Performance investigation and blade analysis of a small horizontal axis wind turbine utilizing whale inspired blade

Mindanao University of Science and Technology
College of Engineering and Architecture
Lapasan, Cagayan de Oro City
In Partial Fulfillment of the Requirements
In
ME Project Study II
“PERFORMANCE INVESTIGATION AND BLADE ANALYSIS OF A
SMALL HORIZONTAL AXIS WIND TURBINE UTILIZING WHALE-
INSPIRED BLADE”
Presented by:
Petronillo D. Peligro
BS Mechanical Engineering – 5
Presented to:
Dr. Jonathan C. Maglasang
Adviser, ME Project Study II
March 2016

ii
APPROVAL SHEET
In Partial Fulfillment of the Requirements for the degree of Bachelor of
Science in Mechanical Engineering, this project study entitled “Performance
Investigation and blade analysis of a small horizontal axis wind turbine utilizing
whale- inspired blade”, has been prepared and submitted by Petronillo D. Peligro is
hereby recommended for examination by the panel of assessors.
DR. JONATHAN C. MAGLASANG
Adviser
Approved in Partial Fulfillment of the requirements for the degree of Bachelor
of Science in Mechanical Engineering by the Examination Panel.
ENGR. CELIL MAY R. YLAGAN DR. LEONEL L. PABILONA
Panel Member Panel Member
ENGR. EDWARD PETER F. ROLLO ENGR. ADONIS A. CLOSAS
Panel Member Panel Member
Accepted in Partial Fulfillment of the requirements for the degree of Bachelor
of Science in Mechanical Engineering.
March 2016
ATTY. DIONEL O. ALBINA
Dean, College of Engineering and Architecture

iii
Acknowledgement
First of all we thank god for finishing our thesis project successfully, and for
giving us strength to continue our thesis project even though we encounter many
problems during the actual building of our wind turbine.
We also thank our adviser Dr. Jonathan C. Maglasang for helping us about the
simulation parameters.
We thank all our classmates who helped us during our data gathering and for
their moral supports and sharing of ideas.
I thank my parents, and my sponsor for their financial and moral support.

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Abstract
The study introduces a new blade geometry that was inspired by a hump back
whale flippers. This blade was introduced first by Dr. Frank Fish and named “whale-
inspired blade”.
Using solidworks and qblade softwares we simulate the blade geometry and
the wind turbine rotor. Whale- inspired blade shows that it increased its Cl/Cd more
than the unbumped blade’s Cl/Cd when the velocity is increasing and also when the
angle of attack is increasing. During the flow simulation the unbumped blade’s flow
lines already separates at 15o
angle of attack, as the angle of attack increases the flow
separation also increases that will cause stall and we don’t want that to happen, but
the whale- inspired blade’s flow simulation result was different as it creates swirling
vortices that re- energized the boundary layer to re attach the flow lines, that’s why
whale- inspired blade have more Cl/Cd compared to the unbumped blade when the
angle of attack is increasing.
We compare our Cl/Cd results to the previous year’s corrugated dragonfly-
wing blade and we can tell that our whale- inspired blade is much better than their
corrugated dragonfly- wing blade.

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List of Abbreviations
P= Power
𝞺= density
Cm= Average chord length
AR= Aspect ratio
AT= Planform area
Rm= mean radius
Rt= tip radius
Rb= hub radius
Zb= Blade number
Cd= Drag coefficient
CL= Lift coefficient
Fd= Drag force
FL= Lift Force
V∞= Undisturbed wind
v= Kinematic viscosity
µ= Dynamic viscosity
b= blade length

