Small Unmanned Aircraft Systems
FY13 RWDC National Aviation Challenge
Submitted by
AERONAUTICAL DOLPHINS
Name
Arada, Jill Ann
Magat, Clariza
Xiao, Stephanie
Xu, Cecilia Huixin
Aglubat, John Paul
Bigueras, Jessica
Age
Grade
17
17
17
16
18
16
11
12
11
10
12
10
E-mail
Phone Numbers (670)
jaalcada@hotmail.com
clarizamae.cookie@yahoo.com
nini_yuan1014@hotmail.com
xucecilia1@yahoo.com
johngubat@yahoo.com
jess.bigu115@gmail.com
235-3053
235-1660
785-4083
287-8908
288-2940
233-1964
OBJECTIVE FUNCTION: 232,818.02
Marianas High School
CNMI Public School System
PO Box 501370
Saipan, MP 96950
(670)664-3800
January 18, 2013
Coach: John Raulerson
Marianas High School Mathematics Department and Aviation Department Chair
237-3258 / 235-2568
raulerson28@hotmail.com
All the team members have successfully completed all the surveys.
1
Executive Summary
Introduction: Small unmanned aircraft systems (sUAS) are quickly developing in the United States and are
authorized by the Federal Aviation Administration (FAA). The option of using an unmanned aircraft to conduct
missions is a safer, faster, and easier way of completing dangerous and time-consuming tasks. The pilot of the
unmanned aircraft will be controlling the plane without the dangers of being in the air. The US Army has awarded
organizations for the use of advancing unmanned aircraft systems. In order to provide the necessary aspects of a
sUAS, our design is built around the sensor payload in order to detect the target. In creating the system that is able to
detect the target with a sensor payload and a search pattern that the aircraft will follow, detecting and identifying an
object is easily achieved.
These factors impacted our design solution to keep the system simple, yet effective in
locating anything in a designated area. Conceptual Design: In the first phase of our design, it was already
necessary for us to think outside the box. We approached the challenge with all kinds of possibilities and
brainstormed multiple design solutions in an effort to jump start our design process. First, we identified design
categories with the most cost-efficient yet exceptional performance as measured by the Objective Function (T * C).
These included: sensor payload, aircraft lift characteristics, weight, and number of aircrafts. We then used qualitative
down-select where we identified key design variables which would have the biggest impact on the efficiency of our
design. These included: aircraft layout, sensory payload and telemetry selection, UAV(s) search pattern, propulsion
system selection, ground equipment selection, and additional UAV equipment. Preliminary Design: During the
preliminary design phase, we identified selection criteria for our aircraft. We considered a wider range of wing designs
which involved variables such as aspect ratio, sweep, and taper. We also selected balsa wood for the aircraft’s
structure because it was lightweight and strong; wood is also notably easier to manipulate therefore making it easier
to repair. Concurrently, the team chose to use ceconite 101 because it’s strength in comparison to cotton and its
probable lifetime durability. To choose what kind of propulsion system our aircrafts would use, we considered the
pros and cons of three scenarios (glow fuel, 87 octane, and batteries) of fuel. We then performed high order analysis
to create the structure of our aircraft on Creo, (put more stuff on cognitive thinking.) Detailed Design: Our final
design included a glider inspired fuselage with a 1800 Watt electric brushless dc motor. The wing uses a single airfoil,
the NACA 4415, for high lift coefficient(1.866) in low Reynolds number flight and an average thickness of 14.994
percent and a camber of 3.974 to compensate for the storage, and extension of flaperons, which act as ailerons, flaps
and spoilers for the aircraft. Our wing has an aspect ratio of 11.3, a taper ratio of .57, a sweep of 4.14 degrees and
has a planform area of 414 square inches without the flaperons and 538 square inches with the flaperons fully
extended with a chord increase of 2 inches. We are using a high wing design and have a wing dihedral of 5 degrees
to keep the aircraft straight and stable in flight. We are using winglets to improve our take off and climb time as well
as reduce lift-induced drag and the effect of wingtip vortices. We have a wing incidence of 1.56 degrees because our
cruise speed will 73.42 and that alpha provides us with the lift coefficient that creates just enough lift to support the
weight of our aircraft, 22.53 pounds of lift. Our aircraft also features airbrakes on top of its fuselage to help the aircraft
create drag when it is slowing down to reduce the amount of lateral coverage lost in the detection phase where we
zoom in on a possible target for confirmation for 5 seconds. Our four aircraft were able to search the entire 2 mile
radius search area in Philmont Ranch, New Mexico in 17 minutes with each still having about 50% of their battery life
to spare. We achieved a nominal Objective Function value of 240,602.21, traveled a combined total of 69.745 miles
for all four aircraft without recharging, going at a cruise speed of 73.42 mph and making a combined total of 72 turns
in the process.
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Table of Contents
1. Team Engagement
1.1 Team Formation and Project Operation
06
1.2 Acquiring and Engaging Mentors
08
1.3 State the Project Goal
09
1.4 Tool Set-up / Learning / Validation
10
1.5 Impact on STEM
10
2. Document the System Design
2.1 Conceptual, Preliminary, and Detailed Design
2.1.1 Conceptual Design (Many Solution Candidates)
12
2.1.2 Preliminary Design (Few Solution Candidates)
14
2.1.3 Detailed Design (One Solution Candidate Refined)
20
2.1.4 Describe lessons learned
25
2.1.5 Describe project plan updates and modifications
27
2.2 Detail the Aerodynamic Characterization
2.2.1 AeroData Characterization
29
2.2.2 Airfoil Validation
29
2.3 Selection of System Components
2.3.1 Propulsion System
31
2.3.2 Sensor Payload Selection
32
2.3.3 Ground Station Equipment Selection
35
2.3.4 Additional UAV/UAS Equipment
35
3
2.4 Aircraft Geometric Details
2.4.1 Wing Configuration
36
2.4.2 Tail Configuration
37
2.4.3 Fuselage
38
2.5 System and Operational Considerations
41
2.6 Component and Complete Flight Vehicle Weight and Balance
42
2.7 Maneuver Analysis
45
2.8 CAD Models
47
2.9 Three View of Final Design
48
3. Document the Mission Plan
3.1 Search Pattern
50
3.2 Camera Footprint
51
3.3 System Detection and Identification
53
3.4 Example Mission
54
3.5 Mission Time and Resource Requirements
56
4. Document the Business Case
4.1 Identify targeted commercial applications
59
4.2 Amortized System Costs
61
4.2.1 Initial Costs
61
4.2.2 Direct Operational Cost per Mission
64
4.2.3 Amortization
65
4.3 Market Assessment
66
4
4.4 Cost / Benefits Analysis and Justification
5
67
1. Team Engagement
1.1
Team Formation and Project Operation
We established leadership positions in all the appropriate areas which was required and
listed as followed: project management, science, engineering, mathematics, marketing and
communications. Jill was the project manager and she was in charge of communications,
Clariza was the lead design engineer, John Paul was the lead technical engineer, Stephanie
was the lead mathematician, Cecilia was in charge of science and Jessica headed the
marketing department. Our strategy was to collaborate and share ideas in ways that
maximized our abilities. The team met up frequently to work on the project and
communication among each individual was extremely important. We collaborated with many
great individuals in our society which expanded our knowledge in all areas. The skillset of
each member was vital in completing all aspects of the challenge.
Being 14 hours ahead of the rest of the states, we had to calculate the time when
webinars would take place. We usually met as early as five o’clock in the morning just to
watch the webinars.
Project plan versus calendar dates:
6
The project manager (Jill) of the team organized the team’s schedule to make sure that
each member was focused on their task. She was able to analyze her teammate’s hectic
schedules, thus; implementing special accommodations when needed. In addition, she
remained attentive to the advice given to her by the mentors as well as the job of relaying
information to her team. Furthermore, during last year’s competition, she proved that she
was efficient in gathering information from the mentors.
The lead design engineer (Clariza) was exceptionally creative and introduced ideas that
were beneficial to the team. She also led the team in research and allowed us to acquire the
strongest, lightest and most cost efficient materials in respect to the aircraft’s mission. She
was more than capable of the job because she worked on last year’s challenge. Clariza also
assisted Jessica with important marketing decisions.
Working as the lead technical engineer, John Paul was in charge of the software.
Notwithstanding, being recently introduced to the software, he was able to familiarize
himself with the state of the art technology in a short amount of time. He has proven to be
very skillful and technologically advanced and therefore was deemed qualified for the title of
lead technical engineer. His tenacity and patience toward the software was also
commendable.
New to the competition, Stephanie worked diligently to solve mathematical problems.
She is currently taking AP calculus and excelling. She was the lead mathematician and she
guided the team throughout all mathematical challenges. Stephanie familiarized herself with
the problems that she faced and explained in detail, all her findings to the rest of the team.
Acquiring the team’s leadership in science, Cecilia is new to the Real World Design
Challenge. Currently, she is taking an AP Science course. Cecilia has shown great
enthusiasm since her inception into the Real World Design Challenge. With her skill sets, we
are able to attain a better understanding of scientific concepts needed to have a true
understanding of the challenge.
The marketing lead (Jessica) possessed exceptional marketing and business skills. Her
special skills help us maximize the cost to business aspect of the aircraft and mission. She
also identified all the pros and cons of each design possibility, giving her team mates
essential input on how the aircraft could be designed and advertised. Furthermore, Jessica’s
7
marketing and business experience proved to be a valuable asset to one of the two major
components of the challenge.
Name
Jill Ann Arada
THE TEAM
Title
Project Manger
Clariza Magat
Lead Design Engineer
John Paul Aglubat
Lead Technical Engineer
Stephanie Xiao
Mathematician
Cecilia Xu
Lead Mission Planner
Jessica Bigueras
Marketing Lead
Responsibility
Distributing jobs, managing
team schedules, and
organizing information.
Analyzing materials and
presenting the price, pros,
and cons, and leads
research
Conducts analysis with
MathCad, Creo, and FloEFD
softwares.
Solves mathematical
obstacles the team faces.
Creates possible mission
plans with effective
outcomes and is in charge of
the search pattern.
Researches about the
possibilities of what the UAV
is capable of and applies it to
our aircraft as well as writing
about it in the marketing
section.
