades after stick all the different size of

polystyrene together

After joining them together, hot glue gun is used to stick the blades on the metal rods that
fixed on the shaft that made from PVC pipe. There are three metal rods fixed around the PVC
shaft, and each of them is 120 degree apart from each other. Hot glue gun is used to attach the
blades on the metal rods. Holes is made on the PVC pipe and fixed the metal rods on the PVC
pipe on the holes at the two ends of the pipe. The shaft is connected to the fishing gear set
and the generator is connected to the output of the gearbox. Wooden foundation is made for
the wind turbine and also the wood structure to support the whole wind turbine. The purpose
of making the wooden structure for supporting the wind turbine is to reduce the friction and
vibration produced when the wind turbine working. If the shaft on the gearbox is placed
without supporting it, the gearbox will withstand a great force and when the shaft rotating,
the friction and vibration will be large and cause energy losses as well as lower the efficiency
of the wind turbine.

For the real product of Darrieus wind turbine, there is a supporting part which they use the
strong cable to stabilize the whole wind turbine. Due to the Darrieus wind turbine has high
center of gravity, the vibration will be higher than the other wind turbine. That’s why the

20
supporting and stabilizing structure is very important. The figure 2.7 shows the stabilizing
structure for the wind turbine.

Figure 2.7: Structure of the VAWT Darrrieus wind turbine (11)

From the figure 2.7 can notice that the wire or cable that supporting the wind turbine need a
large area to fix it on the ground. For our prototype, there are limited space and area so
wooden frame is used as supporting structure to overcome the limitation.

The picture below shows the image of the prototype, and how to stabilize the wind turbine by
using the wooden frame structure.

Figure 2.8: Wind turbine with the supporting structure

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If the cable is used to support the wind turbine, the area of foundation needed is very big to
avoid the cable crash with the turbine blades. Although the wooden structure will block some
of the wind going into the wind turbine, but it is a more suitable method for the prototype.

A small modification is made on the shaft. Three cone-shape blades are fixed on the middle
of the shaft, and it helps in starting torque because the starting torque for the Darrieus wind
turbine is quite small. The blades of Darrieus wind turbine blades are lift type blades, so it
need some time to start rotating the whole shaft. The cone-shape blades are drag type and it
help more on rotating the shaft from it is at rest. This small modification helps to overcome
the limitation faced, which is the Darrieus wind turbine need a high starting torque.

By using the wooden supporting structure for the wind turbine, a ball bearing is put on the top
of the structure in order to straight up the wind turbine and it supporting point is on the top of
the structure in order to reduce the vibration of the shaft. he shaft on the gearbox without the
supporting structure will experience unwanted vibration and there is a friction when shaft
contact with the gearbox. With the supporting structure can fix the gearbox at a place and the
shaft will not contact with the gearbox and friction will not exist. The gear ratio of the gear
system is 1:4, and the output of the gear shaft is connected to the generator. The generator is
fixed on a polystyrene base in order to make sure the power transmission from gear shaft is
stable and no vibration.

3.3 Simulation

3.3.1 Completion of Solid Works Model

Figure3.1: Isometric view of Vertical Wind Turbine.

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Figure 3.2: Darrious Blade with 15 degree.

Figure 3.3: Cube.

Figure 3.4: Frame.

23
 Figure 3.5: Shaft.

3.3.2 Simulation Result

There are some stresses produced across the vertical wind turbine when the force of wind is
exerted on. Most of the affected areas are:
i) The shaft of the vertical wind turbine, which have to support the Darrious blades and cube
blades that develops a higher stress than the others.

ii) The supports of the Darrieus blades and cube blades might be develops a higher stress than
the others.

Therefore, we have done the analysis on the entire Solidworks model and discovered:

i) The shaft of Vertical Wind Turbine that develops a higher stress than others.

ii) The supports of the Darrieus blades and cube blades that develops a higher stress than the
others.

This analysis is being done using the finite element analysis (FEA) simulation from
Solidworks. The test will involve inputting the wind velocity into the design to determine
whether the design may or may not fail and safety factor as well.