TABLE OF CONTENTS
Approval Sheet ii
Acknowledgement iii
Abstract iv
List of Abbreviations v
CHAPTER 1: INTRODUCTION
1.1 Background of the Study 1
1.1.1 Wind Turbine 1
1.1.2 Horizontal Axis Wind Turbine 1
1.1.3 Wind Turbine Blade 1
1.1.4 Humpback Whale Flippers 1
1.2 Statement of the Problem 2
1.3 Objectives 2
1.3.1 Main Objective 2
1.3.2 Specific Objective 2
1.4 Significance of the Study 2
1.5 Scope and Limitations 2
1.6 Theoretical Framework 2
1.6.1 Power that can be Extracted from Wind 2
1.6.2 Reynolds Number 3
1.6.3 Planform Area 3
1.6.4 Aspect Ratio 3
1.6.5 Solidity 3
1.6.6 Lift and Drag Coefficient 3
1.6.7 Force and Velocity Triangle 4
1.6.8 Blade Element Momentum 4
1.6.9 Mach number 4
CHAPTER 2: REVIEW OF RELATED LITERATURE
2.1 Studies on Humpback Whale Flippers 5
2.2 Studies on Whale- inspired blade 6
CHAPTER 3: METHODOLOGY
3.1 Design Requirement 7
3.2 Conceptual Design 7
3.2.1 Flow Simulation of Every Bumps 7
3.3 Preliminary Design 10
3.3.1 Flow Simulation at 8 m/s 10
3.3.2 Blade Calculation 13
3.3.3 Rotor Simulation 14
3.3.4 Calculation of Rotor Specification 15
3.4 Detailed Design 15
3.4.1 Blade and Rotor Specification 15
3.5 Gathering of Materials 16
3.6 Construction 16
3.7 Testing 17
3.7.1 Experimental Set-up Flow Chart 17
3.8 Data Analysis 17
3.9 Thesis Presentation 17

CHAPTER 4: RESULTS AND DISCUSSION
4.1 Graphs of by Bump Blade Simulation 18
4.1.1 1.5 m/s Graphs of Each Bump 18
4.1.2 1.5 m/s Blade Graph Comparison of Each Bump 22
4.1.3 8 m/s Graphs of Each Bump 22
4.1.4 8 m/s Blade Graph Comparison of Each Bump 26
4.1.5 Discussion 27
4.2 Graph of the Final Blade Simulation at Different Wind Speed 27
4.2.1 1 m/s Graph 27
4.2.2 2 m/s Graph 28
4.2.3 4 m/s Graph 28
4.2.4 8 m/s Graph 29
4.2.5 16 m/s Graph 29
4.2.6 Graph Comparison of Each Wind Speeds 30
4.2.7 Discussion 30
4.3 Theoretical and Actual 30
4.3.1 Theoretical 30
4.3.2 Actual 31
4.3.3 Theoretical vs. Actual 31
4.3.4 Discussion 32
4.4 Previous year’s Corrugated Dragonfly- wing Blade 32
Vs. This year’s Whale- inspired Blade
4.4.1 Discussion 36
4.5 Graphs of the Rotor Simulation Datas 36
4.5.1 Discussion 36
4.6 Actual Rotor Graph 37
4.6.1 Discussion 37
CHAPTER 5: CONCLUSION AND RECOMMENDATION
5.1 Conclusion 38
5.2 Recommendation 38
REFERENCES 39
APPENDIX
Appendix A: Tables 40
Appendix B: Pictures 42

