JNTU B.Tech Report: Wind Augmentation Device and Power Generation

This report analyzes a custom-constructed small-scale wind augmentation device with a wind-guide attachment, focusing on improving wind power generation. The introduction highlights the history and importance of wind energy, discussing different types of wind turbines, their components, and the benefits of wind power, including its role in reducing greenhouse gas emissions and promoting renewable energy. The report also addresses the current status of wind energy, including global production and the adoption of wind energy, along with its advantages and disadvantages. The document further explores wind power augmentation techniques, mentioning various methods like cylindrical obstruction concentrators, tip vanes, and diffuser augmented wind turbines. The study references existing research on wind augmentation devices and their influence on power generation, emphasizing the potential of wind energy as a sustainable and environmentally friendly source of power.

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ANALYSIS AND COMPARISON OF A CUSTOM CONSTRUCTED SMALL-SCALE WIND
AUGEMENTATION DEVICE WITH A WIND-GUIDE ATTACHEMENT TO IMPROVE
WIND POWER GENERATION
(May 2017)
Bhavana Kashibhatla, B.Tech., JNTU
Chairman of Advisory Committee: Dr. Ulan Dakeev

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CHAPTER - 1
INTRODUCTION
Wind energy is one of the most reliable and abundant sources of renewable energy on this
planet. The humankind has used it for centuries as there are estimates that people were using this
type of energy as far as 4,000 years ago. In the year 1700, it was employed by the king of
Babylon for irrigation purposes (Ackermann & Kuwahata, 2013). The wind was also for
grinding grain by several farmers. It is also surprising to note that one of the earliest windmills
had the vertical axis of rotation. The people use braided mats or sails for rotating these windmills
across the vertical axis. These windmills had an operational advantage as they were independent
of the direction of the wind.
History of Wind Power
The wind power was initially utilized by humans in the form of irrigation pumping, sailboats
and garn milling. The history of wind power can easily be tracked back to the ancient 6,000
years ago. The sails, ships and sailboats were used on the Nile River though its water, in Egypt.
The earliest known use of wind power was represented by the sailboats. Although as per today’s
standard, it is considered to be a rudimentary use of wind but the technology impacted the
development of the current sail-type windmills (Hansen, M. O., 2015). The first documented
proof of the existence of such mills dates back to 12th century. However, the ability to study the
wind power across the horizontal axis was the first to measure in the 20th century (Kuwahata
et.al, 2013).
There are two types of wind turbines. One is built with high speed and is intended to generate
electricity whereas the other one is built for low wind speeds (Wahab et al. 2008). The major

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components of Wind turbines include a rotor with a set of blades with a rotor hub which is seen
to deflect the airflow by creating a force on the blades. Due to this, a torque is produced on the
shaft and the rotor is seen to rotate around the horizontal axis attached with a generator and a
gearbox. All this is present inside the nacelle present with other important electrical parts with
the tower end. Electricity is generated moving down from the tower to the transformer which is
then converted from voltage (usually 700V, 33000V for countrywide grid, 240 V for the personal
use). The core windmills are termed as horizontal axis wind turbine (HAWT) and the vertical
axis wind turbine (VAWT). The windmills using the horizontal axis of rotation are relatively
new as compared to vertical axis ones.
United States and Wind Power
Due to increasing high-energy costs, the government and the people are becoming highly
concerned towards global warming, pollution and feel financially strapped at the same time
(Bollen, Hers & Zwaan, 2010). With around 30 percent of the total world reserves, the United
States have a vast coal supply (Hook & Aleklett, 2010). The annual production of United States
is almost twice as compared to India and lacks only behind China (Hook & Aleklett, 2010). But
it has been noticed that the US reserves are concentrated only in few states and have
considerably decreased from 29.2 MJ/kg 23.6 MJ/kg in the period of 1950-2007 due to
movement of subbituminous western coals by US (Hook & Aleklett, 2010). The production of
one kilowatt hour (kWh) of electricity from coal is seen to produce 1kg of Carbon Dioxide
(CO2), more than 200 grams of waste amounts of several metals and ash, seven grams of
nitrogen oxides, sulfur oxides and particulates are released such as Methane (CH4), hydrogen
sulfide (H2S), hydrocarbons ethane (C2H6), etc. (Stracher & Taylor, 2004).