1.2 Acquiring and Engaging Mentor
Throughout the challenge, we faced certain obstacles that required additional guidance.
During the process of identifying mentors, we looked through the list that RWDC had provided.
Although we already had one mentor that we met from last year’s challenge, we needed to
increase our knowledge base to additional professions, which required more mentors.
Therefore, we selected additional mentors from the list by looking at their title and professional
background. We also considered the fact that the individuals on the list would be obligated to
mentor other teams, therefore; we expedited our requests as soon as possible. We maintained
a dialog with the mentors that replied to our email and sent back helpful information. Our media
communication of choice was email.
We contacted several individuals from the mentor list and received a few replies. We kept in
mind that mentors may be busy and respected their decision in accepting or denying our
8
request. We worked with Rene Buendia, David Billingsley, Jeff Duvan, and Manoj
Rahematpura. Mr. Buendia, Mr. Billingsley, and Mr. Duvan were all new mentors. We worked
with Mr. Rahematpura in the previous year.
Aside from mentors on the list, we also collaborated with a few individuals from our school
and community. We had Jonathan Liwag to help us with technical issues which was still our
Achilles’ heel and Emory Frink who provided us with mentoring on aircraft physics.
We looked over UAV websites and found the AeroVironment, Inc. website. We talked to
Carly Garrison through email and although she is not on the mentor list, she agreed to become
our mentor. She worked in the business development sector of the company and mentored us
in the marketing section of the challenge, learning a great deal from her. We tried to convince
her to become an official mentor for RWDC.
Throughout the challenge, we met new people that enriched our knowledge. Learning from
many great individuals helped us greatly with the understanding of the challenge process.
Mentors
Name
Email
Company Name
Manoj Rahematpura
manoj.rahematpura@pw.utc.com
Pratt & Whitney
Carly Garrison
garrison@avinc.com
Aerovironment, Inc.
David Billingsley
david.billingsley@gmail.com
AAI Corporation
Rene Buendia
rene.buendia@faa.gov
FAA
Jeff Duvan
jeff.duvan@faa.gov
FAA
Emory Frink
em.frink@gmail.com
Retired Pilot
1.3 State the Project Goal
Our team’s project goal was to design a small unmanned aircraft system, which includes
one or more fixed-wing UAV’s, and to develop a business plan for our design. We were given a
mission scenario to search for a missing, injured, and immobilized child with a blue jacket during
the day at the Philmont Ranch in a designated 2-mile radius circular search area.
Fortunately, this parts of the challenge statement create a strong relationship with the
project goal. The objective function includes the total time required to complete the mission and
the overall cost of the system while completing the mission fifty times. The objective function
9
represents an enormous part of our efforts in completing the challenge because it is derived
from our unique ideas and designs. Our design variables were also related to the project goal
and we strived to create an optimal design in respect to cost. We wanted to minimize the cost of
the UAVs and the ground-based components and complete the mission by rescuing the injured
child as fast as possible.
Our objective function, design variables, and project goal formed a clear relationship with
our design solution. We started with the project goal and collaborated to create new ideas on
possible designs. Our objective function was then brought forth after following through with the
cost of the overall mission. It represents a great deal of our efforts and contributes greatly to
our design solutions.
1.4 Tool Set-up / Learning / Validation
The installation of Creo and Mathcad were relatively straightforward. Thanks to the tutorial
videos on the PTC website which eliminated all of the roadblocks for the team. Therefore, we
were able to figure everything out, without going through the trial and error process. The only
delay was in the license files. John Paul tried utilizing the team’s old license codes. The license
codes allowed us to install the software. However, John Paul couldn’t use the software until he
had access to the updated license codes, which he finally received the day after installing the
software. While John Paul has used other modeling software before like blender, Creo was not
as user-friendly as he anticipated. However the tutorial videos and the webinar presentations
proved to be extremely helpful. And the linking of the software to OpenVSP made it much easier
as OpenVSP is much more user-friendly and quicker to use. We sent a request for the FloEFD
product codes a few days after the national challenge came out. We waited for around three
weeks until we received the codes. We emailed RWDC support several times and finally
received the codes after a long time. John Paul then proceeded to input the codes into FloEFD,
but a message box kept appearing that it has not received the license for the feature efdpro.
1.5 Impact on Stem
By participating in this challenge, each member of the team was enriched with knowledge and it
influenced their perspectives on science, technology, engineering, and mathematics as well as
their potential career paths.
10
Jill: “It is the second time I have participated in the Real World Design Challenge and I never
get tired of learning new things from new people. This challenge helped me perceive STEM as
extremely interesting. It made me think about my future and what I wanted to do in life.
Engineering is quite a challenge and I love to take on challenges. The challenge impacted
STEM interests in my school by giving an opportunity for students to solve real world problems
in real world situations.”
Clariza: “Before the Real World Design Challenge, I’ve always known that I would be a science
major. On the other hand, after participating in the challenge for two consecutive years, there
are so many more career paths I considered. I’ve always contemplated about taking a career
path into engineering and technology, but I’ve never really taken it into serious consideration
until joining RWDC. I still find it exciting to acquire new information and take on various
challenges on a daily basis.”
Cecilia: “This is the first time that I have participated in the Real World Design Challenge and it
is quite a challenge. It’s difficult but at the same time, fun. I have learned a lot of things about
aircraft and cameras. Also, I have never participated in a big project which deals with science.
This challenge encouraged me to learn more about engineering and technology. It also helps
me focus more on science because I have yet to explore much of it. With the current challenge,
it also lets me understand many situations that needed modern science technology.”
Jessica: “This is also my first time to participate in the Real World Design Challenge. I find it
very challenging, but interesting. Participating in this challenge allows me to learn more about
STEM and how to apply them in real life situations. This makes me think about my future a lot. I
never knew the basic structures of an aircraft until I started my own self-studying requirements
for the challenge. Learning from my teachers, teammates, and mentors, made me aware of
what else is out there.”
Stephanie: “I am new to the Real World Design Challenge and it’s really cool to use my
knowledge of mathematics to solve the problems of the real world. For example, when I was
challenged by the first problem which I never solved before, I felt excited during the process of
finding a solution. Throughout the challenge, I have filled my brain with knowledge and realized
that this is what I want to do. The challenge impacted my STEM interests by using what we
learned in class to solve real world problems.”
11
John Paul: “I’ve always been interested in engineering and science. I’ve always done research
on possible inventions I may be able to try in the future with professional technology. The Real
World Design Challenge got my interest because I want to get the feel of using applied science
now. I’ve been doing research on aviation designs for a while. I like a challenge and feel that it’s
time to use my knowledge for something a little more productive than just more research.”
2. Document the System Design
2.1 Conceptual, Preliminary, and Detailed Design
2.1.1 Conceptual Design (Many Solution Candidates)
Conceptual
Design
- Brainstorm solutions
- Consider all aspects
of payload
components
- Select design
candidates for
further analysis
In the beginning of the challenge, we collaborated and came up with many ideas. For
our conceptual design, we considered all our possible options.
The first topic we discussed was regarding the sensory payloads. We were looking for a
camera that was lightweight, efficient, good quality, provided sufficient rolling limits, a
commendable optical zoom, and is cost efficient. We considered all the choices from the
catalog that RWDC offered.
12
Picking from the catalogs, we had choices of propulsion systems that would either need
fuel or batteries. We needed a propulsion system that would generate enough thrust for
our aircraft to stay in flight at a constant velocity. We considered all the choices from the
catalog and narrowed it down to the best choices for the mission. We considered all the
choices from the RWDC catalog and came up with a conclusion that our propulsion
system should be lightweight, should be able to generate enough thrust for our aircraft to
stay in flight at a constant velocity, and of course, cost efficient.
Propulsion System Choices
GL-6
Specifications
GL-12
GL-25
GA-55
GA-
E-6
E-20
E-70
110
Weight
0.5 lbs
1.4 lbs
2.1 lbs.
4.9 lbs
6.9 lbs
0.43 lbs.
1.1 lbs.
3.5 lbs.
Generated Thrust
2.1 lbs
5.1 lbs
13 lbs
33 lbs
56 lbs
2.0 lbs
13 lbs
35 lbs
Cost
$109.99
$499
$545
$595
$795
$170
$295
$559
80%
80%
85%
85%
80%
80%
85%
Fuel
Fuel
Fuel
Fuel
Batteries
Batteries
Batteries
In-Flight Propeller 75%
Efficiency
Powered by
Fuel
We also considered the general shape of our aircraft to be sleek and lightweight.
 Sleek, lightweight
 Wings are able to generate lots of lift
13
 Many different tail shapes and sizes considered
The overall conceptual design of our aircraft included a large wingspan with a winglet on
each wing. The size of our aircraft would be quite small, about three feet in length. Our
components would be lined up in the fuselage where the sensory payload would be near
the center of gravity. We also wanted the general components of our aircraft to be as
close as possible to reduce the size of our UAV. For our wings, we considered high wing
regarding lift and low wing regarding speed. We then planned to include winglets into our
design. Winglets reduce the erraticness of wingtip vortices, improve energy efficiency
and reduce our needed take off speed. For our ground station equipment we planned to
have one of each component/workstation since we plan to use only one aircraft. .
2.1.2 Preliminary Design
- Explore design space
Preliminary Design
- Identify merits of each
candidate
- Identify changes
needed to be made
14
- Downselect
candidates based on
merit
The team started meticulously planning on the aircraft’s components as soon as
the challenge was released. To begin the process of finding the most favorable
components, we made sure to carefully read the catalog, beginning with the sensor
payloads. To narrow our selection, we focused on the X1000, X3000, and X4000. The
choices were simplified by looking for sensor payloads that had a competitive price, low
power draw, and lighter weight with accommodations of wider rolling angles and a
reasonable zoom. The X1000 was one of the contenders because of its feasible price,
light weight, and low power draw. On the other hand, it lacked the ability to zoom. In
competition, the X3000 claimed our attention because of its better rolling angles,
reasonable telephoto, and reasonable weight. However, it had the highest power draw.
Conversely, the X4000 was desirable because it included a zoom of 16x telephoto and
in comparison to the X3000 had a lower power draw and wider rolling angles. Yet, the
price of the X4000 was more expensive and it was the heaviest amongst all the sensor
payloads considered. Initially, we chose to accommodate the aircraft two X1000s
because of its price, however it lacked an appropriate zoom. Therefore, we narrowed
down our choices to the X3000 and the X4000.