24
3.3.3 Simulation on the Vertical Wind Turbine

Assuming the wind velocity flow from the z- axis is 7m/s.

Figure 3.6: The wind flow and by pass through the Vertical Wind Turbine

Figure3.7: Stress analysis on the whole body of Vertical Wind Turbine.

25
Figure3.8: Displacement of frame of vertical wind turbine.

Figure 3.9: Factor of Safety of the Vertical Wind Turbine.

Based on the 4 figures above, show that the simulation for the whole assembly vertical wind
turbine. Firstly, the figure 3.6, 3.7, 3.8 & 3.9 was shown the simulation which is running by
using SolidWorks software. From the figure 3.7, it shows that the maximum stress was
occurred at the frame which are using to support the whole vertical wind turbine and it is
1.231e+004N/m^2. Next, the simulation is the displacement simulation. From the figure 3.8,
shows the maximum displacement point was focused at one of the Darrieus blade and its
maximum value of displacement deformed can be reach to 8.298e-003mm. The reason why

26
the maximum displacement result only focus on one of the Darrieus blade is because the
initial setting was setting the direction of wind is flowing through the z-axis. Other than that,
the figure 3.9 was showing the factor of safety of the whole design of vertical wind turbine is
3. At the end, based through all the results which are taking from all the figure above, are
shown that this vertical wind turbine design is still under the safety condition.

3.3.4 Simulation of the Frame

Assuming the wind velocity which passed through the frame is 7m/s.

Figure3.10: Stress simulation on the frame.

Figure3.11: Factor of Safety of the shaft and foundation.

27
Alloy Steel is steel created when other metals are added to the basic combination of iron and
carbon, improving its properties. And it has 620MPa of yield strength. Therefore, the alloy
steel is selected for the material of the frame because they need the high yield strength to
support the weight of the whole vertical wind turbine. Based on the the analysis conducted,
the results of the frame shown in Figure 3.11 and Figure 3.10 generates a maximum stress of
3.979e+003N/m^2 and a minimum factor of safety of 3.

From this analysis, this SolidWorks model has been a success without falling.

3.3.5 Simulation on the Darrieus Blades and Cones

Assuming the wind velocity which passed through the Darrieus Blades and cones is 7m/s.

Figure3.12:Flow simulation of Darrieus Blades.(Top View)

Figure3.13: Flow simulation of Darrieus Blades.(Side View)

28
Figure3.14: Flow simulation on the cone.

Figure 3.15: Deformation simulation of Darrieus Blades.

29
Figure 3.16: Stress simulation of Darrieus Blades

Figure 3.17: Factor of Safety of Darrieus Blades.

30
Figure 3.18: Deformation simulation of cone.

Figure 3.19: Stress simulation of cone.

31
Figure 3.20: Factor of Safety of cone.

1060 Aluminium alloy is an aluminium-based alloy and has a 27.5742MN/m^2 of yield

strength. So that the 1060 Aluminium alloy is selected for the material of Darrious blades and
cone because this part need higher tensile strength and low density to reduce the problem
deformation and lightweight. Based on the analysis conducted, the results of the Darrieus
Blades shown in Figure3.14, Figure3.15 and Figure3.16 generates a maximum stress of
4.434e+001N/m^2 with a maximum deformation scale of 9.558e-002mm and a minimum
factor of safety of 87. Next is based on the analysis conducted, the results of the cone shown
in Figure3.17, Figure3.18 and Figure3.19 generates a maximum stress of 4.722e+001N/m^2
with a maximum deformation scale of 3.927e-008mm and a minimum factor of safety of 3.5.

From this analysis, this SolidWorks model has been a success without deformation. As the
wind turbines blade having the highest chance to deform while meet the high wind speeds.

32
3.4 Design of Blade Angle

Figure 3.21:Darrieus Blade with 0 degree

Figure3.22:Darieus Blade with 15 degree.