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Benefits of Wind Power
According to Klingenberg (1996), CO2 levels were around 345,000 parts per billion in 1996 as
compared to 290,000 parts per billion decades ago (Graedel & Crutzen, 1989). According to the
U.S. Department of Energy, 2013, the dependency of the fossil fuels can be reduced using the
wind energy as there is no emission of greenhouse gases. Although the generation of electricity
is not just one cause of increasing CO2 level in the atmosphere but it contributes to a major share
of CO2 emission (Graedel & Crutzen, 1989). Therefore, the reduction of greenhouse gases in the
atmosphere can be done by environmentally friendly electricity generation using wind power.
The tunnel attachment of the wind has the ability of capturing low speeds of the winds especially
at the lower altitudes which might lead to deduction in the wind turbines and will lead to over
improvement of the efficiency. A vital step can be taken by the wind power in the field of
renewable source for production of energy. The current status of wind energy is promising. The
fourth edition of Global Wind Energy Outlook claimed that the wind energy constitutes 3.5% of
global electricity production. The share in power generation is estimated to reach 12% by the
year 2020 (Kuwahata et.al, 2013). At the end of the year 2012, the total global production of the
Wind Energy was 282 Giga Watts showing an increase of 44% from the year 2011 (Kuwahata
et.al, 2013). The installation of wind energy had reached its peak during the year 2012, but after
the same year, the total production of wind power generation has decreased due to several
reasons. In fact, the installation of wind energy for electricity generation falls to 18.7% which is
the lowest in the past two decades.
The United States has also gained the global momentum, and the growth rate in the
country was estimated to be around 27.9% during the year 2012. The total electricity produced in
the United States from wind energy was 140 terawatt-hours constituting the 3.5% of the total

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energy produced from entire sources (Armentrout & Armentrout, 2009). The US Department of
Energy (DOE) has accelerated its efforts to install wind and water power generation capability of
the country. The DOE also issues loans and guarantees to install wind electricity generation. The
DOE has estimated to supply 20% energy from the wind generation by the year 2030
(Armentrout et.al, 2009).
Disadvantages of wind energy
Wind energy is renewable energy form with lots of advantages; some disadvantages are
also there that makes it difficult to use it on a large scale. Some of the disadvantages of wind
turbines are as follows:
1. Wind turbines cause a threat to wild life.
2. Hurricanes and tornadoes are a matter of safety concern.
3. It is not possible to set up the wind turbine in any or every area.
For example, wind energy is not creating any air or water pollution but contributing a lot to noise
pollution. This is because wind farms are situated far from the residential areas. Establishment of
wind turbines in remote areas may threat wildlife; it can harm birds flying high at the level of the
wind turbine(Hutchins, M., & Leopold, B. D., 2016). Its base is deep down from the earth
surface which effects underground habits too. Wind turbines cannot be established in low wind
areas. Tornadoes or hurricanes are harmful to the wind turbines and are of safety concerns. It can
cause damage to the labor working nearby. Before setting up the mill power curve, thrust curve,
wind speed and turbine layout should be kept in mind before setting up the whole turbine in a
locality. The high speed of wind is required to produce constant power. All this clears that it is