Performance Investigation and Blade Analysis of a Small Horizontal Axis Wind
Turbine Utilizing Whale- Inspired Blade
1
CHAPTER 1
INTRODUCTION
1.1 Background of the study
1.1.1 Wind Turbine
Wind turbine is a device that converts kinetic energy from the wind into
electrical power. The term appears to have migrated from parallel hydroelectric
technology (rotary propeller).
1.1.2 Horizontal Axis Wind Turbine
Horizontal-axis wind turbines (HAWT) have the main rotor shaft and
electrical generator at the top of a tower, and may be pointed into or out of the wind.
Small turbines are pointed by a simple wind vane, while large turbines generally use a
wind sensor coupled with a servo motor. Most have a gearbox, which turns the slow
rotation of the blades into a quicker rotation that is more suitable to drive an electrical
generator.
1.1.3 Wind Turbine Blade
Wind turbine blades are shaped to generate the maximum power from the
wind. The blade plays a big role in a wind turbine as it increases or decreases the
efficiency of the turbine, that’s why we come up with a new blade geometry that was
invented by Doctor Frank Fish the whale- inspired blade.
1.1.4 Humpback Whale Flippers
“The humpback whale (Megaptera novaeangliae) is reported to use its
elongate pectoral flippers during swimming maneuvers. The morphology of the
flipper from a 9.02m whale was evaluated with regard to this hydrodynamic function.
The flipper had a wing- like, high aspect ratio plan form. Rounded tubercles were
regularly interspersed along the flippers leading edge. The flipper was cut into 71 2.5
cm cross sections and photographed. Except for sections near the distal tip, flipper
sections were symmetrical with no camber. Flipper sections had a blunt, rounded
leading edge and a highly tapered trailing edge. The humpback whale flipper had a
cross-sectional design typical of manufactured aerodynamic foils for lift generation.
The morphology and placement of leading edge tubercles suggest that they function
as enhanced lift devices to control flow over the flipper and maintain lift at high angle
of attack. The morphology of the humpback whale flipper suggests that it is adapted
for high maneuverability associated with the whale’s unique feeding behavior.” (Fish
and Battle 1995:51)
According to Doctor Frank Fish humpback whale flipper was observed that it
decreased drag by 32%, increased lift by 8%, and increased angle of attack by 40%
over an unbumped flipper.

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1.2 Statement of the Problem
We all know that some rural areas have no electricity. Many families in a rural
area that have no electricity are using a lamp and a candle to light their home, but
there is a danger in using lamp and candle, because it can be the cause to burn their
houses, and we don’t want that to happen. Many families also cannot afford to pay
electric bills. In Siquijor where my grandfather lives, there was no electricity there,
and even if there is electricity he still can’t afford to pay the bills as he said. It is not
good to see families that have no electricity, as students cannot study well, and they
can only do limited work. Using wind turbine it can help those families to provide
their need of electricity.
1.3 Objectives
1.3.1 Main Objectives
To design, build, and test a small horizontal axis wind turbine utilizing whale-
inspired blade
1.3.2 Specific Objective
To determine the performance using scientific calculation and experimental
method
1.4 Significance of the Study
It helps the families in the rural areas who have no electricity to have their
own electricity that will light their home.
It will show a new design of a wind turbine blade.
1.5 Scope and Limitations
The research focus on studying the performance of a whale- inspired blade and
what will be the effect when it will serve as a rotor of a small horizontal axis wind
turbine. Our thesis project will be put on the LRC building, where our actual data
gathering will be performed.
1.6 Theoretical Framework
1.6.1 Power that can be extracted from wind
Betz's law calculates the maximum power that can be extracted from the wind,
independent of the design of a wind turbine in open flow. It was published in 1919, by
the German physicist Albert Betz. The law is derived from the principles of
conservation of mass and momentum of the air stream flowing through an idealized
"actuator disk" that extracts energy from the wind stream. According to Betz's law, no
turbine can capture more than 16/27 (59.3%) of the kinetic energy in wind. The factor

3
16/27 (0.593) is known as Betz's coefficient. Practical utility-scale wind turbines
achieve at peak 75% to 80% of the Betz limit.
P= A 3
( )
1.6.2 Reynolds Number
Reynolds number is a dimensionless quantity that is used to help predict
similar flow patterns in different fluid flow situations.
v=
Re= CmV/v
1.6.3 Planform Area
The planform area of a wing is the area of a wing as if it were projected down
onto the ground below it.
AT= Cm X b
1.6.4 Aspect Ratio
Aspect Ratio is the ratio of its sizes in different dimensions. Blade’s
aspect ratio is equal to its span over the average chord length.
Cm= CN +…+ CN+1
AR= b/Cm
1.6.5 Blade Solidity
rm= √ Pitch=
Blade solidity = Cm/Pitch
1.6.6 Lift and Drag Coefficient
The lift coefficient (CL) is a dimensionless coefficient that relates the lift
generated by a lifting body to the fluid density around the body, the fluid velocity and
an associated reference area. A lifting body is a foil or a complete foil-bearing body
such as a fixed-wing aircraft. CL is a function of the angle of the body to the flow, its
Reynolds number and it’s Mach number. The lift coefficient cl refers to the dynamic
lift characteristics of a two-dimensional foil section, with the reference area replaced
by the foil chord.
CL=