After the conclusion of the sensor payloads, we discussed the propulsion system.
We focused on a propulsion system that proposed an agreeable price and minimum
weight, with sufficient power for our aircraft. In addition, it had to be environmentally
friendly. Nonetheless, we simplified our choices to the GA-55, GA-110, and E-20. Our
choices started off with the GA-55 and the GA-110, considering these were the units
with enough thrust capable of providing enough power for our aircraft. As well as
adequate power, both these choices were very heavy and expensive. The E-20, on the
other hand, runs on electricity and would require batteries. Although we would need to
find a reliable battery power, it is the lightest and cheapest propulsion system amongst
our choices.
In regards to the ground stations, we decided to have one emergency pilot, in
case of any accidents, a main pilot maneuvering the aircraft. We also chose to have a
payload operator, as well as one maintenance representative for mechanical issues.
15
Preliminary design drawings:
A. Our first design
B. Increasing the diameter
16
C. Sensor payload arrangement
D. Decreased our wetted area
17
E. Rearranging our components
F. Decreasing the radius of the fuselage
Descriptions
A. Our first design
The picture shows our very first design for our
UAV. We tried to move the camera from the wing
box to the aft fuselage but in reference to the
18
picture above, the camera was too bulky to fit in
the aft fuselage. Each square on the graph paper
represents one square inch (Top View)
B. Increasing diameter
We increased the diameter of the fuselage from
1.5 to 2.6 inches and moved the camera from the
wing box to the aft fuselage. Also, we found out
from the webinar on Nov. 27 that if our propeller
was too big, then our power plant selection was
also too big. (Side View)
c. Sensor payload arrangement
We attached the wings to the top of the fuselage.
We switched from the X4000 to the X3000
because it was not as bulky as the X4000 and it
was also much lighter. Fortunately, the downsides
of the X3000 were acceptable; therefore, we
decided to stick with it.
D. Decreased wetted area
We then realized that we had extra volume in the
back that we didn’t use. Thus, we moved the
camera from the aft fuselage to underneath the
wing box and eliminated the extra volume that
was not being utilized in the aft fuselage area. This
trimming process decreased our wetted area.
E. Rearranging components
In the picture above, we moved the camera from
underneath the wing box to directly aft of the nose
because the camera was the bulkiest item and we
wanted to install the items from largest to
smallest. Thus, we decreased the radius of the
aircraft once we pass the X3000. This deduction
helped in the efficiency of the aircraft by further
reducing the wetted area. We also moved the ram
air turbine from the wing area to directly behind
the propellers.
F. Decreasing the radius of the fuselage
In the picture above, we are decreasing the radius
of the fuselage as we pass the X3000 until we get
to the attachment of the boom. We made it more
streamline and lighter, by again reducing the
wetted area. We brought the wings down to the
center fuselage for attachment at the same
waterline and fuselage stations of the CD and VD
units.
19
2.1.3 Detailed Design
- Analyze candidates to
improve aircraft
Detailed Design
- Conduct high-order analysis
(airfoil, wing, tail, etc.)
In reference the fuselage, our detail design rearranged the aircraft components from
greatest volume to the least volume. The purpose behind this change was to decrease our
wetted area. By decreasing our wetted area, it made our aircraft more efficient by reducing its
weight. Furthermore, once the components were arranged in descending order, we realized that
a large portion of the aircraft was not being utilized. Therefore, we started eliminating the
excess. After the excess was trimmed off, we simply created a leaner more efficient aircraft.
The airfoil we chose was the NACA 4415. We have tried several airfoil designs, but the
NACA 4415 came out to be the best. The NACA 4415 airfoil showed pretty good results from
javafoil testing as compared to the other airfoils we considered (NACA 0010 and the SD 7032).
It was also an airfoil design that made sense. Short near flat bottom to let more air pass through
and increase air pressure below to create lift, aerodynamically curved top to reduce lift-induceddrag, but also slow air particle moving across the top to reduce upper air pressure and create
lift.
“This classic airfoil has been analyzed with JavaFoil and compared against wind tunnel tests
performed in the Laminar Wind Tunnel at Stuttgart, The data presented in NACA Report No.
20
824 and results produced by XFLR5, an implementation of the XFOIL algorithms. The airfoil
coordinates were created with JavaFoil, using the standard number of 61 points.
The maximum lift coefficient is over-predicted by both numerical methods (JavaFoil, XFLR5).
The lift gradient is (dCl/dalfa) is also overpredicted because no boundary layer displacement
effects are modeled. While these are modeled in XFLR5, the deviation from the experimental
values is also rather large. The drag coefficient lies close to the experimental values but is
considerably higher than the XFLR5 prediction. At lower lift coefficients, the lower surface
becomes
fully
turbulent
and
the
drag
is
predicted
too
high.”
(http://www.mh-
aerotools.de/airfoils/jf_validation.htm)
We also added winglets to reduce the needed takeoff speed and improve our
climb rate and our energy efficiency allowing the aircraft to last on longer missions. Our
high aspect ratio wings allow for high lift while sacrificing maneuverability because
maneuverability is not an all-too-important factor so long as our aircraft is capable of
making its spiral search turns. We added dihedral to prevent side-slip angles and have
more lateral balance and stability giving us more control of our turns. In addition to our
aircraft design, we decided to include flaperons. Flaperons will allow us to roll the
aircraft, take off at a slower speed, land at a slower speed, fly at a slower speed and
maintain the same altitude. It also prevents our aircraft from flipping over in flight.
Our wing’s sweep is designed to flatten the back edge of the wing to compensate for the
flaperons, which we use for slowing down when we spot a potential candidate for
21
confirmation. Our horizontal tail’s anhedral balances out the lift of the wing which occurs
mostly near the nose to balance the fore and aft of the aircraft. Its sweep is similar in
purpose to the wing’s, which is to flatten its back edge to compensate for elevators. The
design behind our vertical is to keep the aft of the aircraft laterally stable as well as keep
it at the aft most end without its root trailing end passing the length of the fuselage.
Regarding efficiency, we further recognized the need to multi-function
components to enhance efficiency. For example, we decided to move the antennas from
the (Bottom Fuselage) Video Data link and the Command Data link and move them to
the right and left wing tips respectively. Due, to this placement, our antennas became
multi-functional because they now serve as followed: structural component for the
winglets, counter torque for the propeller and finally communication between the base
and the aircraft. Therefore, instead of only serving one purpose, the antennas have been
made multi-function to serve three purposes. Also, the drag component of the antennas
will be virtually eliminated.
In regards to the equipment selected, we decided on both the X3000 for its
reasonable price and telescopic capabilities and chose E-20 because it was light and
cost effective as well as powerful enough to power our aircraft. The selection of a motor
expanded the decision to be environmentally friendly because it lacked any harmful
byproducts. Concurrently, the team agreed to select one component from both the
sensor payload and propulsion system catalog. Both were able to function adequately
and perform efficiently without any extra assistance from a second component. The
selection of only one component for each equipment concluded in a cheaper and lighter
aircraft.
In order to charge our aircraft’s batteries, we needed to decide on a generator
that we would use. We chose the magnetic generator. Magnetic generators make use of
magnets in order to generate energy. It has the capability to generate enough power for
homes. If it can generate enough power for houses, it can surely charge our aircraft’s
batteries. Besides from performing the main goal, magnetic generators help save Mother
Earth. In the manufacturing of magnetic generators, no toxic materials are used. The
magnetic generator makes use of the energy it produces on its own through the motion it
yields, thus concluding in an environmentally friendly and efficient generator amongst
others.
The material used on the aircraft will be both wood and fabric. The wood will be
for structure; concurrently the fabric will be used as the aircraft covering. The fabric
22
chosen for our aircraft is ceconite 101. Ceconite is exceptional for our aircraft and in
comparison to cotton it is far stronger and durable. Conversely, ceconite 101 has
probable lifetime durability. Due to its probable duration capabilities, we are not required
to annually change the fabric covering making it more efficient and less expensive to
use. In regards to the wood, the aircraft’s structure will be composed of balsa wood.
Balsa wood is a fast-growing, organic product, therefore making it environmentally
friendly. Balsa wood is notably lighter and stronger than its competitor. There are also
organizations that make sure balsa trees are being regrown to replace the old ones,
because of this we are not losing any balsa trees and harming the environment. Balsa
wood is also easily repaired and easily manipulated to fit any specific preference. Both
Ceconite 101 and balsa wood will equally sustain our plane due to its durability and
strength. Additionally, the aircraft’s light weight and affordability make it feasible to
customers. In regards to the search route, the team decided upon a spiral search
pattern. The team continuously debated upon both the spiral and sector search.
However, unlike the sector search, the spiral did not go beyond the designated search
area, saving much time and reducing personnel cost. Thus, the conclusion of the spiral
search route.
Side view of our final design of the Dragonfly
Regarding the way the search area will be surveyed, we decided to use four
identical aircrafts. We were caught up with the option to have only one aircraft versus
having two aircrafts versus having four aircrafts. We considered the time and cost
23
needed for each separate operation. The mission is to find the injured and immobilized
child as soon as possible to delay further harm and the less time spent the better.
It would take about 64 minutes for one aircraft to complete the designated search area using the
spiral search pattern.
It would take about 31 minutes for two aircraft to complete the search area using the sector
track search pattern.
24
It would take about 15 minutes for four aircrafts to complete the search area using the sector
track search pattern.
2.1.4 Describe lessons learned
We learned many valuable lessons from the challenge. Our knowledge in
aviation has greatly expanded. Aside from the vast knowledge we have learned, each
member of the team also garnered skills like leadership and communication which each
of us will use in our futures.
Regarding our aircraft design, we learned that by using more aircraft to search
the same area, the weight could be reduced by elimination of two batteries. This
reduction will remove 2.2 pounds from each aircraft. Thus, the reduction in weight will
make each aircraft more efficient. We also learned that it is better to move the wing and
rearrange the components in order to maintain CG limits, over adding ballasts. Ballasts
would allow us to maintain CG limits, but we would have to take on extra weight, which
would take away from the efficiency of the aircrafts. Also, slowing the aircraft to the rate
needed for turns and detection could be achieved by increasing the angle of attack while
25
using the flaperons as spoilers. We then removed the micro alternators because it was
proven that the batteries provided more than enough power for the motor and
components.