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impossible to build up wind plants in every location. Its disadvantages tell that it may not be
suitable for every location, but advantages conclude it to be a great source
Adoption of Wind Energy
The main concerns for adoption and investments in the renewable energy technologies
along with agreeing to the implementation policies for their support include environmental,
security and economic concerns. The primary objectives for the adoption of wind energy on the
global scale include the reduced risk from rising and volatile energy costs, energy security and
decreased carbon emissions and other pollutants. One of the primary reasons for the adoption of
wind energy worldwide is the fact that it is a highly environment-friendly source of energy. It is
also estimated that in future conventional sources of energy such as fossil fuels might run out.
The world has to look for alternate sources of energy to meet the energy demands of the future
generations (Crossley, 2000).
The most important factor towards the adoption of the Wind Energy as energy production
source as it is the cleanest forms of energy. The use of wind power as a source of power ensures
that there is no emission of carbon dioxide and other harmful gasses into the atmosphere and thus
it is safer to use as compared to fossil fuels and nuclear power stations. The main concern,
however, is to increase the output and efficiency of wind energy generation keep the costs under
check.
The wind power generation will be able to meet the increasing demand of the energy felt
worldwide. The adoption of wind power can be beneficial in enhancing the diversity in the
supply market of the energy and help in securing long-term sustainable supplies of the energy.
The emission of local and global atmospheric emissions will be reduced. Furthermore, in order to

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meet the specific demands of the energy services new commercially attractive options would be
available along with creating tremendous job opportunities. The production of renewable energy
especially from the sustainable natural sources is seen to contribute to the sustainable
development and considers the needs of the future generation. Wind power will promise out to
be the best alternative and the most suitable supplement towards the traditional energy sources
especially in the developing countries. According to the studies, wind energy has made the
considerable amount of contribution to the field of grid power installed capacity and can easily
emerge out to be one of the options for mitigating pollution (Dincer, I., 2000). Due to wind
power being environmental friendly and renewable in nature, wind energy can be converted to
electricity.
Wind Power and Augmentation
The primary challenge being faced by the urban wind energy is the lower mean speed of the
wind especially in the urban environment owning to the increased roughness in the surface of the
free streams and reduction in the heights of the wind turbines on being installed. The incoming
wind is seen to encounter higher turbulence intensity which is seen to be next to the lower mean
wind speed. However, the harvesting of the wind turbines can take place in the well sited
acceleration of the flows. This can result in over 70 percent of the increase in power.
The wind turbines and its performance can be increased using a plethora of methods.
According to Phillips (2003), a myriad of research has been performed in the field of power
augmentation of the wind turbines. Some of the famous examples of these attempts in power
augmentations are cylindrical obstruction concentrators, tip vanes on the rotor blades, diffusers
in which the rotor is located and vortex type augmentation devices. According to him, the
diffuser augmented wind turbines were considered to be the best suitable action amongst all.

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The building and maintaining of the large scale wind shrouding is seen to be expensive
however, its proper use can act as a great source of renewable energy providing an incentive for
methods that can improve the technology (Foote, 2011). According to a study by Dakeev (2014),
a cone shaped wind guide system is present in the shrouding system which results in over 60
percent of the power outcome with respect to the traditional bare wind turbine. Studies like
Dakeev (2010) and Kosasih & Tondelli (2012) suggested that the wind augmentation devices are
seen to influence the generation of power significantly.
Various research also revealed that the shroud having an angle of 30 degrees will connect to
the wind turbine and will lead to delivering of an improved power efficiency and performance as
compared to the augmentation devices installed at various angles and positions. A study
calculated that the shroud must accelerate the wind speed by 2.1 factor where the power output
will be augmented by almost three times.
It has been stated by the Betz Law that no wind turbine would be able to capture over 59.3
percent of the kinetic energy present in the wind. Around 80 percent of Betz limit is seen to be
achieved by the utility scale wind turbines at their highest peak. According to Hansen, 2000,
when the wind turbine is enclosed within the shroud, the power generation is seen to be
improved beyond the Betz limit.
The intended objective of this study is to develop an augmented wind device which can improve
the efficiency of the small-scale experimental wind turbines. Testing of the wind turbine with the
help of shroud and cone might facilitate in increasing the air flow to the turbine and thus increase
the overall efficiency. The performance of the device at various speeds and output powers will be
examined numerically and experimentally. The power output of the wind turbine will be

