Investigating Optimal Design for Wind Augmentation Devices

This study investigates the optimal design for wind augmentation devices to increase power output from a wind turbine. The authors constructed a wind augmentation shroud with a galvanized steel cone at a 30-degree inlet angle and recorded outlet velocity as 3.37 m/s, compared to an inlet velocity of 2.66 m/s. The results show that the Primus AIR 40 wind turbine can operate at lower cut-in speeds (2.66 m/s) than specified by the manufacturer (3.1 m/s). The study also found an increase in power output at the outlet of the shroud, confirming the effectiveness of cone-shaped wind augmentation devices in increasing power efficiency.

Analysis of a Custom Constructed Wind Augmentation Device with 30
Degree Inlet Section to Improve Wind Power Generation
Ulan Dakeev
Assistant Professor in Industrial Management & Technology, Texas A&M University -
Kingsville
[e-mail]
Farzin Heidari
Associate Professor in Industrial Management & Technology, Texas A&M University -
Kingsville
[e-mail]
Bhavana Kashibhatla
Masters in Industrial Management & Technology, Texas A&M University - Kingsville
[e-mail]
Abstract
The purpose of this research 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 shroud is conducted to justify the means of adding a shroud around a wind
turbine to increase the speed of airflow thus generating more energy from the wind turbine.
Researchers developed a wind turbine system with shroud through which the power efficacy
can be improved and a cone to allow the incoming airflow from the wind turbine for a greater
output. Previous research revealed that a shroud with 30 degree angle connected to the wind
turbine can deliver significantly improved performance and power efficiency when compared
to other shrouded wind augmentation devices with different angles [1]. For this study the
authors constructed a large wind augmentation device in which the angle of the inlet remains
30 degrees. The device measures 100 inches in length and 50 inches outlet diameter. A cone
of 20 inches height and 10 inches diameter is inserted into the shroud. The performance of
the shrouded wind turbine is experimentally and numerically investigated at various wind
speeds as well as power output. Furthermore, the power output parameter was compared
between shrouded wind turbine with a cone and a shrouded wind turbine without a cone. The
shrouded wind turbine with a cone has demonstrated power augmentation by a factor of
about 65% compared with a wind turbine without cone, for a given turbine diameter and
wind speed.
Introduction
Utilization of wind energy dates back to 3000 years and was initially used to grind grain with
drive windmills, to propel ships and to pump water [2]. Conventional energy sources and
nonconventional energy sources are the two types of energy sources available for power
generation to the world. Because of the continuous price hikes, global warming issues and
the limited nature of the conventional energy sources like coal, petroleum, natural gas etc.
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ISBN 978-1-60643-379-9