4
The drag coefficient (Cd) is a dimensionless quantity that is used to quantify
the drag or resistance of an object in a fluid environment, such as air or water. It is
used in the drag equation, where a lower drag coefficient indicates the object will
have less aerodynamic or hydrodynamic drag. The drag coefficient is always
associated with a particular surface area.
The drag coefficient of any object comprises the effects of the two basic contributors
to fluid dynamic drag: skin friction and form drag. The drag coefficient of a lifting
airfoil or hydrofoil also includes the effects of lift-induced drag. The drag coefficient
of a complete structure such as an aircraft also includes the effects of interference
drag.
Cd=
1.6.7 Force and Velocity Triangle
1.6.8 Blade Element Momentum
Blade element momentum theory is a theory that combines both blade element
theory and momentum theory. It is used to calculate the local forces on a wind-turbine
blade. Blade element theory is combined with momentum theory to alleviate some of
the difficulties in calculating the induced velocities at the rotor.
1.6.9 Mach Number
Mach number is equal to the speed of the object over the speed of sound. Our
wind turbine operates at subsonic.
Mach number= ω/ speed of sound

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CHAPTER 2
REVIEW OF RELATED LITERATURE
2.1 Studies on Humpback Whale Flippers
“The advantage of the humpback-whale flipper seems to be the angle of attack
it’s capable of–the angle between the flow of water and the face of the flipper. When
the angle of attack of a whale flipper–or an airplane wing–becomes too steep, the
result is something called stall. In aviation, stall means that there isn’t enough air
flowing over the top surface of the wing. This causes a combination of increased drag
and lost lift, a potentially dangerous situation that can result in a sudden loss of
altitude. Previous experiments have shown; however, that the angle of attack of a
humpback-whale flipper can be up to 40 percent steeper than that of a smooth flipper
before stall occurs. The Harvard research validates the first controlled wind-tunnel
tests of model flippers, conducted five years ago at the U.S. Naval Academy, in
Annapolis, MD, where it was shown that stall typically occurring at a 12-degree angle
of attack is delayed until the angle reaches 18 degrees. In these tests, drag was
reduced by 32 percent and lift improved by 8 percent.” (Tyler Hamilton)
“Wind tunnel test of scale model humpback whale flippers have revealed that
the scalloped, bumpy flipper is a more efficient wing design than is currently use by
aeronautics industry on airplanes. The tests show that bump-ridged flippers do not
stall as quickly and produce more lift and less drag than comparably sized sleek
flippers. The sleek flipper performance was similar to a typical airplane wing. But the
tubercle flipper exhibited nearly 8 percent better lift properties, and withstood stall at
a 40 percent steeper wind angle. The team was particularly surprised to discover that
the flipper with tubercles produced as much as 32 percent lower drag than the sleek
flipper. This new understanding of humpback whale flipper aerodynamics has
implications for airplane wing and underwater vehicle design. Increased lift (the
upward force on an airplane wing) at higher wind angles affects how easily airplanes
take off, and helps pilots slow down during landing. Improved resistance to stall
would add a new margin of safety to aircraft flight and also make planes more
maneuverable. Drag the rearward force on an airplane wing affects how much fuel the
airplane must consume during flight. Stall occurs when the air no longer flows
smoothly over the top of the wing but separates from the top of the wing before
reaching the trailing edge. When an airplane wing stalls, it dramatically loses lift
while incurring an increase in drag. As whales move through the water, the tubercles
disrupt the line of pressure against the leading edge of the flippers. The row of
tubercles sheer the flow of water and redirect it into the scalloped valley between each
tubercle, causing swirling vortices that roll up and over the flipper to actually enhance
lift properties. Humpback whales maneuver in the water with surprising agility for 44-
foot animals, particularly when they are hunting for food. By exhaling air underwater
as they turn in a circle, the whales create a cylindrical wall of bubbles that herd small
fish inside. Then they barrel up through the middle of the “bubble net,” mouth open
wide, to scoop up their prey.” (Frank Fish, Lauren Howle, David Miklosovic and
Mark Murray)