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compared using shrouded wind turbine using cones with the turbines which are not using the
cones.
Purpose of the study
The purpose of this study is to build and test a wind augmentation device that might improve
power generation of an experimental small-scale wind turbine. Testing of the wind turbine with
the shroud and a cone may allow the incoming airflow from the wind turbine for a greater output.
The performance of the shrouded wind turbine will be experimentally and numerically
investigated at various wind speeds as well as power output. Furthermore, the power output
parameter will be compared between shrouded wind turbine with a cone and a shrouded wind
turbine without a cone.
Significance of the study
The significance of this study was to investigate the optimal design for wind
augmentation devices to increase the power output at the outlet. Many countries are adapting
renewable energy to counteract the process of global warming. Among all the renewable
energies wind is the fastest-growing renewable energy source. Wind energy is actually a form of
solar energy. Wind energy will not produce greenhouse gas during conversion unlike with
biomass.
Definition of terms
Anemometer- An instrument for measuring the speed of the wind
Shroud- A cover around the wind tunnel.
Summary

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The purpose of this thesis is to investigate the optimal design for wind augmentation devices
to increase the power output at the outlet. Additionally, a cone is introduced into wind tunnel to
investigate if there is a significant difference when the cone had been introduced. Furthermore, I
would like investigate by changing the distance of the cone in the tunnel would increase the
power efficiency or not

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CHAPTER 2
LITERATURE REVIEW
Wind energy is the renewable form of energy which can act as an alternate or against the
fossil fuels and other energy sources. It is utilized in order to generate electricity, operate
machines, and weather forecasting etc. Various endeavors have been made in order to make the
best of the all the natural resources provided to us for generating energy. Various projects have
been performed for increasing the efficiency of the power generation and the main concern being
the increasing of throughput of the wind present in the tunnel and on concentrate fully on the
turbine and its blades. As various limitations have been seen in the efficiency of a conventional
wind turbine. Therefore, various augmentation has been performed for overcoming the
weaknesses of the wind tunnel.
A dynamic wind shroud has to be built with sensors that can help in determining the
optimal relationship between the angle wind shrouding adjusts and wind velocity owning to the
constantly changing velocities of the wind and to establish better generation of power. A critical
factor for increasing the power generation and its efficiency is to determine the optimal design of
the wind augmentation. The study aims to build and test a wind augmentation device which can
be used in improving the efficiency of the power generation in the experimental small-scale wind
turbine.
Current state of wind based power generation both in the US and global
At the end of 2013, around 39 states of US installed the 61 GW of wind energy. It is
acting as an environmentally sound energy technology, reliable and cost effective source of low-
emission power generation. The U.S. Department of Energy (DOE), offshore wind is more

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prominent in Europe and has reached 6.5GW at the end of the year 2013 and in future will
emerge in the US. The US is expanding the use of wind energy from the last several years.
Around 4.67% of the total electricity is produced by the use of wind energy. According to the
statics, the production of wind energy has been increased from 26,589 GWh to 203,453 GWh in
the last one decade. Six leading manufacturers are Vestas, Gamesa, Suzlon, Siemens, Acciona,
Nordex and GE Energy of US (Simão, H. P., Powell, W. B., Archer, C. L., & Kempton, W.,
2017). They all will exchange the knowledge regarding sitting strategies, certification of
turbines, manufacturing designs, automation process, fabrication techniques, operability and
reliability of turbines. London Array is known as the largest offshore farms in the year 2012 with
the capacity of 630 MW and then is the Gwynt y Mor with 576 MW in the year 2015.
The wind turbine when tested along with the shroud and a cone helps in allowing the
incoming airflow coming directly from the wind turbine in order to generate a greater output.
The study first discusses the various types of wind turbines present and then focuses on the
small-scale wind augmentation device for increasing the efficiency of the wind power. The wind
turbines can be divided into sub sections and can be classified on the basis of various criteria.
Classification or Types of Wind Turbines
The classification of the wind turbines is done on three main parameters. These parameters
are:
1. On the basis of orientation of axis of rotation (Crossley, 2000).
2. The component of aerodynamic forces which are responsible for its rotation (Crossley,
2000).
3. The basis of energy generation capability (small, medium or large) (Crossley, 2000).