Creating a flight chart provided an excellent means of tracking important
information such as: time (minutes, seconds and fractions of a second), distance (the
length of the arc, ¼ turn, mid turn, the percent of completion of each entity, power
consumption, and total power needed for each sector including the power needed to run
the components. The search pattern is identified on this document as well as velocity
changes for detection and turn sections. Although we are limited to 80 pages and could
not include the whole charts, it helped us greatly.
We were able to understand that the aircraft becomes more efficient when
components are able to multi task such as the antennas and the flapperons. We also
recognize that sometimes you have to move structure components to achieve the proper
weight and balance. Furthermore, we had to relocate the wings in order to achieve a
proper CG limit on the aircraft. After, obtaining, the proper CG limits we recognize the
importance of establishing a datum line as well as a left and right butt-lines.
Furthermore, we needed to establish a moment between to two antennas on opposite
sides of the wing.
During the live webinar broadcasted on November 28, 2012 they discussed that
propeller would be at a disadvantage if we shortened it to an equal ratio of the
propulsion system. Hence, both the propeller and the propulsion system were too big for
the aircraft. We also learn that the propeller for a motor has a larger diameter than a
propeller from an engine. Therefore, we had to select another propulsion system that
would be an adequate for the size for our aircraft. Also, it is very important to participate
in webinars. We noticed that in the state challenge, some designs had landing gear
attached. Furthermore, we were informed that landing gear was not needed because the
aircraft would be catapulted in the air. Participating in webinars give us vital information
that helped us throughout the challenge.
We were able to recognize that the focal length was the altitude of an isosceles
triangle that is proportional to the altitude of the aircraft over the ground. And the base of
the focal triangle is proportion to the lateral, forward and aft coverage distance on the
ground.
26
Additionally, math has played a major role in the design of our aircraft. There
were various formulas to be learned that was used and applied to figure out the aircraft’s
measurements.
Regarding the design of our aircraft, we have learned many things. We found out
that our aircraft will need fewer batteries because the power densities of the aircraft’s
batteries are enough to support the time allotted. With this, we then learned that our
aircraft will be able to climb faster because it will be lighter because of the reduced
weight of the batteries. We also needed to increase the angle of attack and use the
flaperons to create enough drag to slow the aircraft down to five miles per second. We
then decided to add a speed brake to justify slowing down at five miles per seconds
when our aircraft detects an object. In regards to flight detection, we learned that our
aircraft will not have enough lateral distance covered to reach the outer limits of the
circle if we didn’t start in the center of the search area. Therefore, we decided to work
our way outward. As we continued our design processes, we soon learned that our
flaperons will have three functions: ailerons, flaps, and spoilers. The team tested the
objective function of having one, two, and four aircrafts. We then learned that having four
aircrafts created a smaller objective function than the other two choices because of the
reduced time.
Essentially, we also learned that cooperation and teamwork is needed to
succeed in challenges like these. Like they say, two brains are better than one and six
brains working together is fantastic.
2.1.5 Describe project plan updates and modifications
o
Flaperons will be installed under the wings of the airplanes. Adding flaperons will
prevent the aircraft from rolling over. Flaperons will also enable the aircraft to
maintain altitude when the velocity is decrease. Other positive of the flapperons
will be their multi-functional roll as flaps and ailerons. Furthermore, these devises
will allow the aircraft to take off at a slower speed and land at a slower speed. It
will also allow us to decrease our stall speed.
o
We will not install landing gear because the aircraft will be catapulted in the air
during takeoff and caught by a restraining net during landing. We learned of
these methods during the December Webinar
o
We incorporate wing twist to stall the inboard wings before the outboard wings.
This action will allow the pilot control of the aircraft in case of a stall.
27
Furthermore, if the inboard wing is stalling, then you will still have lift on the
outboard wings.
o
Dihedral will allow the aircraft to have lateral stability during rolls. Our aircraft has
a five degree dihedral
o
We have winglets installed to decease the takeoff roll, decease induce drag and
increase the laminated air flow over the wings. Therefore, the winglets, make the
aircraft more efficient
o
We will be using a magnetic generator, which will be recharging the batteries with
free energy.
o
We tapered the wings to counteract the effects of induce drag. Induce drag is
created from high pressure air that is created beneath the wings, moves to the
low pressure air above the wings. The result of this action creates a push down
force on the top of the wings. This push down force is called induce drag. By
tapering the wings, we expose less wing area to this push down force and
thereby, reduce the effects of induce drag.
28
2.2 Detail the Aerodynamic Characterization
2.2.1 AeroData Characterization
This shows the lift and drag coefficients for our aircraft from javafoil.
2.2.2 Airfoil Validation
It was difficult to complete this section due to the fact that it took an unprecedented amount
of time to receive the codes for FloEFD. When we finally received said codes, John Paul
received an error indicating the codes were either invalid or the license server could not be
found. Because of technical difficulties we had to improvise with the javafoil results and with
the lift coefficients and alpha calculations from javafoil we were able to calculate using the
29
lift equation the most suitable angle of attack for our cruise speed as shown in the
screenshot below.
30
2.3 Selection of the System Components
2.3.1 Propulsion System
The E-20, a Brushless DC motor, is the most favorable motor for our aircraft. It is
capable of 13 pounds of thrust which is suitable for our aircraft since it is about 23
pounds. The size of its propellers is 26 x 10 inches which roughly measures up to two
floor tiles which is adequate for our plane. In comparison to the other motors given, it
holds the maximum power of 1800 watts at 8,000 RPM which provides more than
enough power. Additionally, the input voltage ranges from 18.5 – 22.1 V, which is
reasonable because of the maximum power it can exert.
E-20
Description
Brushless, DC Electric
Unit weight, including gearbox, propeller, and speed
1.1 lbs.
control
Propeller
18 x 8 (inches)
Maximum power
1800 Watts @ 8,000 RPM
Static Thrust at Sea Level, Standard Conditions
13 pounds thrust
Engine Efficiency
96%
In-flight propeller efficiency
80%
Input voltage
18.5-22.1V
Batteries
Not included
Motor Dimensions
2.3 diameter x 2.3 length
(inches) cylinder, coaxial with
propeller
Cost
$295.00
We plan to use lithium ion (TS-LYP) batteries to power our aircraft since we are
going electric. The TS-LYP is a lithium-ion battery that has an improved nickel-based
positive electrode which allows high capacity and durability. It stores 720 watts per
kilogram which is enough to power our aircraft’s mission within a reasonable amount of
time. We avoid the inconvenience of having to wait and refuel, for all we do is swap out
31
batteries. Due to the information we extracted about the E-20, we voted that it was the
best suited for our aircraft.
2.3.2 Sensor Payload Selection
For our sensor payload, we chose the X3000. It has a reasonable price compared to
both the X4000 and X5000, as well as being light. The X3000 also includes a decent roll
and pitch limit of 80 degrees in all directions which surpasses the more expensive
X5000. Additionally, the X3000 has a continuous zoom of 1x wide angle to 10x
telescopic which is suitable enough to determine a child's face. However, among all the
cameras, the X3000 has the greatest power draw. Therefore, we will install two microalternators to supplement the power needs of the X3000.
*** - Chosen sensor payload
Details:
Sensor Payload Model: X3000***
Price $38,000
Stabilization: Excellent
Imager: Daylight Electro-Optical Camera
Roll Limits about x-axis: 80° pan left
80° pan right
Pitch limits about y-axis: 80° tilt up
80° tilt down
Roll/Pitch Slew Rate: 200° per second
Video Format: NTSC
Video Frame Rate: 30 frames per 1.001 second
Video Scan: Interlaced
Continuous Zoom: 1x Wide Angle to 10x Telescopic
Camera Profile: Horizontal:
Vertical:
Resolution: 640 pixels
480 pixels
Wide Angle Field of View: 55.00°
5.500°
Telescopic Field of View: 41.25°
4.125°
Weight: 2.10 pounds
Center of Gravity: (measured from front, right corner at red X)
X: 2.00 inches
Y: 2.00 inches
32
Z: 0.75 inches
Dimensions when Internal Volume:
External Volume:
mounted:
X Length: 4.00 inches
4.00 inches
Y Width: 4.00 inches
4.00 inches
Z Height: 1.00 inch
2.00 inches
Voltage In: 9-24 volts
Power Draw: 10 watts (nominal)
14 watts (maximum)
Sensor Payload Model: X4000
Price $42,000
Stabilization: Excellent
Imager: Daylight Electro-Optical Camera
Roll Limits about x-axis: 85° pan left
85° pan right
Pitch limits about y-axis: 85° tilt up
85° tilt down
Roll/Pitch Slew Rate: 200° per second
Video Format: NTSC
Video Frame Rate: 30 frames per 1.001 second
Video Scan: Interlaced
Continuous Zoom: 1x Wide Angle to 16x Telescopic
Camera Profile: Horizontal:
Vertical:
Resolution: 640 pixels
480 pixels
Wide Angle Field of View: 64.00°
48.0°
Telescopic Field of View: 4.0°
3.0°
Weight: 4.25 pounds
Center of Gravity: (measured from front, right corner at red X)
X: 2.5 inches
Y: 2.5 inches
Z: 0.0 inches
Dimensions when Internal Volume:
mounted:
33
External Volume:
X Length: 5.00 inches
5.00 inches
Y Width: 5.00 inches
5.00 inches
Z Height: 2.25 inch
2.00 inches
Voltage In: 5-18 volts
Power Draw: 2.5 watts (nominal)
5 watts (maximum)
Sensor Payload Model: X5000
Price $75,000
Stabilization: Excellent
Imager: Daylight Electro-Optical Camera
Roll Limits about x-axis: 70° pan left
70° pan right
Pitch limits about y-axis: 70° tilt up
70° tilt down
Roll/Pitch Slew Rate: 250° per second
Video Format: NTSC
Video Frame Rate: 30 frames per 1.001 second
Video Scan: Interlaced
Continuous Zoom: 1x Wide Angle to 30x Telescopic
Camera Profile: Horizontal:
Vertical:
Resolution: 640 pixels
480 pixels
Wide Angle Field of View: 60.00°
45.0°
Telescopic Field of View: 2.0°
1.5°
Weight: 7.50 pounds
Center of Gravity: (measured from front, right corner at red X)
X: 6.00 inches
Y: 6.00 inches
Z: 0.00 inches
Dimensions when Internal Volume:
External Volume:
mounted:
X Length: 12.00 inches
12.00 inches
Y Width: 12.00 inches
12.00 inches
Z Height: 4.75 inch
5.00 inches
34
Voltage In: 12-30 volts
Power Draw: 15 watts (nominal)
25 watts (maximum)
2.3.3 Ground Station Equipment Selection: $57,785.45
2.3.4 Additional UAV/UAS Equipment: $4,692
Item
Cost / Item
Quantity
Overall cost
Video Data Link UAV Transmitter
$200
1
$200
Command Data Link UAV Transmitter
$300
1
$300
Flight Control System
$2,000
1
$2,000
Lithium-ion (TS-LYP) Batteries
$105.75
16
$1,692
Back-up Diesel Generator
$500
1
$500
Total Cost:
Item
$4,692
Cost
Ground Station Equipment Total Cost
$57,785.45
Additional UAV/UAS Equipment Total Cost
$4,692
35
Total Cost of all Equipment:
$62,477.45
2.4 Aircraft Geometric Details
2.4.1 Wing Configuration Detail
We have tried several airfoil designs, but the NACA 4415 came out to be the best. The
NACA 4415 airfoil showed pretty good results from javafoil testing as compared to the other
airfoils we considered (NACA 0010 and the SD 7032). It was also an airfoil design that
made sense. Short near flat bottom to let more air pass through and increase air pressure
below to create lift, aerodynamically curved top to reduce lift-induced-drag, but also slow air
particle moving across the top to reduce upper air pressure and create lift.