has made the authors of this paper to suggest that nonconventional energy sources like solar
power generation, wind power generation, MHD power generation, fuel cells, thermo-electric
generation would be the best option to use as a source of power generation in future [3].
From 3.5GW in 1994 to approximately 320GW of wind power production capacity by the
end of 2013 projects that there has been a tremendous improvement in the application of
wind energy over the last two decades [1]. An important motivating factor for the authors of
this paper to use wind energy for power production is a fact that wind energy is a
nonpolluting component and environmental friendly technique used in generating power
which does not emit carbon dioxide and any other toxic gases compared to fossil fuels or
nuclear power generation [4].
It was in 1951 John Brown & co have built the first utility grid connected wind turbine. Wind
turbines have been effectively generating power by converting kinetic energy present in the
wind to mechanical energy which in turn converts in to electrical energy with the help of a
generator. In 2014, in order to encounter problems relating to the power demand with respect
to the available current supply, China has installed large scale wind farms of capacity around
114,609 MW wind energy which contributed 31% of the total wind power followed by USA,
Germany, Spain and India which produced 65,879 MW, 39,165MW, 22,987 MW, and
22,465 MW wind power respectively [5].
Literature review
Many Endeavors have been made till date in making best use of the natural resources to
generate energy and wind energy is one of them [6][7][8]. Though there are many projects which
involve power generation using wind energy the main concern is how to increase the
throughput of the wind within the tunnel and to concentrate wind on the blades of the turbine.
According to Department of Mechanical Engineering-Gurion University of the Negev, the
energy production can be improved by increasing wind velocity through the blades of the
turbine using shroud attachment in the tunnel[9]. In the present study, the researchers are
using a conical shroud in the wind tunnel because a conical member having a substantially
constantly increasing diameter in the wind flowing direction. In another embodiment, the
conical member smoothly expands in the wind flowing direction.
The efficiency of a conventional wind turbine is limited. Therefore, a wind turbine system
that consists of a shroud with a cone was developed to overcome these weaknesses. As stated
in 2014 Fifth International Conference on Intelligent Systems [10] the shroud with a cone has
the role of collecting and accelerating the approaching wind, thus improving the efficiency of
the wind turbine. In the numerical simulation, it was found that the shroud could accelerate
the approaching wind speed by a factor of 2.1 and augment the power output of a wind
turbine by 3 times [10]. However, in the shrouded wind turbine experiment, a velocity
enhancement of 1.33 times was achieved and a power output augmentation of 2 times was
demonstrated [10]. A collection-acceleration device was developed for wind, which was a
diffuser shroud equipped with brim, called wind – lens. The researchers tested two types of
hollow-structure models; a nozzle, and a diffuser type. Their experiments revealed that the
diffuser-shaped structure could accelerate the wind at the inlet [12] . Another research reported
that the power generated by an experimental small-scale wind turbine increased more than
60% when the shroud was introduced. The researchers tested and analyzed the wind
shrouding to evaluate the performance of the wind turbine at various wind velocities. The
Proceedings of The 2016 IAJC-ISAM International Conference
ISBN 978-1-60643-379-9

conclusion is given that power generation significantly increased with the wind shrouding
system [13] [14] . The researchers tested and analyzed the performance of wind shrouding with
20, 25 and 30 degree angles respectively at various wind velocities and determined that the
shroud with a 30 degree angles exhibited maximum performance at various wind velocities
[11]
Methodology
The authors of this paper have modeled and 3D printed three different custom constructed
shrouds with inlet angle 20,25,30. The shroud with 30 degree angle was selected as it deliver
significantly improved performance and power efficiency when compared to other shrouded
wind augmentation devices with different angles and a large wind augmentation device was
manufactured using galvanized steel as shown in Figure1. The device measures 60 inches in
length, 50 inches outlet diameter and 72 inches inlet diameter.
Figure1 – Wind Augmentation Device
A cone of 20 inches height and 10 inches diameter is inserted into the shroud as shown in
Figure2. The cone was shaped and constructed to allow the incoming air flow for greater
output
Proceedings of The 2016 IAJC-ISAM International Conference
ISBN 978-1-60643-379-9

Figure 2 – Wind Augmentation Device With Cone
Two optimal locations generated high wind flow at XXX University, parking lot to conduct
the experiment. The inlet and outlet wind velocities are collected using two anemometers at
inlet and outlet as shown in Figure3 for data collection.
Figure 3 – Wind Data Collection
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ISBN 978-1-60643-379-9

A total of 72 readings 36 for each inlet and outlet wind velocities are recorded at two
different locations . The theoretical power values are calculated using the formula p= 1
2 ρav3
utilizing the input and output velocities recorded individually at two different locations. The
obtained power is analysed using a statistical software called IBM SPSS Statistics. In SPSS,
t-test analysis is performed to compare the power input and power output,if there exists any
significant difference between them.
Data Analysis:
The authors of this paper used IBM SPSS statistics 22 software to conduct the statistical
analysis on the data collected at two different locations. T- test was utilized to compare the
means between the input power and output power at each location individually and determine
if there exists any significant difference between the input power and output power.
Location 1
Table 1 represents the descriptive statistics of the t-test analysis. The mean column in the
Table 1 shows that the mean value for the out power (N=36,μ=7.7225)was higher when
compared to the input power mean(N= 36, μ=3.0222), which signifies that the authors of this
research could successfully utilize the custom constructed shroud to improve the power
output from the available input wind.
Table 1 –Descriptive Statistics
Datapoint
N Mean Std.
Deviation
Std.
Error
Mean
Powe
r
Inlet
power 36 3.02 2.16 0.36
Outlet
power 36 7.72 5.59 0.93
Table 2 represents the Independent sample t-test of the analysis. Table 2 shows that
according to Levene's Test the data collected possess unequal variances as the p-value is
0.002 (<0.05) and also there exists significant differences between output and input power as
two tailed p-value in the table 2 is 0.000(<0.05). From the t-test analysis the authors of this
paper were successful in increasing the power efficiency of the wind from the available wind
at Location1.
Proceedings of The 2016 IAJC-ISAM International Conference
ISBN 978-1-60643-379-9