6
“But after years of study, starting with a whale that washed up on a New
Jersey beach, Frank Fish thinks he knows their secret. The bumps cause water to flow
over the flippers more smoothly, giving the giant mammal the ability to swim tight
circles around its prey. What works in the ocean seems to work in air. Already a
flipper like prototype is generating energy on Canada's Prince Edward Island, with
twin, bumpy-edged blades knifing through the air. And this summer, an industrial fan
company plans to roll out its own whale-inspired model - moving the same amount of
air with half the usual number of blades and thus a smaller, energy-saving motor.
Some scientists were skeptical at first, but the concept now has gotten support from
independent researchers, most recently some Harvard engineers who wrote up their
findings in the respected journal Physical Review Letters. The first of these animal-
inspired ideas to reach fruition is the whale-flipper wind turbine. he scientific
literature had scant reference to the flipper bumps, called tubercles. Fish reasoned that
because the whale's flippers remained effective at a high angle, the mammal was
therefore able to maneuver in tight circles. In fact, this is how it traps its prey,
surrounding smaller fish in a "net" of bubbles that they are unwilling to cross. In
2004, along with engineers from the US Naval Academy and Duke University, Fish
published hard data: Whereas a smooth-edged flipper stalled at less than 12 degrees,
the bumpy, "scalloped" version did not stall until it was tilted more than 16 degrees -
an increase of nearly 40 percent.” (McClatchy newspapers)
2.2 Studies on Whale- Inspired Blade
“The objective of this project is thus to investigate improvement of HAWT
blade design by incorporating the bumps on humpback whales fins into blades. This
application is thought to produce more aerodynamic blades by creating turbulence in
the airflow behind each groove. This project focused on designing, simulating, and
analyzing a HAWT with whale-inspired blades to determine the differences in the
associated turbulent flow field, boundary layer attachment, and pressure gradients that
cause lift and drag compared to traditional HAWTs using computational studies. It is
shown that a whale-inspired blade offers the possibility of an improved design at
higher angles of attack. The blade is characterized by a superior lift/drag ratio due to
greater boundary layer attachment from vortices energizing the boundary layer.”
(Alex Krause and Raquel Robinson)

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CHAPTER 3
METHODOLOGY
3.1 Design Requirement
 The cut- in wind speed must be 1 m/s
 The cut- out rpm of the rotor must be 2900 rpm
 The blade must fit on the wind tunnel
3.2 Conceptual Design
Using Solidworks we simulate from 0- 7 numbers of bumps to see which of
them are the best to be put on our wind turbine rotor. We differentiate those numbers
of bumps at two wind speeds 1.5 m/s and 8 m/s. We choose 7 numbers of bumps,
because when the wind speed increases its Cl/Cd will become much better than the
other number of bumps although the unbumped blade is much better when the wind
speed is low. You can also see the graph comparison at chapter 4 results and
discussion. As you can see in the flow simulation pictures the flow lines on the
unbumped blade was already separating, while the flow lines on the 7 bump blade
was still attached. The airfoil we selected was NACA 2414, because it can operate at
low Reynolds number. The flow simulation can be seen below.
3.2.1 Flow Simulation of every bumps
Unbumped blade:

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1 Bump blade:
2 Bump blade:
3 Bump blade:

9
4 Bump blade:
5 Bump blade:
6 Bump blade:

