This document summarizes a technical report about designing highway vertical axis wind turbines with vortex generators. It discusses how vertical axis wind turbines are well-suited for highways due to their ability to operate in turbulent wind and be placed in urban/city settings. Vortex generators are described as devices that can improve wind turbine performance by reducing flow separation from turbine blades. The document reviews previous research on vertical axis wind turbines for highways and their power generation potential from traffic-induced wind speeds. It aims to optimize highway wind turbines through the addition of vortex generators to maximize power output.

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Design Project REPORT ENGR-491&492: Highway Vertical Axis Wind Turbines
with Vortex Generators
Technical Report · February 2019
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Highway Vertical Axis Wind Turbine with Vortex
Generators
Ara Ibrahim
Mechanical Engineering
Department
American Univercity of Iraq,
Sulaimani
Sulaimani, Iraq
ai15003@auis.edu.krd
Abdullah Fadhil
Mechanical Engineering
Department
American Univercity of Iraq,
Sulaimani
Sulaimani, Iraq
ao14048@auis.edu.krd
Zhalin Khalil
Mechanical Engineering
Department
American Univercity of Iraq,
Sulaimani
Sulaimani, Iraq
zk14046@auis.edu.krd
Rawa Azad
Mechanical Engineering
Department
American Univercity of Iraq,
Sulaimani
Sulaimani, Iraq
ra14168@auis.edu.krd
Abstract— Nowadays, as technology, science and population
are increasing and getting more and more advance every day,
scientist think of manipulating renewable energies because
nonrenewable energies are running out in the world and needs
millions of years to produce again. The main type of renewable
energy is wind and this wind can be converted to electrical
energy by the help of wind turbines. There are two types of wind
turbines, vertical axis and horizontal axis. HAWT are wind
turbines that the blades are rotating horizontally and they are
very efficient turbines but occupies large areas, need constant,
high velocity wind to operate and they need regular maintenance.
However, Vertical axis wind turbines are also efficient turbines,
they are smaller in size and can be installed anywhere in the
cities and highways. This type of turbines can be placed in high
ways where there is constant wind produced by the fast-moving
cars and also the atmosphere. High-Way VAWT like all the wind
turbines converts kinetic energy of the blades to electrical energy,
but this type is small, the blades are different and they can be
placed anywhere to produce electricity for the traffic lights,
street lights, security cameras and many other applications.
Vortex generators can also be attached to this type of wind
turbines which optimizes it to get the maximum power possible to
get from that wind velocity and turbine size.
Keywords— Vertical Axis Wind Turbines, VAWT, Wind
Turbine, Vortex Generators, Highway Wind Turbines.
I. INTRODUCTION
The world is becoming increasingly advanced in
technology, manufacturing and agriculture to fulfill the
demands of human beings as the population increases. These
advancements were mostly accomplished through manipulation
of non-renewable energy sources such as petrol and water for
daily life purposes of operating factories, vehicles, electrical
generators …etc. Upon total consumption of these types of
fuel, however, millions of years are required for them to be
restored. Furthermore, fuels pollute the environment, cause
global warming and numerous diseases. As a substitute for
these types of energy sources, alternative energy generators
must be used by means of manipulating wind for energy
production. Wind turbines are extremely qualified due to their
environmentally friendly characteristics and more importantly,
their high efficiency and energy generation capability.
Wind is highly competent to replace fossil fuel when it
comes to electricity production following its conversion to
mechanical energy. It is abundant and does not pollute the
environment since there is neither chemical reaction nor
emissions nor combustion.