o
Wing area: 414 square inches
o
Airfoil selection: NACA 4415
o
Aspect ratio: 11.3 inches
o
Taper ratio: .57 inches
o
Wing root chord: 7.711 inches
o
Wing tip: 4.395 inches
o
Dihedral angle (high wing): Sine 5 degrees
o
Wing Sweep: 4.1575 degrees
o
Max chord thickness inboard wing: 1.15 inches
o
Max chord thickness outboard wing: 0.658 inches
o
Wing thickness: 0.825 inches
o
Inboard wing chord: 7.711 inches
o
Outboard wing chord: 4.395 inches
o
Area of winglet: 13.15 square inches each
o
Thickness of winglet: 0.463 inches
36
o
Mean aerodynamic chord: 6.204 inches
o
Winglet dihedral: 85 degrees
o
Angle of incidence to fuselage: 1.58 degrees
Mean aerodynamic chord
2.4.2 Tail Configuration
The design we needed was a horizontal tail with a planform that would balance out with the
front wing in the boom with the batteries and vertical tail while balancing the CG. Within the
CG limit with was somewhere between 14 inches -15 inches back. The v-tail is for the
aircraft and being able to catch enough lift to turn the aircraft. So we needed a planform for it
that made would let it take up enough lift to overcome the dihedral in the front, but not by too
much. If you look at our aircraft from the side you see that our wing from the side with the
winglets nearly matches our vertical tail. Also for balancing purposes, we wanted the tail to
37
be as far back as possible so using the tail volume coefficient we were able to calculate the
correct area for our tail so that it would be situated completely at the back of the aircraft.
o
Tail type: Conventional
o
Horizontal stabilizer area: 70.967 square inches
o
Horizontal tail thickness/chord: 14.9%
o
Horizontal taper ratio: .57
o
Horizontal stabilizer aspect ratio: 2.825 inches
o
Horizontal tail sweep: 9.7078 degrees
o
Vertical stabilizer area: 28.02 square inches
o
Vertical taper ratio: .333
o
Vertical stabilizer aspect ratio: 2.1
o
Vertical tail thickness/chord: 14.9%
o
Vertical tail sweep: 38.61 degrees
2.4.3 Fuselage
The general components of our aircraft composes of the video data transmitter,
command data transceiver, flight control (autopilot), the E-20 propulsion system, the
X3000 sensor payload, and four of our batteries. We wanted these general components
to be as close as possible to reduce the size of the aircraft which is why we have most of
the components lumped up in the front "head" of the aircraft. The boom was just large
enough to hold the batteries like the back of a flashlight the tail and the batteries stabilize
the aircraft and balance out the front.
38
The picture above shows the location of the components which are mostly on the front of
the aircraft.
o
Fuselage wetted area: 264.18 square inches
o
Fuselage length: 33 inches
o
Fuselage depth: 3.30 inches
This picture shows the change in the diameter of the fuselage with each inch (FS).
39
Bottom view of our aircraft and the locations of the components
40
2.5 System and Operation Conditions
The entire unmanned aircraft system, from the sensor payload to the ground station,
was chosen under careful consideration. The team made choices based on the cost, weight,
and size of each individual component. On the other hand, heavier and pricier components
were still considered if they compensated for that simple disadvantage.
In choosing the sensor payload, we were able to narrow it down to the X1000, X3000,
and X4000. After a systematic review, the X3000 was chosen to complement our aircraft.
Our final decision was based on the fact that the X1000 wasn’t capable of zooming in and
the X4000 was too bulky and heavy for our aircraft. Fortunately, the X3000 included wide
rolling angles, along with 10x telescopic photo capabilities. Its size allowed it to fit within the
geometry of our aircraft and its price was reasonable. The major disadvantage of the X3000
was its large power draw, however; we compensated for this by modifying the aircraft’s
system.
We would now have four aircrafts in our system. This setup contains four of each basic
function, including the personnel needed to operate each station. We decided to purchase
the two fleet trailers because it had a better bargain to accommodate four small UAV’s that
are less than five feet each and its associated equipment.
We had two major search patterns that we discussed constantly: the spiral search with
one UAV versus the sector track with two UAV’s versus four UAV’s. Initially, we decided to
use the sector track method because it would complete the mission in a shorter amount of
time than the spiral search. However, the spiral search would cost less because there would
only be one aircraft involved. With the additions of tall trees, short trees, and no trees
section, we had to conform to the challenge. Additionally, during a discussion, we assumed
that mission would be completed faster when one aircraft would start in the “no trees”
section and the other would begin in the “short trees” section. On the other hand, although
the spiral search would cost less, it would take more time to complete the mission. On
November 27 during the Webinar, we asked the mentors about the effects of flying in a
spiral; they responded that the rolling angle would not be significant enough to alter the
lateral coverage area of the camera. This information added to the pros of the spiral search.
We analyzed the merits of each search pattern and it came out that the sector track search
was better than the spiral search. We would have enough lateral coverage between turns for
the X3000. We wanted to find the injured child alive as soon as possible. The time one
aircraft would have to complete all three sections of the search area would take an
unreasonably long amount of time. As a result, we made our final decision based on the
41
time and coverage. We then had to make the decision whether to use two aircraft or four.
We calculated the time for four aircraft versus two aircraft and it came out that having four
aircraft would be a better choice. Although the cost would increase because of the additional
UAV’s, we calculated the objective function for both systems and the objective function for
four aircraft was lower than the system with two aircraft.
2.6 Component and Complete Flight Vehicle Weight and Balance
According to a source (flysafe.raa.asn.au/groundschool/umodule9.html), an aircraft’s CG
range is between 15 to 35 percent of its mean aerodynamic chord, therefore our aircraft’s CG
range is between 10.43 and 11.35 inches from the nose. With the Configurator, we were able to
calculate that our aircraft’s center of gravity is 10.51 inches from the nose and therefore well
within the CG range. All components including added airbrakes and actuators are included in
the configurator as well.
42
43
Bottom view of CG
Top view of CG
44
2.7 Maneuver Analysis
Maneuver Analysis
During normal cruise, the maximum amount of pan our camera has to perform for this mission is
27.2. Our Camera’s maximum pan or roll in any direction is 80 degrees. Therefore, our aircraft
is capable of taking the maximum bank of 30 degrees without losing coverage and thereby
minimizing our turn radius shown here.
These turn radii were chosen due to them being equal to the fore-and-aft coverage of our
camera during operation. The small trees and no trees (shown in the camera#2 footprint)
section have 474 feet of fore-and-aft coverage. The tall trees section has 322 feet fore-and-aft
coverage.
45
Tall Trees Section
Short Trees Section
46
2.8 CAD Models
View of components inside the aircraft
Bottom view of the aircraft
47
Side view of the aircraft
Top view of the aircraft
2.9 Three View of Final Design
Full Aircraft Dimensions:
Fuselage:
o
Length: 33 inches
o
Greatest Height: 3.3 inches
o
Greatest Width: 5 inches
o
Least Height: 1 inch
o
Least Width: 1 inch
o
Wetted Area: 264.18 inches
o
Weight: 6.13 lbs
Wing:
o
Planform Area: 414 sq. in.
o
Aspect Ratio: 11.3 ~
o
Taper Ratio: .57~
o
Sweep: 4.1575 deg (wing back edge is flattened to compensate for flapperons)
o
Dihedral: 5 deg (to keep the aircraft aerodynamic laterally and keep the side-slip angle at
0)
o
Wind Incidence: 1.56 deg (Produces aircraft’s weight in lift at cruise speed)
o
Wing Root Leading Edge Location: [8 0 1.2296] in. (coordinate reference is the nose of
the aircraft, wing is mounted directly atop and aligned with its fuselage station)
48
o
Wing Span: 68.397 inches
o
Semi-Span: 34.199 inches
o
Root Chord: 7.711 inches
o
Tip Chord: 4.395 inches
o
Mean Aerodynamic Chord: 6.204 inches
o
Wing Aerodynamic Center: [11.05 15.538 2.388] in.
Horizontal Tail Wing:
o
Aerodynamic Center: 30.557 in. (distance from nose of tail’s quarter chord)
o
Tail Arm: 15.517 in.
o
Planform Area: 70.97 sq. in.
o
Aspect Ratio: 2.83 ~
o
Taper: .95
o
Sweep: 9.71 deg (flatten the back edge of Horizontal tail)
o
Anhedral: 5 deg
o
Span: 14.894 in.
o
Root Chord: 5.7.