10
7 Bump blade:
3.3 Preliminary Design
We design a new blade geometry called a whale- inspired blade. We didn’t
taper the blade, because this is just a blade for a small horizontal axis wind turbine,
and the stress on the blade can be neglected for a small wind turbine rotor. This
bumpy blade was inspired by a humpback whale flipper. We based the choosing of
number of bumps to the solidworks simulation data.
3.3.1 Flow Simulation at 8 m/s
0o
Angle of Attack:

11
5o
Angle of Attack:
10o
Angle of Attack:
15o
Angle of Attack:

12
20o
Angle of Attack:
25o
Angle of Attack:
30o
Angle of Attack:

13
35o
Angle of Attack:
40o
Angle of Attack:
3.3.2 Blade Calculation
Planform Area:
AT = Cm X b
AT = (0.089m) (0.28m) = 0.0251 m2
Blade Aspect Ratio:
AR= b/ Cm
AR= 280 mm/ 89mm = 3.146

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3.3.3 Rotor Simulation

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3.3.4 Calculation of Rotor Specification
Solidity:
rm= √
rm = √
rm = 0.247m
Pitch =
Pitch =
Pitch = 0.25866m
Solidity = 89mm/ 258.66mm
Solidity = 0.34
3.4 Detailed Design
3.4.1 Blade and Rotor Specification
Blade length = 280 mm
Average Chord Length= 89 mm
Hub Diameter= 127 mm
Aspect Ratio= 3.146
Planform Area= 0.0251 m2
Solidity= 0.34
Number of Blades= 3
Number of Bumps= 7
Rotor Diameter = 687mm
Blade Material: PLA Plastic

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3.5 Gathering of Materials
Materials used to create the rotor:
Carbon Fiber Tube
PLA Plastic
3D Printed Hub
PVC Pipe
3 8mm Bearings
3.6 Construction
We will construct our wind turbine according to the datas and specifications
that we get in each specific study. The construction of the small horizontal axis wind
turbine will be held at the top of LRC building. We made our wind turbine detachable
so that we can just easily carry it when we finish gathering the data.

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3.7 Testing
3.7.1 Experimental Set-up Flow Chart
We will put the whale- inspired blade in the wind tunnel, and see its CL/CD in
different angles of attack, after that we will use the whale- inspired blade as our wind
turbine rotor, and assemble the small horizontal axis wind turbine with a built in pitch
control. We will measure the wind speed in the area using the anemometer and we
will get the rotor rpm using the tachometer. Using the multi meter we will measure
the current and voltage of the generator and then we will use the formula P= IV to get
the power output of the generator. The Data that we gathered are all in the appendix.
3.8 Data Analysis
We analyzed the datas that we got, to see if it was correct. During the data
gathering we found some mistakes especially on the tachometer reading, because we
thought that the rpm reading of the tachometer was already the true rpm without
knowing that we still need to divide it to its blade number.
3.9 Thesis Presentation
We will present the datas, to the panels.
Wind Turbine
Wind Tunnel
Whale- Inspired
Blade
Multimeter
Generator
Anemometer and
Tachometer

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CHAPTER 4
RESULTS AND DISCUSSION
4.1 Graphs of by Bump Blade Simulations
4.1.1 1.5 m/s Graphs of each bump
Unbumped blade Graph:
1 bump blade graph:

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2 bump blade graph:
3 bump blade graph:

20
4 bump blade graph:
5 bump blade graph:

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6 bump blade graph:
7 bump blade graph:

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4.1.2 1.5 m/s Blade graph comparison of each bump
4.1.3 8 m/s Graphs of each bump
Unbumped blade graph:

23
1 bump blade graph:
2 bump blade graph:

24
3 bump blade graph:
4 bump blade graph:

25
5 bump blade graph:
6 bump blade graph:

26
7 bump blade graph:
4.1.4 8 m/s Blade Graph Comparison of Each Bump

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4.1.5 Discussion
When we observed the graph comparison of each bump at 2 different wind
speeds the 7 bump exceeds all of them at 8 m/s wind speed at an angle of attack of
10o
. Although the unbumped blade exceeds them all at 10o
angle of attack at 1.5 m/s
we still choose the 7 bump blade, because at higher angle of attack the 7 bump blade
has more Cl/Cd compare to the other choices.
4.2 Graph of the Final Blade Simulation at Different Wind Speeds
4.2.1 1 m/s Graph