Table 2 – t-Test for equality of means
Levene's
Test t-test for Equality of Means
F Sig
. t df
Sig.
(2-
tailed
)
Mean
Differen
ce
Std.
Error
Differen
ce
95%
Confidence
Interval of
the
Difference
Lowe
r
Uppe
r
Powe
r
Equal
varianc
es
assume
d
10.7
4
0.0
0
-
4.71
70.0
0 0.00 -4.70 1.00 -6.69 -2.71
Equal
varianc
es not
assume
d
-
4.71
45.2
2 0.00 -4.70 1.00 -6.71 -2.69
Location 2
The descriptive statistics for location 2 is represented by Table 3. The mean section in the
table 3 reveals that the mean value for the inlet power and outlet power. Outlet power mean
value (N=36,μ=8.5463) is higher when compared to the inlet power mean value (N= 36,
μ=4.8514), which signifies that the power output can be amplified by the utilization of 30°
constum constructed shroud.
Table 3 – Statistical analysis
Datapoint N Mean Std.
Deviation
Std.
Error
Mean
Power
Inlet
power 36 4.48 4.85 0.81
Outlet
power 36 8.55 10.40 1.73
The Independent sample t-Test for location 2 is represented by Table 4. According to
Levene's Test as the p-value is 0.034 which is less than 0.05, the data collected possess
unequal variances. The two tailed p-test in the Table 4 reveals that there exists significant
differences between output and input power as two tailed p-value is 0.037(<0.05).T-test
Proceedings of The 2016 IAJC-ISAM International Conference
ISBN 978-1-60643-379-9

analysis results shows that there is a significant increase in the power efficiency of the wind
at location 2.
Table 4 – t-Test For Equality Of Means
Levene's
Test for
Equality of
Variances t-test for Equality of Means
F Sig. t df
Sig.
(2-
tailed)
Mean
Differenc
e
Std. Error
Differenc
e
95%
Confidence
Interval of the
Difference
Lower Upper
Powe
r
Equal
variance
s
assumed
4.6
8
0.0
3 -2.12 70.00 0.04 -4.06 1.91 -7.88 -0.25
Equal
variance
s not
assumed
-2.12 49.55 0.04 -4.06 1.91 -7.90 -0.22
The researchers of this paper used the Primus AIR 40 wind turbine manufactured by Primus
Wind Power company as a reference to compare the theoretical efficiency in the power they
achieved using the shroud. The technical specifications of the wind turbine provided by the
manufacturer included that the wind speed operating range of the turbine to be between 3.1 -
22 m/s. Beltz's law states that the maximum kinetic energy a wind turbine can utilize is
59.3% from the available wind[15]. One of the data values collected by the authors recorded
outlet velocity as 3.37 m/s and the inlet velocity was 2.66 m/s. This shows that the Primus
AIR 40 wind turbine if installed within the wind augmentation shroud system designed by
the authors can operate at lower cut-in speeds (2.66 m/s) than actually specified by the
manufacturer (3.1 m/s).
Conclusion
The purpose of this study was to investigate the optimal design for wind augmentation
devices to increase the power output from the outlet. Based on the wind velocity outputs
recorded from 3D printed shroud, the authors decided to construct a wind augmentation
shroud with galvanized steel of 30° inlet angle to investigate whether there is significant
difference between the power at the inlet and outlet of the shroud. The analyzed data shows
that there is increase in the power output at the outlet of the shroud. These calculations are
based on the 72 wind data points collected at two different locations in xxx university.The
calculated power increase confirms that the use of cone to direct the air flow toward the wind
turbine yields more power output.Further more, we are working on different sizes and shapes
of cone to increase the power efficiency.
Proceedings of The 2016 IAJC-ISAM International Conference
ISBN 978-1-60643-379-9