Wind energy has been used for thousands of years in many
parts of the world. In 11th century, Europe and Middle East,
people utilized it in moving boats and in operating agricultural
windmills, wood cutting and in pumping water. In 1970’s
United States, the shortage of oil stimulated the development of
the idea of utilizing wind as an alternative energy source and as
a result, wind turbines have been produced thereafter it slowly
spread out in the world. [1]
Wind energy can be exploited when it’s converted to
mechanical energy. This conversion is performed using wind
turbines. The primary types of turbines are Vertical Axis Wind
Turbine (VAWT) and Horizontal Axis Wind Turbine
(HAWT). Horizontal Axis Turbines contains both downwind
and upwind configurations. HAWTs operate only in high-
speed wind and are more efficient than VAWT but rendered
ineffective during turbulent winds. Vertical Axis Turbines are
smaller in size and operate in low-speed wind; their blades are
designed in a manner that is able to rotate in any direction and
type of wind, whether turbulent or laminar. VAWTs can be
installed in urban areas due to their small size, relatively quiet
and safe characteristics, being easy-to-install and cheapness in
terms of repairs and maintenance. However, HAWTs are only
placed in rural areas where there are no inhabitants due to their
massive size and their need for high speed wind to operate.
[2][3] [4]
There are two types of VAWT, drag type and lift type. The
drag type has high torque but law rotational speed which can
be used for water pumping applications. However, the lift type
has low torque but high rotating speed which can be used for
producing high electrical power. [5]

3. Vortex Generators (VG) are small aerodynamic devices
made of a plate and have an angle. It is placed perpendicular to
the surface of the moving object. These devices are used to
keep and align the air to be attached on the surface of the
moving airfoil and do not allow the air flow to get separated
and interrupted. These VGs are used mainly on airplane wings,
cars and wind turbines to improve aerodynamics by way of
reducing drag increasing lift. Vortex generators can improve
the performance of wind turbines significantly when attached
to their blades in an appropriate way. The blades of turbines are
subject to erosion and roughness which has a negative impact
on the performance of the wind turbines because it causes the
airflow to detach from the blades. However, installing VGs,
which look like small inclined fins, and attaching them on each
blade reduces the air flow separation from the blades of the
turbines and it optimizes the efficiency and operation of the
turbine. As a result, the maximum power of the turbine is
increased. [6] [7]
The effects of VGs are very important and significant to be
considered because they have many benefits to aerodynamic
devices. These benefits include the control of air flow
especially at high speeds because in such circumstances the air
is highly subjected to detachment from the surface and this
creates separation of the air flow and reduces the stability of
the moving or rotating object especially at high speeds. Lift
force is also developed by VGs which is a type of force that
creates swirling or vortex which is spinning of the air that
facilitates and supports motion. [8].
II. LITERATURE REVIEW
Vertical Axis Wind Turbine for Highway Applications
The materials used for this experiment was PVC blades,
steel shafts, aluminum pulley and steel joints. There were 8
blades and they were designed in a semicircular shape so that
when one of them passes, the other takes its position. The
blades where made from PVC pipe because it was cheap and
low cost, there total mass was 1.6 kg. This VAWT was
designed and constructed in a manner that was able to capture
wind from every direction. From a speed of 6.1 m/s, the
induced power was 28W. The efficiency of this type of VAWT
can be increased by changing the blade shapes and sizes and
material and redesign it in a way that can capture more wind so
that more rotation occurs in order to produce more power.
Moreover, instead of PVC plastic Fiber Reinforced Plastic
could be used to get more efficiency of the turbine which
means more power. From this experiment it is concluded that a
well-constructed VAWT can be very useful to humanity and
the environment because it uses renewable energy source to
light up the traffics and street lights and it can be used for other
applications as well. [08]
Feasibility of Highway Energy Harvesting Using a Vertical
Axis Wind Turbine
As it is known, one of the methods of operating turbines is
by wind energy. Not every place in the world has the same
wind energy, some places have lower wind velocities relative
to others. However, this does not mean that turbines should not
be used. One of the advantages in using Vertical Axis wind
turbines is that it can operate in lower wind speeds. For
instance, in Kuwait, the speed of the wind is not that much high
to be manipulated by the wind turbines to produce large
electric energy. However, with the aid for VAWT’s it is placed
in the high ways for lightening up the lights and the traffics.
Statistical analysis based on Malaysia highways indicates
that each day a total of 1.4KW of energy is able to be produced
by vertical wind turbines. This amount of energy is estimated
by the average wind speed caused by the cars and how much of
this wind speed is transmitted to the blades of the turbines. The
average wind speed produced by the cars was 24 m/s which
was able to rotate the blades at 6 m/s which is able to produce
1.4 KW. [19]
Small-Scale Vertical Axis Wind Turbine Design
To design a VAWT many aspects need to be considered.