33
Figure3.23: Darieus Blade with 30 degree.

From the figures above, were shown 4 different flow simulation results about the design of
Darrieus blade’s angle. Based on all the figures above, the flow simulation was setting the
wind velocity as 7m/s and gravity force as -9.81m/s^2 at Y component. From the figure
above, shown that the vertices wind turbines blades were hitting by the wind flow. Based on
the Darieus blade with 0 degree, the figure1 shows the wind velocity is starting decrease
while the wind just passed through the bottom left corner’s blade it meet. Next is the figure2,
from this figure shown the wind velocity start to decrease at the same blade with the figure 1.
But, from the figure 2, the area start to decrease the wind velocity is smaller than the figure 1
and it means the efficiency of Darrieus blade with 15 degree is lower than 0 degree. Beside
that, the results of figure3 & 4 showed the wind velocity only start to decrease the velocity
while the wind pass through the bottom right corner’s blade. At the end, based on the results
above, the final decision making to choose the final design of the blade is Darrieus blade with
0 degree.

34
CHAPTER 4 FABRICATION OF PROTOTYPE

Material used:

Wood block, PVC pipe, bearing, newspaper, brass rod, polystyrene, fishing rod
gear box, hot glue stick, manila card, generator, pulley, L-bracket, nail, bolt and
nut.

Tool used:

Polystyrene cutter, paper cutter, sewing machine, drilling machine, hand saw,
hand drill, hammer, hot glue gun, rod cutter, screw driver, pliers, compass,
protractor, ruler, spirit level.

Fabrication of Part

(a) Wind Blade

-The aerofoil shape with different dimensions is draw on the polystyrene.

-The aerofoil is cut out by using the polystyrene cutter.

-By according to the desire curve of blade, the aerofoil is stack and stick with
each other to form blade.

-The blade is wrapped with newspaper.

-The blade is stick on the brass rod to form a wind blade.

-The above steps are repeated to produce a total of three wind blades.

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Figure 4.0: Blade make by polystyrene that stack all different size of aerofoil
together

Figure 4.1: Blade is wrapped by newspaper

Figure 4.2: Blade is stick on the brass rod with hot glue gun

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(b) Cone

-The plan layout of cone is draw on the manila card.

-The plan layout of cone is cut.

-The plan layout of cone is rolled to form a 3D cone.

-The brass rod is stick at the side of the cone as a connection.

Figure 4.3: Cone is connected with the brass rod

(c) Frame

-The wood is cut into desire length and height.

-A hole is make at the centre of the wood.

-The bearing is stick on the surface of the wood at the centre of the hole.

-The two woods with desire height is fixed at the both end of the wood that with
bearing on it.

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 Figure 4.4: Frame of prototype

Fabrication of Overall Prototype

-The hole is drilled on the surface of the PVC pipe.

-The top of PVC pipe is inserted in the bearing.

-The frame is set and fixed on the base by using L-bracket.

-The bottom of PVC pipe is connected with the shaft that runs the gear box.

-The gear box is fixed on the wood in certain height.

-The set of wind blades and cones are fixed in the hole drilled on the PVC pipe.

-The pulley is fixed at the output shaft of the gear box.

-The generator in fixed on the pulley.

-The generator holder is make by polystyrene to hold the position of the

generator.
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Figure 4.5: Fishing rod gear box as prototype gear box

Figure 4.6: Making hole on the shaft

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Figure 4.7: Connecting the shaft with the gear box

Figure 4.8: Fixing bearing on the top of the frame

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Figure 4.9: Fixing the frame on the base with L-bracket

Figure 4.10: Positioning the generator

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 Frame Bearing

Shaft Blade

Cone

Gear box
Generator

Base

Figure 4.11: Full image of prototype

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CHAPTER 5 RESULT AND DISCUSSION