References
[1] Dakeev Ulan.2016. Comparative Study of custom-constructed Wind Augmentation
Shrouds on a small-scale Wind Turbine. ASEE 2016 (yet to be published)
[2] Jiuping Xu; Li Li, Bobo Zheng.2016. Wind energy generation technological
paradigm diffusion. Renewable and Sustainable Energy Reviews .Volume 59,
June2016, pgs 436-449.doi:10.1016/j.rser.2015.12.271
[3] JianzhouWanga, Jianming Hub , Kailiang Mac. Wind speed probability distribution
estimation and wind energy assessment. Renewable and sustainable energy reviews.
Volume 60, July 2016, pages 881-899. doi:10.1016/j.rser.2016.01.057
[4] Neeraj Gupta. 22 Jan 2016. A review on the inclusion of wind generation in power
system studies. Renewable and sustainable energy reviews. Volume 59, june2016,
pages 530-543.doi:10.1016/j.rser.2016.01.009
[5] Abhishiktha Tummalaa, Ratna Kishore Velamatia, Dipankur Kumar Sinhab, V.
Indrajac, V. Hari Krishnad. A review on small scale wind turbines.Renewable and
Sustainable energy Reviews. Volume 56, April 2016, Pages 1351-1371.
doi:10.1016/j.rser.2015.12.0
[6] Renewable Energy in North Carolina' by Diane Cherry and Shubhayu Saha, February
29 2016.https://iei.ncsu.edu/wp-content/uploads/2013/01/renewableenergync.pdf
[7] Journal Energy inventions, May 29 2009.
http://www.alternative-energy-news.info/wind-turbine-concept-jet-engines/
[8] MIT Technology Review, December 2008.
https://www.technologyreview.com/s/411274/a-design-for-cheaper-wind-power/
[9] Gurion University of the Negev, Beersheva 84120, Israel Received 23 July 1980,
Available online 5 August 2003.
[10] Su-Huei Chang, Qi-Hong Lim, Kuo-Hsin Lin,Design of a Wind Energy Capturing
Device for a Vehicle March 3 2016.
[11] Dakeev, U., Heidari ,F ,Comparative Study of custom-constructed Wind
Augmentation Shrouds on a small-scale Wind Turbine", ASEE Annual Conference
2016. (yet to be published)
[12] Ohya, Karasudari, A Shrouded Wind Turbine Generating High Output Power with
Wind-lens Technology Article by published in 'Energies 2010' ISSN: 1996-1073,
March 31, 2010.
[13] Dakeev, U., Lam, C., Pung, J.,Analysis of Wind Power Generation with Wind Guide
Attachment International Journal of Engineering Research and Innovation. ISSN:
2152-4165, Vol 7, 1, 43-47.
[14] Dakeev, U., Mazumder, Q., Yildiz, F., Baltaci, K.,Design and Development of a New
Small-Scale Wind Turbine Blades ASEE Annual Conference, 2015, Seattle.
[15] Primuswindpower.com, 2016
Proceedings of The 2016 IAJC-ISAM International Conference
ISBN 978-1-60643-379-9

Biographies:
Dr. ULAN DAKEEV is an Assistant Professor in Industrial Technology Department in the
College of Engineering, Texas A&M University - Kingsville. His areas of research include
renewable energy (wind energy), quality in higher education, motivation, and engagement of
students. Dr. Ulan Dakeev may be reached at [e-mail]
Dr. FARZIN HEIDARI currently serves as Associate Professor of industrial management
and technology at Texas A&M University, Kingsville. Dr. Heidari has 26 years of experience
in manufacturing and CAD/CAM/CNC courses. He is currently serving as the Graduate
Coordinator for the Industrial Management program. Dr. Farzin Heidari may be reached at
[e-mail]
BHAVANA KASHIBHATLA is working a Research Assistant for Industrial Management
and Technology at Texas A&M University Kingsville. She earned her B.E degree in Civil
Engineering from Jawaharlal Nehru Technological University, Hyderabad, India. Her
interests include renewable energy, sustainability Bhavana Kashibhatla can be reached at
[e-mail]
Proceedings of The 2016 IAJC-ISAM International Conference
ISBN 978-1-60643-379-9