Javier Castillo [9] explains these aspects in his research about
SMALL-SCALE VERTICAL AXIS WIND TURBINE
DESIGN. The research investigates and experiments with
different parameters to compare results to choose the best
efficient model. This has many stages and processes such as
assuming design parameters and conducting tests like structural
analysis to validate the best choice. The paper concludes based
on acceleration analysis that a three-blade design model is
more efficient than a four-blade model due to its quicker
response at low rpm and its use of brief gusts. The prototype
was made with a different material than the suggested
(NACA0021) due to constraints and proved to be suitable for
the construction of the VAWT on a small and affordable scale.
The test results also showed that when comparing radii at the
same rotational speed, larger ones are more efficient due to
smaller angles of attack and bigger Reynolds numbers that will
cause a bigger blade lift coefficient. [9]
This work [10] looks at designing a vertical-axis wind
turbine to maximize its power coefficient. It has been seen that
the power coefficient of a wind turbine increases as the blade’s
Reynolds number rises. Using a calculation code based on the
Multiple Stream Tube Model, it was highlighted that the power
coefficient is influenced by both rotor solidity and Reynolds
number. By analyzing the factors which influence the Reynolds
number, it was found that the ratio between blade height and
rotor radius (aspect ratio) influences the Reynolds number and
as a consequence the power coefficient. It has been highlighted
that a turbine with a lower aspect ratio has several advantages
over one with a higher value.
The advantages of a turbine with a lower aspect ratio are:
higher power coefficients, a structural advantage by having a
thicker blade (less height and greater chord), and greater in-
service stability from the greater inertia moment of the turbine
rotor.
The study at hand, through design, tries to maximize the
power coefficient of a vertical-axis wind turbine. The power
coefficient seems to be dependent on rotor solidity and
Reynolds number. This was determined using a “calculation
code based on the Multiple Stream Tube Model.” To further
elaborate, as the Reynolds number increases, the power
coefficient of a vertical wind turbine increases. Furthermore,
the study concludes that the Reynolds number is affected by
the ratio of blade height and rotor radius, this in turn, as

4. mentioned above, affects the power coefficient. Hence, there
are advantages to a turbine with a lower aspect ratio: “higher
power coefficients, a structural advantage by having a thicker
blade (less height and greater chord), and greater in-service
stability from the greater inertia moment of the turbine rotor.”
[10]
Flow control on the NREL S809 wind turbine airfoil using
vortex energy
In this paper the writer is looking on the effect of vortex
generator on the aerodynamic performance of airfoil S809. The
author used simulations methods of fluid dynamic in the stand
point of the momentum of the fluid transfer direction and
vortex trajectory. The paper discussed the effect of vortex
generators on the airfoil S809 boundary layer so the vortex
generators enhance the lift coefficient of the airfoil and delay
the stall phenomena by increasing the angle of attack from 14˚
to 18˚, the writer of the paper noticed after testing that the
power of wind turbine increased substantially by the effect of
vortex generators. By comparing the two powers output of the
wind turbines with and without vortex generators the writer
discovered 96.48% increase with using double vortex
generator.
Adding vortex generators will enable us to control the flow
separation and reduce the thickness of the boundary layer of
the airfoil also reduce the drag coefficient, it can be seen from
figures [1] and [2]. The research concludes that the double
vortex generators increase the performance of the wind turbine.
[11]
Fig. 1. Single vortex generator
Fig. 2. Double vortex generator.[11]
Effect of vortex generators on a blunt trailing –edge airfoil
for wind turbine
This research paper is analyzing the parametric effects of
VGs on the blunt trailing – edge airfoil DU97-W-300. They
discovered that VGs have a huge effect on increasing the
maximum lift coefficient and the angle attack for the blunt.
According to the paper the VGs decreases the drag with a coast
which is a slight drag before stall.