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4.2.2 2 m/s Graph
4.2.3 4 m/s Graph

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4.2.4 8 m/s Graph
4.2.5 16 m/s Graph

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4.2.6 Graph Comparison of Each Wind Speeds
4.2.7 Discussion
As we you can see on the graph comparison of each wind speeds, we can
conclude that the higher the wind speed the Cl/Cd will also become higher.
4.3 Theoretical and Actual
4.3.1 Theoretical

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4.3.2 Actual
4.3.3 Theoretical vs. Actual

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4.3.4 Discussion
The actual graph for Cl/Cd ends at 20 degrees angle of attack, because the
wind tunnel’s angle of attack is limited only at 20 degrees. We can see from the graph
that the actual wind tunnel data have much higher Cl/Cd than the theoretical at 10o
angle of attack. Although there are some differences in the actual data and the
theoretical data we can still see that it was just minimal.
4.4 Previous year’s Corrugated Dragonfly-wing Blade vs. This year’s Whale-
inspired blade
Note: The black graph is the previous year’s Corrugated Dragonfly- wing
blade and the white graph is this year’s whale- inspired blade

33

34

35

36
4.4.1 Discussion
When we compare the graphs we can see that our whale- inspired blade is
much better than the previous year’s corrugated dragonfly- wing blade. Although the
wind speeds are not the same we can still conclude that this year’s whale inspired
blade is much better, because it provides more Cl/Cd.
4.5 Graphs of the Rotor Simulation datas
4.5.1 Discussion
We can see that when the wind speed increases the power generation will also
increase.

37
4.6 Actual Rotor Graph
4.6.1 Discussion
During the actual data gathering we measure the wind speed using the digital
anemometer, and use the tachometer to measure the rpm of our wind turbine. We
perform 3 trials on each day, and we perform the data gathering on Monday and
Wednesday. We can see from the graph that when the wind speed increases the rpm
of the rotor also increases.

38
CHAPTER 5
CONCLUSION AND RECOMMENDATION
5.1 Conclusion
Whale- inspired blade increases its Cl/Cd when the wind speed increases.
Among the different number of bumps that I simulate I conclude that what I read in
different journals about this whale- inspired blade was true, it really create vortices to
re-energized the boundary layer and increase its Cl/Cd. Our whale- inspired blade is
also much better than the previous year’s corrugated dragonfly- wing blade as I
compare their graph to our graph.
5.2 Recommendation
I recommend to the next batch that will continue this study to have a
simulation time span of 1 year, and add at least 8 different wind speeds in their
simulations of every bump to clearly see what the best number of bumps. Make sure
that the wind tunnel is available as early as possible. Increase the number of bumps if
possible and observed what will be the changes.

39
REFERENCES
[1] Alex Krause and Raquel Robinson . Improving Wind Turbine Efficiency through
Whales-inspired Blade Design. October 2009
[2] Hugo T. C. Pedro and Marcelo H. Kobayashi. Numerical Study of stall delay on
humpback whale flippers. January 2008
[3] O. L. Hansen. Aerodynamics of Wind Turbines Second Edition. 2008
[4] Derrick Custodio. The Effect of Humpback Whale-like Leading Edge
Protuberances on Hydrofoil Performance. December 2007
[5] D. S. Miklosovic M. M. Murray L. E. Howle F. E. Fish. Leading-edge tubercles
delay stall on humpback whale Megaptera novaeangliae flippers. MAY 2004
[6] Damià Rita Espada. AERODYNAMIC ASSESSMENT OF HUMPBACK
WHALE VENTRAL FIN SHAPES. September 2011
[7] Mukund R. Patel, Ph.D., P.E. Wind and Solar Power Systems. 1999
[8] Jhonny T. Cabasag. Design Implementation and Analysis of Corrugated
Dragonfly-wing Blade and Brimmed-diffuser Shroud to a 300-watt Type Horizontal
Axis Wind Turbine Model. March 2015
[9] Wood, D., Small Wind Turbine: Analysis, Design and Application, 2011