5.1 Result and Discussion

Table 5.1 Design Detail

Blade Geometry and Wind Characteristics

Parameter Symbol Unit Value

Rotor Radius R m 5

Wind Speed V m/s 7 -- 9

Density of Air ρ kg/m^3 1.225

Number of Blades B - 3

Angular speed ω Rad/s 7.2

Thickness dr m 0.21

Swept surface S m^2 81

Output Power Po kW 10

Tip Speed Ratio λ - 4

Solidity σ - 0.4

Blade Chord C m 0.7

Shaft Height H m 12.2

Table 5.1 showed the detail design obtain from the calculation part. Students are able to get
the actual scale of the VAWT and study on the simulation to get the improvement. One of the
studies of simulation is about the blade angle which can refer back to figure3.12. Firstly, the
figure3.12 shown, while the wind flow pass through the Darrieus blade with 0 degree the
wind velocity was decreased immediately at the first blade. This case was showing the
efficiency of the Darrieus blade with 0 degree is higher than other angle design.

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Besides that, with the modification of adding drag device (cones) enables the student to
obtain maximum voltage of 2 V.

There is also some limitation faced while during the prototype. Firstly is about the materials
used for the prototype.

Limitation:

Table 5.2: Component and recycle material decision making

Component / Part Recycle Material Recycle Material

(Previous) (Current)
Tower PVC Pipe PVC Pipe
Rotor Blade (Inner layer) Carton Polystyrene
Rotor Blade (Outer layer) Newspaper Newspaper
Foundation / Base Wood Wood
Frame Wood Wood

By comparing the recycle material used from Table 5.2, the making of inner layer of rotor
blade by using carton is change to polystyrene in the final prototype. Before the fabrication of
prototype, the decision of fabricating the inner layer of rotor blade with carton is make due to
the ease of cutting the desire shape of the aerofoil as well as stacking them together. Yet, in
considering the weight of the rotor blade, polystyrene-make rotor blade is quite lighter than
the carton-make rotor blade. By this replacement of material, the rotor blade is easier to rotate
when they hit by the wind and cause the higher the efficiency.

The rotor blade curve making is another limitation for fabricating the desire blade curve. In
the typical Darrieus vertical axis wind turbine, the upper curve of rotor blade is symmetrical
to the bottom curve of the rotor blade. In the rotor blade making, a slightly non-symmetric of
rotor blade is fabricated. The non-symmetric of rotor blade cause the centre of pressure move
much with changes of angle of attack, so the blade grips is stronger, heavier and therefore
reduce the efficient of the wind turbine.

By considering the cost of material, the bearing that possess for the prototype is not fit for the
tower shaft. The outer diameter of the tower shaft and the inner diameter of possess bearing
are 25mm and 20mm respectively, which is not fit with each other. Due to the bearing is
difficult to find, the alternative way is implemented. A 23mm in outer diameter of pipe is
filed to become 21mm and knock into the bearing.

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Another limitation that faces in the project is the starting torque of the prototype. Like typical
Darrieus vertical axis wind turbine, the starting torque is higher than other types of vertical
axis wind turbine. This is due to the lift force carry out at the aerofoil rotor blade that need
time and enough lift force to move the blade. By referring the rotor blade simulation, the 0
degree angle blade is used in the prototype since it is the most efficient in the angle of attack.

Furthermore, the starting torque in the generator itself is also one of the limitations in this
project. When the shaft of the generator connects fully with the output shaft of the gear box,
the starting torque become higher and reduces the rotation speed of the rotor blade. In order
to optimize the rotor blade rotation speed and reduce the starting torque of the generator, the
adhesive glue is use on the generator shaft to partially touch the output shaft of gear box.

CHAPTER 5 CONCLUSION AND RECOMMENDATION

5.1 Conclusion

After completing this prototype, some problem when constructing the prototype is overcome.
Solution is figured out to overcome the problem and limitation in order to make our prototype
run smoothly and successfully. The factors that will affect the prototype is listed before start
to construct the prototype, select the suitable material for prototype and do some modification
for our Darrieus wind turbine.

Besides, students are able to have more understanding about the working principle, formula
and calculation about the VAWT wind turbine. Furthermore, students also have understood
about the advantages and disadvantages of VAWT wind turbine if compared to HAWT wind
turbine. Students are able to analyze and conduct performance analysis through
SOLIDWORK and also calculation through formula. Cost analysis for this project also listed.