In the paper the increment of VG trailing – edge height is
important to generate vortices with higher momentum that will
cause an increase in lift as well as the maximum lift coefficient
of the airfoil DU97-W-300. But also, it has a disadvantage in
drag because of decrease in left to drag ratio. An increase in
VG length led to a negative impact on lift and drag. A
calculated increase in both of the short and long distance
between adjacent parts of VGs has a positive impact on the
flow separation. Finally having big VGs doesn’t mean it will
have a better flow separation. [12]
Electricity Production by Magnet (Maglev Mill)
A method to increase the efficiency of Vertical Axis Wind
Turbines is to use the concept of magnetic levitation in which
the energy production is maximized and friction is reduced. A
study done in India by Pandya, Vyas, and Yadav in 2017 [13],
introduces the use of maglev windmill concept. In the proposed
design, the turbine stator and rotor are magnetically levitated
vertically on a rotor shaft, and functions based on magnetic
repulsion of two or more permanent magnets. The designers
positioned two ring type neodymium magnets on top of each
other in a way that their magnetic fields are opposite so that
they repel. Based on the threshold of the magnets, the wind
turbine will be able to stay suspended in the air without being
attached to anything. An axial flux generator is used to benefit
from the generated air gap perpendicular to the rotating axis
that creates magnetic fluxes. To do that, two wooden base
plates with the repelling magnets in between was used; coils
connected in series were placed on the bottom part, and the
rotating wind turbine blades were connected to the top part.
When the blades rotate, a changing magnetic flux is created
that produces a voltage.
The advantages of maglev wind turbines include the ability
to start producing electricity at very low wind speeds, and keep
functioning at very high wind speeds. In addition, since no
conventional bearings are used, the maintenance cost and space
required is reduced. Due to the mentioned reasons, the authors
concluded that magnetic levitation wind turbines are more
efficient. [13]
Comparative study of different types of generators used in
wind turbine and reactive power compensation.
According to the paper, generators are classified into two
main categories which are synchronous and induction.
Synchronous generator has two types:
• Wound rotor generator:
This type is of generator uses DC current to excite the rotor
windings since it doesn’t use permanent magnets. The output
electricity from the stator is directly connected to the grid, thus
the rotational speed depends on the grid frequency. The
generator does not need any soft-starter or capacitor bank to

5. compensate for the reactive power. The main advantages of
this generator is that a gear box is not required.[15]
• Permanent magnet generator:
As the name says, this type is self-exited and benefits from
permanent magnets instead of induction, therefore, the
generator is more efficient. “The stator of PMSGs is wound,
and the rotor is provided with a permanent magnet pole
system.” [15] PMSGs operate with variable wind speeds and
do not need a gearbox, the rotor can be directly connected to
the shaft. The main disadvantage is that the parts used for
constructing permanent magnet generators are expensive and
complex. Since variable speed is used, a converter is used to
regulate the voltage and frequency. On the other hand, the
generator can be used for any wind speed. [15]
Asynchronous (induction) generator:
This type does not include permanent magnets. The
generators magnetic field is created when an excitation current
is applied. There are two types of induction generators:
• Squirrel cage induction generator:
This type is actually a motor, however when a speed above
the synchronized one is applied, they will turn into a motor.
The shape appears to be similar to a squirrel cage. A gearbox is
used to increase and keep the speed constant. A capacitor bank
is installed in order to make up for the reactive power, and a
soft starter is equipped because the generator is directly
connected to the grid. The advantages of this generator is the
construction simplicity, high efficiency and low maintenance.
However, it uses electricity and power factor is relatively low.
[15]
• Wound rotor induction:
This type of generator is very similar to SCIG, but the
concept of variable speed is practiced instead of constant. A
variable resistance is installed to regulate the output power and
slip. “The advantages of this generator concept are a simple
circuit topology, no need for slip rings and an improved
operating speed range” [16] the disadvantages of this generator
are the limitation of speed range and poor reactive power
control. [15]
III. SOLUTION
Vertical axis wind turbines are very good devices for
generating electricity by converting the wind energy to
electrical energy. However, these turbines sometimes
encounter problems that are significant, and they need to be
considered seriously. These problems may cause low power
generation that results from unsteady wind speed. Wind does
not always exist, or it does not always have the same laminar
velocity. In these conditions, wind turbines encounter problems
in producing electricity because of not uniform blade rotation
which might also harm and break the blades. One other major
problem of VAWT is that it needs a push to operate, this
problem decreases the generated power because it produces its
own produced electricity to initiate the blade’s rotation.