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APPENDIX
Appendix A: Tables
1. 1.5 m/s Cl/Cd Table of by Bump Simulation Data
Number
of
Bumps
10
degrees
15
degrees
20
degrees
25
degrees
30
degrees
35
degrees
0 3.65123 3.52174 2.49468 1.58234 1.38194 1.18326
1 2.98922 3.59928 1.91199 1.93083 1.64068 1.46615
2 3.27389 3.00962 2.75662 2.16615 1.67847 1.33706
3 3.69776 2.65195 2.80114 2.06474 1.52194 1.41748
4 3.90359 2.64957 2.67531 2.0553 1.58496 1.37262
5 3.69798 2.57833 2.65901 2.0723 1.63273 1.45417
6 3.51298 2.84031 2.65632 2.10789 1.66617 1.41269
7 3.53526 2.93375 2.69722 2.10797 1.67777 1.46454
2. 8 m/s Cl/Cd Table of by Bump Simulation Data
Number
of Bumps
10
degrees
15
degrees
20
degrees
25
degrees
30
degrees
35
degrees
0 4.5346 3.4398 2.69982 1.4769 1.2845 1.043
1 3.431 3.4216 2.16782 1.8567 1.643 1.4577
2 3.921 3.3215 2.86144 2.25321 1.69832 1.332
3 4.3315 2.98681 2.8512 2.10142 1.6372 1.385
4 4.98731 2.943 2.913 2.09836 1.677 1.413
5 4.4632 2.8236 2.896 2.10785 1.71 1.5
6 4.3213 3.143 2.7912 2.245134 1.73186 1.462
7 5.138 3.538 3.026748 2.247174 1.76 1.52
3. Final Blade Design Simulation Data, Cl/Cd Table
1 m/s 2 m/s 4 m/s 8 m/s 16 m/s
0 degrees 0.57288 -0.0215773 0.726073062 1.79544 1.9014
5 degrees 2.9475 3.851227 5.5977 6.158129 7.0853
10 degrees 3.239 3.72125 4.6597 5.1377 6.070415
15 degrees 2.6132357 3 3.3491 3.538 3.3864
20 degrees 2.58158 2.76 2.95085 3.02675 3.0852093
25 degrees 2.0375 2.152 2.210488 2.247174 2.28099215
30 degrees 1.64623 1.70234 1.734874 1.76 1.774916338
35 degrees 1.4431354 1.47652 1.499867 1.52007 1.533690411
40 degrees 1.125 1.14751 1.159957 1.168077 1.17492946

41
4. Actual Cl/Cd Data From Wind Tunnel
AoA LIFT (N) DRAG
(N)
Cl/Cd
0 1.254045 0.685065 1.830548926
2 1.42572 0.619665 2.300791557
4 1.476405 0.21909 6.73880597
6 1.60557 0.21255 7.553846154
8 1.764165 0.26487 6.660493827
10 1.836105 0.2943 6.238888889
12 2.05683 0.397305 5.176954733
14 2.21379 0.57552 3.846590909
16 2.49501 0.658905 3.786600496
18 2.66178 0.75537 3.523809524
20 2.88414 0.858375 3.36
5. Actual Rotor Data
Wind Speed RPM
Monday Trial 1 3.7 m/s 208.4667
Wednesday Trial 1 4.7m/s 261.5333
Wednesday Trial 2 4.1 m/s 244
Wednesday Trial 3 1.5 m/s 118.6667
Appendix B: Pictures
1. Wind Turbine Rotor and Blade

42
2. Data Gathering at LRC
3. Wind Tunnel Testing

43
4. Blade Painting

Performance investigation and blade analysis of a small horizontal axis wind turbine utilizing whale inspired blade

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