The prototype that constructed can run smooth and generate the electricity at the end and
proved that the design consideration and material selection is suitable for the project which
makes this project success. The objectives of the project have been achieves.

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5.2 Recommendation
Throughout this project, as the prototype shown, the frame of the prototype vibrates when the
wind source is blowing and the rotor blade is rotating. This case happens can reduce the
efficiency and may cause some other components in the system to fail. Since the frame of the
prototype is making by wood and fastening with bolt and nut at the base, it is unstable and
can cause vibration easily when the prototype runs.

In order to make the prototype safer, here is some recommendation that can increase the
stability when operating the prototype. Instead of using wood as a frame, iron is a suitable
replacement for the fabrication of frame. The iron can be weld with each other to form a
frame instead of fastening with bolt and nut which is not solid enough. Moreover, the
material of iron is heavier than wood so that it is able to hold and support the rotating rotor
shaft become better and stronger.

Furthermore, to overcome the vibration issue, the support for the rotor shaft is playing an
important role. Other than making an iron frame to hold the rotor shaft, guy wire is also
recommended. When using the guy wire to hold tight the rotor shaft, the base should be large
enough to enable the guy wire to hold the rotor shaft without intersecting the rotor blade. As
the length of the rotor blade from the centre of rotor shaft increases, the larger the angle of
the guy wire from the top of the rotor shaft, cause the larger the area of the base to enable the
guy wire to meet the base.

5.3 Environmental Concern

Wind energy had claimed that is the widely used renewable energy nowadays. People may
too focus only on wind power and energy obtained which lead to environment issue that need
to concern about. There are two major impact that cause by the wind energy facilities which
are direct impact on individual organism and impacts on habitats structure and functioning.

The wind turbine facilities had caused the fatalities of birds and bats through collision. This
may lead to unbalanced of ecosystem in long term. Besides that, the construction and
maintenance of wind turbines facilities alter ecosystem structure through the vegetation
clearing, soil disruption and potential for erosion. The development of the wind turbine will
also result in the loss of habitat for organism and direct effects on landscapes through
alteration and displacement. The activities which are mineral extraction and cutting of timber

46
are compulsory for wind-energy development, but this activities will affect the ecosystem,
cause the loss of habitat for some species and also the soil erosion.

Hence, the wind industries and government agencies have the responsibility to overcome
these issues.

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References
1. Magedi Moh. M. Saad, N. A. (2014). Comparison of Horizontal Axis Wind Turbines and
Vertical Axis Wind Turbines.

2. Matteo M. Savino, R. M. (2016). A new model for environmental and econimic evaluaton of
renewable energy systems .

3. Milborrow, D. (2016, January 29). Global costs analysis. Retrieved from Wind Power:
http://www.windpowermonthly.com/article/1380738/global-costs-analysis-year-offshore-
wind-costs-fell

4. (2016). Wind Power Technology Brief. IEA-ETSAP and IRENA.

5. Liu, Z. (2015). Global Enegry Interconnection. Elservier Inc.

6. tfcenergy.com. (n.d.). Retrieved from The Wind Energy Challenge:

http://www.tfcenergy.com/wind-energy-how-small-is-small.htm

7. Castillo, J. (2011). Small-scale Vertical Axis Wind Turbine Design. Bachelor's Thesis, 54.

8. Du Lian, J.-H. L.-C. (2016). POWER PREDICTION OF DARRIEUS TYPE WIND TURBINE

CONSIDERING REAL AIR. Korea: Kunsan University University.

9. 5 PL Delafin, T. N. (2016). Effect of the number of blades amd solidity on the performance of

a vertical axis wind turbine. UK: IOP Publishing.

10. 6 Airfoil tools. (n.d.). Retrieved from NACA 0012 AIRFOILS (n0012-il):

http://airfoiltools.com/airfoil/details?airfoil=n0012-il

11. Darrieus vertical axis wind turbine. (n.d.). Retrieved from ecosource.info:
http://www.ecosources.info/en/topics/Darrieus_vertical_axis_wind_turbine

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