However, the effect of these problems can be reduced, for
instance, for the irregular wind velocities, multiple vortex
generators can be installed which makes the wind attached to
the blades and reduces slip and drag of the blades. The torque
required to rotate the blade can be reduced, hence less energy is
needed to rotate the blades so power will be less consumed by
the turbine itself. The design of the blades also plays an
important role in operating the turbine. They can be designed
in a way that can capture the maximum wind also from
different directions. All the blades must rotate by the same
velocity and at the same time, otherwise the efficiency and the
output power of the turbine will decrease. There are other
alternative energies which might be an option such as
Horizontal Axis Wind Turbines and solar panels but each one
has significant disadvantages, for example the solar panel can
produce a great amount of electricity from solar radiations, but
they occupy large area and in these regions of the world which
is the climate is unclear, dust build up on the panels which does
not allow the sun light to be absorbed completely. HAWT are
very efficient turbines but they are very tall and cannot be
placed in high ways and urban areas besides, the need very
steady and laminar wind velocities.
IV. DESIGN PROCESS
A. Rotor design:
To start with the design of the rotor, many parameters need
to be considered. It’s helpful to fix some parameters to speed
up the optimization process. The parameters include airfoil,
solidity, chord-radius ratio, number of blades, blade material,
blade length, angle of attack, and blade support type and shape.
1) Airfoil:
Choosing the ideal airfoil is one of the most important
factors in designing an efficient and practical VAWT. There's
no doubt that the blade geometry affects the overall
aerodynamics performance of the wind turbine. The thickness
of the airfoil controls the drag lift ratio, more thickness results
in better results when it comes to the start up speed as well as
at low wind speeds. On the other hand, at higher wind speed, a
thicker airfoil will result in too much drag, and reduces the
overall performance at the turbine. Therefore, the traditional
S-VAWT airfoils such as NACA0015, NACA0018,
NACA0021, and du 06-w-200 would usually be the optimum
choice for an airfoil as they still provide a good ratio between
lift and drag, where neither will result in stunting the
performance of the turbine at any wind speed. As for our case,
we are focusing mostly on low wind speed areas, which is
why we chose to go with a thicker air foil design for a better
self-starting behavior and efficiency at low wind speeds. The
two best options for our design were NACA0021 and du 06-
w-200. However, after careful consideration and comparison
of their lift and drag coefficient at different wind speeds, the
conclusion was made that NACA0021 has a better behavior at
low Reynolds number, illustrated in figures [3-4].

6. Figure 3: lift and drag ratio of two airfoils at 50000 Re [22]
Figure 4: lift and drag ratio of the two airfoils at 100,000 Re [22]
It can be clearly seen that at 50,000 Reynolds number, the
NACA0021 has a better lift coefficient. However, when the
Reynolds number Is increased to 100,000, the du 06-w-200
airfoil starts to have a slightly better lift to drag ratio.
Nevertheless, the du 06-w-200 is asymmetric and thinner than
the NACA0021 airfoil and that complicates the manufacturing
process due to the limited machine resources.
2) Solidity:
Another main design factor for straight blade vertical wind
turbines is solidity, which is the total cross-sectional area of
the side of the blades to the frontal swept area [21]. The
symbol used for it is (σ) and equals to the product of number
of blades and chord length over the rotor radius. The increase
of solidity means using more materials and that adds to the
weight and manufacturability cost. Similar to the airfoil
thickness, more solidity increases the power, self-starting
torque, and more drag is produced. Therefore, the solidity
ratio is limited and should be kept at a very low number,
enough to get it start rotating.
3) Chord-Radius ratio:
The chord length of a blade is the distance from the frontal
of the airfoil to the tail, as it can be seen from figure [5], and
the rotor radius is the distance from the rotor shaft to the
chord.