Vertical Tail Wing:
o
Planform area: 28.02 sq. in.
o
Sweep: 38.61 ~
o
Thickness/chord: 0.15 ~
o
Aspect Ratio: 2.10 ~
o
Taper Ratio: 0.33 ~
Winglets:
o
Area of winglet: 13.15 square inches each
o
Thickness of winglet: 0.463 inches
o
Mean aerodynamic chord: 6.204 inches
o
Winglet dihedral: 85 degrees
o
Angle of incidence to fuselage: 6 degrees
49
3. Document the Mission Plan
3.1 Search Pattern
The search pattern had to be changed in order to accommodate the needs of the
national challenge. The search area for the national challenge has three different sectors with
various tree lengths, creating an obstacle for our aircrafts. The size and description of the
sectors include one area sized at 160 degrees central angle of the circle containing tall trees;
110 degrees central angle of the circle with no trees; and 90 degrees central angle of the circle
composed of short trees.
After a discussion over the best suitable search pattern, the team decided to use the
track method to scout the designated search area. Additionally, the team decided on four
sUAVs to search the area as opposed to two aircrafts. Having four aircrafts would best minimize
the objective function, which is part of the national challenge, as well as acquiring a shorter time
length. The four aircrafts are designated into different sectors: one for the area with no trees,
one for the area with short trees, and two sUAVs will accommodate the area with the tall trees.
The sector with tall trees is much more complex than the other two search areas, thus two
aircrafts were chosen to complete the search area in order to narrow our lateral coverage which
includes 19 tracks. Likewise, it would be more time efficient for two aircrafts to tackle the search
area composed of twenty tracks, one aircraft searching the area with the short trees containing
10 tracks, and one aircraft scouting the area comprised of no trees with six tracks. Each aircraft
is given enough time to search the sector carefully, making sure no area is omitted.
Each of the four aircrafts will start in the center of the search area. Moreover, one of the
two aircrafts designated for the tall trees sector will take the first track while the second aircraft
scouts the second track; both airplanes are given individual tracks in the tall trees sector to
prevent any accidents. The two planes will continue to fly out together in a zig-zag motion until
they reach the circumference of their sector, finishing their designated area. The other two
planes will use the same method to search their respective search areas. Concurrently, during
the mission no aircraft will alter their altitude to prevent losing their lateral coverage.
In order to avoid any dangerous crashes, each sUAS will fly to the ground station
instead of the center upon completion of its designated sector. Hence, the mission will be
completed once all four aircrafts have reached the ground station.
50
3.2 Camera Footprint
No Trees Sector Search
Mission Planning Worksheet does not account for the fore and aft coverage of the camera,
which would complete the coverage area of the sector and remove the white spots.
51
Short Trees Sector Search
Tall Trees Sector Search 1
52
Tall Trees Sector Search 2
3.3 System Detection and Identification
The aircraft’s operating speed will be a little over 72.46 miles per hour. While at the
assigned cruise velocity and flight altitude, the camera will start viewing at 4 pixels wide
range which is considered the software detection resolution. Additionally, as the flight
progresses and the operator is able to detect various blue objects from the sensor payload,
our aircraft will decelerate from cruise velocity, in order to facilitate enough time for full
detection. The next step is to increase the camera’s view from 4 pixels to 8 pixels, which is
considered the human detection resolution. Finally, the camera will process the 8 pixels
wide view to a 20 pixels wide view for the confirmation resolution. If the confirmation
resolution is confirmed as the child, the aircraft will send back the coordinates to base
station in real time. On the other hand, if the confirmation is negative, the flaperons will
retract and the aircraft will return to its assigned cruise speed. This process will be repeated
until the mission is completed.
The restriction of the “tall trees” zone is a limited 15 degree horizontal field of view, the
“short trees” zone is a limited 30 degree horizontal field of view, and the “no trees” zone has
no restrictions and provides the opportunity of the widest search coverage.
The zone with short trees has 31.5 degrees field of view for the camera and the camera
will pan 13.5 degrees left and right continuously until the end of the search route for that
sector. The tall trees zone has 31.5 degrees field of view for the camera to have the camera
53
detection box to cover the full horizontal area of the limited 15 degrees field of view and the
camera will face straight down to detect the object and will be able to search the whole area.
The zone with only grass will be detected by 27.4 degrees field of view which will increase
our detection radius and we will pan left and right 27.45 degrees to cover the whole
horizontal area to reduce the amount of turns needed to fully search the entire sector.
3.4 Example Mission
The Aeronautical Dolphins designed a new innovative UAV that will be able to respond
to the given search and rescue operation.
A person reported a potentially injured and
immobilized child, who is wearing a blue jacket, and was reported missing at Philmont Ranch, in
New Mexico. The search team concluded that he might be somewhere in a designated 2-mile
radius search area which has three different sectors with various tree lengths, creating a
challenge for our aircrafts. The largest sector is composed of tall trees, the second largest
sector is composed of no trees, and the smallest sector has only short trees. Furthermore, our
primary objective is to locate the child as soon as possible, while minimizing the cost. Thus, the
team concluded that we will use an arc method in order to complete the search area with these
different sectors as well as increasing our aircraft operation from 1 to 4 sUAS. Since the largest
sector is composed of the tall trees, we will have two aircraft flying adjacent arcs in order to
expedite the searching process.
After we received a confirmation of a mission, we will rush out to our vehicles with our
new and advanced, unmanned aircraft system called the Dragonfly I, II, III, and IV as well as our
ground station equipments and crew. It will take us approximately 3.5 hours to travel from
Colorado Springs (our home base) to New Mexico. After we arrived to the Philmont Ranch, we
will quickly assemble our computers, data link ground receiver, and data link ground transceiver.
It will take us approximately 0.5 hour to set up our ground station. After we set up our ground
station, then we will launch all four Dragonflies with the aid of a catapult located in the center of
the search area.
As each Dragonfly takes off, it will begin to fly at 45.71 mph and will continue to climb
until it reaches a cruise altitude of 1000 feet and a cruise speed of 73.42 mph. It will take each
of the Dragonflies approximately 27 seconds to reach cruise altitude.
The Dragonfly which is responsible for searching the no trees sector has a total of six
arcs to search. Once the Dragonfly completes the takeoff and enters the outer most arc of the
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no trees sector, we have already used up 14.36 watts for our batteries. The only times we will
slow down our speed to 48.42 is when we are approaching the end of the arc and entering into
the turns. Furthermore, the first five turns for the no trees sector have the same ¼ turn and
same mid-turn dimensions. While entering the first ¼ turn, we will maintain the speed of 48.42
and once we reached our straightway we build up velocity to 73.42. Again, we will once again
slow down the Dragonfly per second for our last ¼ turn thus building up speed once we enter
the next arc. Each arc is located at a different distance from the center of the circle of the
search area. As we get closer to the center of the search area, the lengths of the arc get shorter
and the dimension of our last turn deviates from the previous turns. During the process, in which
Dragonfly’s sensor payload has detected a blue object, the aircraft will slow down from a cruise
speed of 73.42 mph to 48.42 mph at a rate of 5 miles per second. Once it reaches 48.42 mph,
and the object detected is not a child, then the aircraft velocity will increase back to 73.42 mph,
at a rate of 5 miles per second. Once cruise speed is obtained, then the aircraft will continue
with the normal searching process. This process will be repeated within all sectors. We have
managed to search the whole no trees sector in just 14.50 minutes, with a total usage of
326.712 watts that includes power for the components and the motor. The no tree section will
have two detection and identification sequences.
For the short trees sector, the Dragonfly has a total of 10 arcs and nine turns to search
on. The same process for detection and identification, entering and finishing the arcs, and
entering and finishing each ¼ turns and straightway will be applied for this sector. About three of
our straightway turns are much longer and much shorter than the rest, but again the same
process will be applied in entering the straightway and entering the last ¼ turn. It took us
approximately 14.26 minutes to complete this sector with just one detection from our sensor
payload. In those 14.26 minutes we used a total of 315.433 Watts from both our motor and our
components.
Since the largest sector is composed of the tallest trees, we will have two aircrafts
searching together in that sector. For example, after takeoff, one of the two aircrafts designated
for the tall trees sector will take the first track or the outermost arc while the second aircraft
searches the second track. To prevent any accidents, such as collusions, both airplanes are
given individual adjacent arcs in the tall trees sector. The two planes will continue to fly out
together until they complete their designated area. This sector has a total of 19 arcs and a total
of two detection and identifications from our sensor payload. This arc took up an approximate of
33.124 minutes and a total of 703.238 Watts.
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Once the whole sectors for the whole search area have been completed all that
information will be sent to the ground station. Finally, a search party will assemble and use
established coordinates to rescue the injured child. Our tear down time is approximately 0.5
hour and driving back to our base at Colorado Springs will take up approximately 3.5 hours thus
ending the whole search and rescue operation.
3.5 Mission Time and Resource Requirements
Upward Acceleration Equation:
0.5 ∙ 𝐴𝑖𝑟 𝐷𝑒𝑛𝑠𝑖𝑡𝑦 ∙ 𝑊𝑖𝑛𝑔 𝑃𝑙𝑎𝑛𝑓𝑜𝑟𝑚 𝐴𝑟𝑒𝑎 ∙ [(𝐼𝑛𝑖𝑡𝑖𝑎𝑙 𝑆𝑝𝑒𝑒𝑑 + 𝐴𝑐𝑐𝑒𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛) ∙ (𝑀𝑃𝐻 − 𝑡𝑜 − 𝐹𝑃𝑆 𝑅𝑎𝑡𝑖𝑜)]2 ∙
(𝐸𝑎𝑟𝑡ℎ − 𝑝𝑜𝑢𝑛𝑑 − 𝑡𝑜 − 𝑁𝑒𝑤𝑡𝑜𝑛 𝑅𝑎𝑡𝑖𝑜) ∙ (𝑀𝑒𝑡𝑒𝑟 − 𝐹𝑒𝑒𝑡 𝑅𝑎𝑡𝑖𝑜)
(Aircraft Weight ∙ Pound − to − Kg Ratio)
The Definite Integral of Upward Acceleration Equation for 0 to 1 is CLIMB RATE.
1
∫ 𝐴𝑐𝑐𝑒𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛 = 𝑉𝑒𝑙𝑜𝑐𝑖𝑡𝑦 = 𝐶𝑙𝑖𝑚𝑏 𝑅𝑎𝑡𝑒
0
1
∫ 𝑉𝑒𝑙𝑜𝑐𝑖𝑡𝑦 = 𝐴𝑙𝑡𝑖𝑡𝑢𝑑𝑒 𝐺𝑎𝑖𝑛𝑒𝑑
0
How to Calculate Acceleration:
(Maximum Thrust − Drag) ∙ (Earth − Pound − to − Newton Ratio) = Force
m
Force
Acceleration ( 2 ) =
s
Aircraft Weight ∙ ( Lb − to − Kg Ratio)
56
m
m
mph
Acceleration ( 2 ) ∙ ( − mph ratio) = Acceleration (
)
s
s
s
(
(13.00 − 4.028) ∙ 4.448
mph
) ∙ 2.237 = 8.747
22.5 ∙ 0.454
s
Mission profile:
Tall Trees Sector
Dragonfly I
1. Begin search pattern and detection:
After assembly of the ground station, located in the center of the search area,
each aircraft will be catapulted into their respective sectors. After the aircraft becomes
airborne, it will continue increasing altitude until it reaches a cruise altitude of 1000 feet,
attaining a cruise speed of 73.42 miles per hour. One aircraft out of two designated in
the tall trees sector will be catapulted to its designated area, which is composed of 19
arcs. Upon obtaining both the cruise speed and the cruise altitude, both aircrafts will be
searching the tall trees area following a selected area which crosses over the sector.
Once our camera captures what could be the injured child wearing a blue jacket, the
aircraft’s velocity will slow down by decreasing power, while increasing the angle of
attack and extending the flaperons upward to act as makeshift spoilers. Thus, we will be
able to maintain our altitude without compromising our lateral, forward, or aft coverage.
Furthermore, the aircraft’s sensor payload, the X3000, will zoom in and confirm if the
unidentified object is indeed the child that we are looking for. If the object is not the
missing child, the search will continue until the mission is completed.
2. Identifying the “false” matches – Emphasize detection and identification:
The same process will be repeated for detections and identifications. During
detection, the aircraft will fly at cruise altitude. As a result, our camera can only detect
what the child is wearing. However, if a blue object is spotted the aircraft will decrease
speed and zoom into the objected until it is identified.
Additionally, the process of
detection and identification of the child involves total team effort in order for a successful
mission.
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Dragonfly II
1. Begin search pattern and detection:
Similar to the Dragonfly I, the Dragonfly II is the second aircraft designated
towards the tall trees sector. Upon completion of ground station assembly, Dragonfly II
will be catapulted to the tall trees. After becoming airborne, the altitude will continue to
increase until it reaches the cruise altitude of 1000 feet and a cruise speed of 73.42
miles per hour. Once the desired speed and altitude are obtained, the aircraft will begin
searching the tall tree sector while parallel to the Dragonfly I which uses a selected arc
crossing over the sector. Once the X3000 captures what could be the injured child, the
Dragonfly II will slow down by using the same process the as the Dragonfly. Thus, the
Dragonfly II will be able to maintain its altitude without compromising its lateral, forward,
or aft coverage. Afterwards, the Dragonfly II will zoom in using the same process as the
Dragonfly I.
Short Trees Sector
Dragonfly III
1. Begin search pattern and detection:
The Dragonfly III will be also be catapulted to the short trees sector consisting of
10 arcs. Additionally, when the aircraft becomes airborne it will increase altitude until it
reaches the desired cruise speed and cruise altitude equivalent to the Dragonfly I and
the Dragonfly II. After the speed and altitude are acquired, the aircraft will begin its
search of the short trees sector using a selected arc, which also crosses over. Once the
Dragonfly III’s sensor payload captures what could be the injured child, it will use the
same process used by the Dragonfly I and the Dragonfly II. Concurrently, this will allow it
to maintain altitude without compromising the lateral, forward, or aft coverage.
Additionally, the Dragonfly II will zoom in using the same method as the Dragonfly I and
II.
No Trees Sector
Dragon IV
1. Begin search pattern and detection:
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The Dragonfly IV will be launched into the no trees sector composed of 6 arcs
after the Dragonfly I, II, and III are catapulted into their designated search areas. After
becoming airborne, it will increase the altitude until it reaches the desired cruise altitude
of 1000 feet and a cruise speed of 73.42 miles per hour. Once attaining the cruise
altitude and cruise speed, the aircraft will begin searching its designated sector by using
a selected arc which crosses over the sector. Once the X3000 detects an object similar
to the injured child, the aircraft will slow down its velocity with the same procedure
implemented by the three previous aircraft. It will likewise maintain its altitude without
compromising its lateral, forward, or aft coverage. Thus, it will zoom in using the same
procedure employed by the three previous aircraft.
* Rescuing the missing child:
As the “worst” case scenario, we will detect the missing child towards the end of the
search mission. Once we have positively identified the young boy’s position, we will send
the way points back to base and begin the ground search. The ground search team will be
composed of local volunteers.
Manpower requirements:
o
1 X Payload Operator
o
4 X Operational Pilot
o
1 X Range Safety/Launch and Recovery/Maintenance
o
4 X Safety Pilots
4. Document the Business Case
4.1 Identify Targeted Commercial Applications
It is common knowledge that one of the basic benefits of a small Unmanned Aircraft
System is to increase safety measures when handling dangerous missions, which can be
inferred from a military standpoint. Flying an aircraft through enemy territory is heroic, but
suicidal. With the help of sUAVs, the military is capable of spying on their enemies and
finding ways to counterattack them.
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As time advances, sUAVs have evolved to be used for other purposes which include
helping out civilian government agencies and other individuals. The challenge is a good
example of its involvement with rescue and search operations. Other operations in demand
of sUAVs are commercial aerial surveillances which include agricultural monitoring,
firefighting, and security or law enforcements. Take for example the Puma Unmanned
Aircraft System which weighs about 13 pounds and can stay in flight for around two hours.
Just like our aircraft, it is powered by batteries and accommodates a high definition camera
that is capable of streaming videos by computer. These aircrafts can be used to monitor
animal population in the ocean since it is capable of landing on both water and land.
However, if regulatory restrictions were eased, then our sUAVs could be considered an
oversized remote control toy for the amusement of anyone interested. For the most part,
small Unmanned Aircraft Vehicle systems are used for missions that are too “dull, dirty, and
dangerous” in comparison to other aircraft systems.
There are many rules provided by the FAA that regards to sUAVs. With disregarding
some of these rules that the FAA provides, the Dragonfly is able to save more lives that are
in danger and could be beneficial to the ground operations crew. An example of this is that
operations should be conducted within visual line of sight to the pilot or operator. Imagine
the pilot constantly looking up at the aircraft and constantly rotating his or her head. It’s a lot
of work. So what we could do to prevent that from happening is to keep the visual line of
sight by installing a forward facing camera while the aircraft is flying. The best part is that the
pilot and sensor payload operator could operate the aircraft in home base. They don’t
actually have to be in the field operation. The only people that could be there is the
maintenance personnel such as the safety pilot, the people in charge of the catapult, and
the people in charge of setting up the nets.
Another rule is that operations should be conducted on a clear day. But what if in the
middle of the operation, it starts to rain followed by heavy winds? Should we cancel the
operation right there? What will happen to the missing person? So if this rule was not in full
effect, then we could still go on with the operation whether it’s a clear day or not. For our
aircraft to continue the operation with no problems with the weather, we could modify it. For
example, we could apply this super hydrophobic spray that is developed by Ross
Nanotechnology. And what it does is that it repels water or any other liquid that the surfaces
touch. So it acts like a wiper for the cameras.
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This applies to the rule night operations shall not be conducted. Why is that? What if
someone reported a missing and injured person late afternoon? Shall we just postpone the
operation at night? What will happen to that person? Will his injuries worsen? Of course yes!
If we cancel out the night operation not being conducted by the FAA, then we could still save
the person. Of course that also means that we got to have sharp eyes. That also includes
modifying our aircraft. This modification includes our camera acting like night vision, install
external lights so that we could see the aircraft flying, and install infrared lights to detect heat
signatures.
Basically with eliminating operations to be conducted within VFR weather requirements
and night operations, we could still save lives that are in danger.
*Other rules regarding UAS is basically having certification, authorization, or permission to
operate the UAS at a certain point and a certain distance. Examples are UAS cannot be
conducted over: military bases, national parks, wildlife preserves, etc. These parameters
cannot be changed.
4.2 Amortized System Costs
4.2.1 Initial Costs : $231,026.17
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62
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Initial Cost: $231,026.17
System Per-Hour Cost: $1,375.00
4.2.2 Direct Operation Cost per Mission
Four small coordinated aircraft systems flying at high altitude, each having one sensor
payload, one video transmitter, and real-time ID software at the ground station. Aircraft
flight endurance for the electric battery-powered UAV is equal to 1 hour total flight time
per aircraft. Ground-Team consisting of:
o
1 X Payload Operator (150/hr. per analyst)
o
3 X Ground Search Personnel
o
4 X Safety Pilot (100/hr. per pilot, 400/hr. total)
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o
4 X Operational Pilot (150/hr. per pilot, 600/hr. total)
o
1 X Range Safety/L&R/Maintenance Officer (175/hr. per officer, 175/hr. total)
o
Launch & Recovery Assistants (50.00/hr. per assistant, 50/hr. total)
Travel time to location: 3.5 hours driving from HQ in Colorado Springs, CO
Set-up time: 0.5 hour
Flight time to rescue: 16 minutes 27 seconds
Tear-down time: 0.5 hour
TOTAL OPERATION TIME: 4 hours 46 minutes and 27 seconds
Per-System Operational Cost per Hour: $1375
TOTAL Operational Cost per Mission: $849,184.27
4.2.3 Amortization $16,983.69
The team used MathCAD to find the amortization cost of our sUAS. We added our initial
system cost and the total operational cost per mission for fifty missions and then divided
this total cost by fifty missions. Therefore, our amortization cost is about $16,983.69
Fully burdened cost of 50 missions divided by 50
65
849,184.27 / 50 = 16,983.6854
4.3 Market Assessment
Small unmanned aircraft vehicles are being used for reasons that particularly involve search
and rescue missions. There is also a noted rise for utilization of sUAS by many organizations
which includes the military. AeroVironment manufacturers sUAS that “are used extensively by
U.S. military forces, and increasingly by allied forces, to help establish Intelligence, Surveillance
and Reconnaissance (ISR) superiority on the front lines of today’s hot zones. In fact,
AeroVironment’s Dragon Eye, Raven, Wasp and Puma AE have won each of the four U.S.