Figure 5 : airfoil profile [20]
These two factors have critical effects on the turbine
aerodynamics. Larger chord length can increase the solidity
and overall performance, to some extent. The increase of rotor
radius on the other hand is limited because of the added load
and manufacturing costs. Therefore, a ratio of chord to radius
must be maintained. Researches indicate that the ratio has to
be between 0.1 to 0.4. [21] The procedure to finding the
ultimate chord length requires complicated calculations and
long procedures, thus, we fixed the chord length to 0.2 meters
and the radius was adjusted according to the ratio. After
cautious considerations and calculations mentioned in the
section, the rotor radius was chosen to be 0.75 meters.
4) Blade Number:
When deciding the number of blades to be used for the wind
turbine, we had to weigh the advantages and dis advantages of
having 1,2,3 or more blades for the turbine. Having one blade
was eliminated quickly since it would cause too much of an in
balance and wouldn’t even start up. The elimination of having
two blades came in tough since it would be able to provide
higher tip speeds, but unfortunately, it would not be as stable
and would require too much maintenance to the point where it
wouldn’t be cost efficient anymore. The two bladed design is
also not non-directional as the tri bladed design, and would
have fewer self-starting capabilities. Any turbine designs that
required 4 or more blades were also quickly eliminated as they
don’t result in much of an increase in power output or
efficiency, and only increase costs. Therefore, we concluded
that the tri-bladed design was the optimum design as it
provides the perfect balance between, stability, performance,
and cost effectiveness.
5) Blade Material:
Choosing the material to use to build the blades is
dependent on the durability, weight and price of the material
used. The common choices for material to use for a wind
turbine, are wood, aluminum, or composite materials such as
fiber glass, or epoxy composites. We eliminated the use of
wood as it is not durable against harsh weathers, specially
humidity. The second material to be taken out of question was
any composite material as it is not only unavailable, but also
too expensive. Finally, we decided to use aluminum, but
unfortunately, we couldn’t create the entire bulk of the blade
using the raw material since excursion machines were not
available. Which is why we ultimately decided to use foam as
the interior of the blade as it is light and composite, and then

7. encased that airfoil with a sheet of aluminum in order to
provide the blades with a good balance of low weight, low
price, and high durability to weather conditions.
The foam was cut using CNC machines as the shape of the
chosen airfoil. Since, the maximum available thickness for the
foam was 18 millimeters and each cost $2, we decided to use
six foams with about 20 centimeters of distance per blade.
They were connected with a screw stud of 1m length in order
to keep it stable and give it enough strength to hold the
aluminum sheet. To further reduce the weight, 4-millimeter-
thick aluminum sheets were used.
6) Blade Length and Angle of Attack:
The angle of attack has a great importance in changing the
lift-drag ratio and performance, but our wind turbine is vertical
and the angle of attack changes constantly according to the
position of the blades. Although changing it might somehow
affect the performance, but due to the limited time we decided
to keep it at 0 degrees. Changing the blade height, on the other
hand, was very limited due to the solidity ratio and the overall
size of the wind turbine. The main purpose of our wind turbine
design is to be used in rural areas, specially highway
midsections, consequently, the most reasonable height we
could choose was 1 meter long.
7) Blade Support Type:
For choosing the blade support type, three options were
available. The blades could be connected through horizontal
studs either at the center (cantilever), at the very two ends of
the blades (simple), or at one-fifth of the total length
(overhang). Since the blades will go through aerodynamical
load and inertial centrifugal force, deformation takes place
along the blades. After calculating bending moment and
deflection for each support type, mentioned in the calculation
section, we came to the conclusion that the cantilever and
simple support types would put the blade structural integrity at
risk. The cantilever option would have the extremities of the
blades bend out of shape, while the simple support would get
the middle section of the blade to cave in, under significant
amount of load. As for the supporting arms, stainless steel rods
of 12mm diameter were used because of the high amount of
strength per weight they could provide.
B. Vortex Generator
Many different designs and shapes of vortex generators are
available. The process of choosing the best design for our VGs
was through researching and testing different samples
including triangular, rectangular and circular shapes. The
combination of rectangular and triangular shapes was found to
be the optimal choice for low speed wind. The dimensions that
was chosen were 6 mm height, 23,66 mm length, 200mm
distance between two sets of VG and 90 mm distance between
the center of each VGs. Since the width of VGs are small
compared to the blades, a base was made under each one to
make the attachment to the blades easier. Also, to make sure
that the base doesn’t cause turbulence, the base was designed
with round edges in order to be more aerodynamic. The edges
on the VGs are fitted with a radius of 2mm which will improve
the aero dynamical performance, see table 1 and figure 6.
TABLE I. DIFFERENT DIMENSION OF VGS
Figure 6: Vortex Generators design using Solid Works
The materials of the vortex generators play an important
part role as well. Multiple options were looked at such as,
aluminum, steel, carbon fiber and reinforced plastic.
Reinforced plastic was found to be the ultimate option due to
its strength, endurance for changes in temperature, light
weight, manufacturability, and cost effectiveness.
C. Generator:
Generators or alternators are one of the main parts in any
wind turbines. The mechanical power from turning the blades
is transformed to a shaft either directly or through a gear box.
The mechanical power is then transformed to electrical power
through generators. Generated power can either be in the form
of direct or alternating current.
Based on all the mentioned generator designs in the
literature review and comparing the advantages and
disadvantages of each one along with the suitability factors, we
decided to use Maglev Permanent Magnet Generators for our
wind turbine. The decision was made because of the high
efficiency and practicality. The wind that will be used for our
wind turbine is a turbulent flow and variable. In addition, we
are dealing with low wind speed. To increase the efficiency
and obtain the maximum power, we decided to use magnetic
levitation system along with the generator in order to decrease
the mechanical friction factor and boost the power output
efficiency. Maglev PMSG are available in the market, however
the cost is relatively high. Because of our limited budget, we
decided to get a small 400-watt maglev/permanent magnet
generator.
VG H(mm) L(mm) Z(mm) S(mm) β(degree)
1 20 40 100 35 15
2 5 16 300 12 15.5
3 5 17 100 10 16
4 5 15 150 12 16.4
5 6 23.66 200 80 15

8. Figure 7: maglev permanent magnet generator
V. IMPLEMENTATION
After conducting research on the wind speed in the
Kurdistan Region of Iraq we discovered that wind speed
varies in different areas around the cities. We noticed that the
wind is stronger outside the cities and that causes problems
when it comes to transportation and storing of energy which
renders it less efficient and costs people in terms of finance.
Our project works on a small scale so it is easier to implement
inside the cities and costs less money to manufacture. Since
the wind is not strong enough, we resorted to using the wind
generated by cars which provides enough wind to power up
wind turbines. We are placing the wind turbine in the middle
of the highways so it will be closer to the houses resulting in
little loss of energy, see figure 8.
Figure 8: Highway vertical axis wind turbines. [17]
This idea has been implemented in a few countries such as
Turkey, Kuwait and Malaysia but none of them used vortex
generators in their design which results in less efficiency and
loud noises. Our project’s aim is to try to tackle the big issue
of not having enough electricity in Iraq. Also, we are trying to
reduce the use of fossil fuels for energy, which produces
emissions that are harmful to the environment. [17]
VI. CONSTRUCTION
The blades for the turbine were made using 6 foam
frames, each 1.8cm thick. They were connected with
increments of about 20cm away from each other by a
steal screw type rod going through the middle, making
up the 1m length of the blade. Then, it was incased with
a 0.4mm thin aluminum sheet that was attached to the
foam using silicon glue. The foam was modeled after the
NACA0021 airfoil design. Figure [9] and Figure [10]
illustrated the construction of the blades more.
Figure 9: Inside of the blades
Figure 10: placement of the foam airfoil
The blades also contain two extruding hinges that
connect them to the main shaft of the turbine using two
75cm long steel studs. The hinges allow for the
adjustment of the angle of attack of the blades and can be
tightened securely afterwards to keep the angle constant
through the turbine's operation.
The steel studs connect back to the main shaft
through two hollow bushes that is tightly attached to the
shaft. The rotor, small tower, generator, and the base
were bought as a complete readymade set.
The vortex generators were made out of modified
PPS (Reinforced plastic) shaped rectangular with
triangular ends. The dimensions of it is as discussed in
the design process. A 3D printer was used to get the
shape that has been chosen. 30 VGs was printed and
placed on the blades. The base of the VG was the same
length as the VG with a width of 4mm and thickness of 1
mm. Also, the edges were flitted with an angle of 2mm

9. to remove sharp edges and increase the aerodynamic
performance, see figure 11.
Figure 11: Manufactured vortex generator
VII. OPERATION
Due to the lack of having a machine that can provide
controllable wind, we decided to use a small fan in order to
operate the wind turbine. The small fan generated enough wind
to rotate the wind turbine and generate almost 10 volts.
Though, it was very hard to maintain a steady flow or increase
the rotational speed of the blades, so we couldn’t do further
testing to see the maximum output and the different that the
VGs will make.
The Vortex generators were tested in the wet lab using the
wind tunnel fan to look at the changes in the air flow. Multiple
extremely thin strings were placed on a blade to visualize the
air flow. Before attaching the vortex generators, we could
clearly see that the wind at the trailing edge separates and gets
very turbulent. After the VGs were attached to the blades at
different angle of attacks, an improvement could be seen while
we changed the angle to about 45 degrees. That proves that
vortex generators help the air to remain attached and reduces
stall.
VIII. EQUATIONS
The wind power is calculated with respect to the area in
which the wind is present as well as the wind velocity. Power
in KW
P=2.14ρAv3*10-3 (1)
Where:
m = mass of air traversing, kg
Air Density (ρ) = 1.2 kg/m3
Area (A) = area swept by the blades of the turbine, m2
Velocity (V) = wind speed, m/s [14]
However, not all the wind power can be converted to
mechanical power due to the absorption of the wind energy by
the blades, meaning that the blades rotate slower than the
actual wind speed. As mentioned, this difference creates a drag
force which can be calculated as:
Fw=Cd.2A.(Uw-Ub)/2 (2)
Where:
A: is the swept area of the blade, m2
Uw: is wind speed, m/s
Cd: is the drag coefficient (1.9 for rectangular form)
Ub: is the speed on the blade surface, m/s [14]
IX. RESULTS AND DISCUSSION
As was expected from the test, attaching VGs to the blade
improved the flow of air and decreased turbulence in
comparison of the flow of air on a blade without VGs. We
found that by changing the angle of attack of the VGs the flow
was affected differently. This means that the addition of VGs
improves the flow and their angle of attack determines the
amount of improvement.
Due to limited resources, there were obstacles in the
construction and testing of the blades which affected the values
of the results obtained. Those obstacles included not having
sufficient resources to do further testing on the blades to obtain
the optimum angle of attack of the VGs, and the efficiency
percent they add to the VAWT. Having said that, further
testing needs to be done with better resources to further prove
our results and give statistical data.
X. CONCLUSIONS
From our project many conclusions can be drawn about the
efficiency of the VAWT and its improvement. The power
output and the efficiency of the VAWT are expected to be
higher with the addition of VGs in comparison with those of a
VAWT without VGs. As for the construction of the VAWT,
the materials and dimensions are chosen based on the literature
review and the calculations made, which helped with
increasing the overall efficiency of the VAWT.
Future experimental data and results will test those
assumptions and provide a clearer understanding of the direct
effects of the materials, dimensions, and added parts as well a
broader understanding of the theories involved.
XI. NOMENCLATURE
m: mass, kg
ρ: Air Density, kg/m3
A: Area, m2
V: Velocity, m/s
Uw: wind speed, m/s
Cd: the drag coefficient
Ub: the speed on the blade surface, m/s
VAWT: vertical axis wind turbine
VG: vortex generators
PMG: permanent magnet generators

10. XII. ACKNOWLEDGMENTS
Our group would like to thank:
Professor Abdelaziz Khlaifat, for guiding and helping
us through the way, and for supervising the project and
giving us important remarks.
Engineer Chalac Hamza for being our co-advisor and
our mentor, for introducing us to the concept of vortex
generators and for dedicating his time to help us and
provide us with necessary information.
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