Department of Defense full and open competitions for programs of record involving small UAS.”
In an email from Carly Garrison, who works under Business Development for AeroVironment,
inquired that most of the prices of a whole system that includes three UAS, a ground control
system, a video terminal, and spare equipment costs about $300,000 with the individual costs of
sUAS to be about $35,000. AeroVironment’s “Qube” which is a sUAS capable of completing a
search and rescue mission has a price of $49,795, extra batteries and other extra items will be
charged extra. Garrison emphasized that it was important for her company to keep it under
$50,000, which is a normal price for a police cruiser.
The U.S. Coastguard also conducts search and rescue missions. They use a variety of
manned aircrafts such as the Sikorsky HH, Lockheed HC-130J Super Hercules, and the
Dassault HU-25 A/C/D/ Guardian. With all these vehicles and the equipment needed, the
system would not be affordable. Add in the costs of the pilots, too. Helicopters and other aircraft
would cost more than our whole sUAS. In our system, although we only use one aircraft to
search, we determine the exact location first in order to be efficient with our resources. Our
unmanned vehicle is purely electric and recharging batteries would cost much less than
procuring petroleum.
Conversely, both AeroVironment and our team designed an aircraft that was capable of
a search and rescue mission. Just like “The Dragonfly,” AeroVironment’s sUAS are electricallypowered and manually launched. Through the use of a motor, both aircrafts remain noiseless in
flight and do not exhaust any byproducts, remaining very environmentally friendly. The
differences between our aircraft and sUAS manufactured AeroVironment was the competitive
price. The Dragonfly alone would cost a little less than a few thousands compared to the Qube.
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Our entire system alone would already include two sUAVs, ground equipment, and personnel
costs that would sum up to less than $120,000 which is less than the cost of AeroVironment’s
system. AeroVironment has priced their package roughly at $150,000 which includes three
sUAVs, ground station equipment, and spare equipment.
Meanwhile, the U.S. Coastguard also conducts search and rescue missions. Battling
against cost, having manned aircraft and a licensed pilot would be extremely expensive for an
organization. Our system cost gives companies an opportunity to own a sUAS at an affordable
and practical price. It would also decrease the number of casualties in a search and rescue
mission because it wouldn’t risk any more lives than the potential victims. In this case, it will help
rescue more people because the size of an unmanned aircraft is smaller than a manned aircraft.
A sUAS could easily maneuver in the search area as compared to a manned aircraft increasing
time efficiency.
4.4 Cost / Beneficial Analysis and Justification
Small unmanned aircrafts provide an inexpensive and safer way for search and
rescue missions. Notwithstanding, the cost for personnel during the search and rescue
mission will be costly. Our team has built an aircraft that will also help in reducing the time
for paid personnel. The design along with the business plan will provide both a feasible and
efficient answer to the targeted audience.
Material Selection
The material we chose for our aircraft is ceconite 101 and balsa wood. Ceconite 101
attains strength stronger than cotton with a higher durability. It is sold on the website
aircraftspruce.com with measurements of 72”, with every yard costing about $13.50. Besides its
strength, ceconite 101 has a possible lifetime durability which means that throughout the entire
lifespan of the aircraft, there is no need to change the fabric if it is maintained properly. This
saves you a lot of money in comparison to fabric that doesn’t achieve the same strength and will
command for changes throughout the lifetime of the aircraft. Likewise, we decided to use balsa
wood for the aircraft’s structure. Not only is wood easier to manipulate in comparison to other
materials, it is also light weight. Balsa wood is the lightest wood with phenomenal strength.
Nonetheless, balsa wood is also environmentally friendly, and to decrease carbon footprint,
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people are able to grow their own balsa trees. It is noted that there are programs set out to
protect the production of balsa wood wherein every time you cut down a tree, a new one is
planted to replace it. With the fast growth of balsa wood, it wouldn’t take long to harvest the
trees. The balsawood can also be found on aircraft spruce with measurements of 2" thick
boards, 3 ft. long from 3"-6" wide, costing $17.85 each. Both of our material selections are
lightweight with respect to the mission. The cost is also reasonable, especially with the lifetime
durability of ceconite 101 and the balsa wood’s efficiency.
Propulsion System Selection
The Dragonfly assists in the advancement of electric motor innovations. Electric motors
are noiseless, which would already stand out as an advantage against engines. Motors are also
environmentally friendly, lighter, and have less moving parts. More importantly, they have a
better power to weight ratio than engines. Conversely, the disadvantages of gas engines are the
sources of power which includes oil, natural gas, coal, and fossil fuels. Additionally, fossil fuels
are formed by once living organisms and take an extremely long period of time to be created;
therefore, fossil fuels are very limited in resources. There are also major consequences in
burning of fossil fuels that affect our environment and have added to human health concerns.
Furthermore, since fossil fuels are very limited because of how they are created, the cost is very
expensive and the cost would increase because of the aircraft’s need to refuel. A motor,
however, has less moving parts than an engine which means less maintenance for the aircraft.
Compared to an aircraft with an engine, an owner with an aircraft that has a motor, such as the
Dragonfly, would have decreased maintenance cost. Choosing a motor against an engine would
cost less for the customer. In the catalog, an engine with 13 lbs of thrust costs $545 while an
engine with 5.1lbs of thrust cost $499. Our propulsion system, the E-20 has 13 lbs of thrust,
exactly the same as the GL-25, and it also has more thrust in comparison to the GL-12.
Fortunately, the E-20 only costs $295 which is a lot less than both engines.
Energy Source
Since the Dragonfly uses an electric motor, it would need batteries that will be capable of
recharging. We chose lithium-ion batteries because it has high density, no memory effects, and
there are a variety of shape and sizes. The advantages of having no memory effects is the
ability to keep their charge capacity overtime making them excellent for long-term use and in
turn more cost-effective than other batteries. Conversely, the lithium-ion batteries are also
notably the lightest batteries with the most energy density. In the future, lithium-ion batteries will
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possibly have the capacity to store ten times more power and last about 6,000 charges (nanobattery). Additionally, other technological advances such as the paper battery would eventually
overcome the petroleum power density advantage. Henceforth, because of the innovations
presented in batteries and not in oil, a motor is the most advantageous way to go for now and in
the future because of its endless potentials. The easy manipulation of batteries makes it
cheaper than oil because of its abundant resources. On the other hand, for now we will require
a lithium-ion battery because it fits our requirements. We chose the lithium-ion battery TS-LYP
because it has an energy density of 720 watts per kilogram and each watt is $0.47. As we
calculated our battery power in regards to the time, our battery is capable of fully completing or
spiral search once, but twice before our aircraft needs to change batteries. With no need to land
in one mission, the cost of personnel is reduced and the time needed to find the missing child is
decreased. But what is going to charge our batteries? We are planning to charge the batteries
with a magnetic generator. The magnetic generator includes three magnets. Two magnets will
oppose each other, creating a magnetic field; the third magnet will create balance, while the
motor then converts the power of the force field to energy. The magnetic generator requires
very little energy to begin working, but after that, it makes its own energy requiring no energy
from outside forces. With these types of innovations, the owner of the aircraft will never pay to
power their aircraft again. The cost will be decreased because of the wonderful advantages of
using the E-20 motor and the advancement of battery technology.
Structural Decisions
The radius of the fuselage of our aircraft would increase from the propellers until it
reaches the sensor payload and then decrease; forming a boom. There was not much
equipment placed in the rear ends of the aircraft and to reduce weight, we decided to streamline
it. This design calls for less cost on materials and a lighter weight.
The decision to slim down the fuselage and create a boom was made in order to make
the aircraft much lighter and more aerodynamic. We reduced the original wetted area from
about 440 square inches down to 264.18 square inches. Most of the weight of the aircraft will be
accumulated under the wing near the center of gravity with the weight of the batteries in the
boom to balance out the aircraft.
The Dragonfly’s design includes winglets. Furthermore, winglets provide an increase in
climb during aircraft takes off, decreases the takeoff speed, and allows more laminated air to
flow over the wings. The winglets make it more efficient for the aircraft to be in flight. Since the
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winglets make the wings more efficient, the range of the aircraft is increased. Therefore, the
need to recharge becomes less and manned hours are reduced.
Our aircraft’s antenna placements are very important to the aircraft’s design and
function. The larger antenna will be placed on the left wing while the smaller antenna will be
placed on the right wing. The placements of the antennas are essential because now they are
able to counteract the torque, or rotation, that is created by the clockwise spin of the propeller.
Of course, the antennas are used primarily for communication, but we have extended the
functions of the antennas by adding anti torque of the propeller and added structural support of
the winglets. We have now tripled the productive profile of these units, therefore improving the
efficiency of the aircraft.
Search Pattern
Throughout the entire challenge, we were conflicted between the spiral search and the
three-sector search. The spiral will consume too much time while the three-sector search would
require four aircrafts. Considering the objective function, we calculated both systems and it
came out that the three-sector search that required four aircraft came out lower. Although both
search patterns enabled us to search every area of the given search route, the three-sector
search pattern was a more effective choice by greatly reducing the time needed to find the child
The time required by the three-sector search was a great help as it reduced personnel costs.
Sensor Payload
The Dragonfly only has one sensor payload which is the X3000. Using one sensor
payload lightens the weight of the aircraft and reduces cost as well as being able to perform the
required job. Although our design only uses one sensor payload, the X3000 is a powerful sensor
payload that does not need assistance from additional sensor payloads. It has an 80 degrees
rolling and pitching limits and 10x telescopic zoom. The X3000 is superior to the X1000 and the
X2000 because of the zoom features and telescopic field of view. Compared to the X4000, the
X3000 is only five degrees apart in rolling and pitching limits; the X4000 having 85 degrees. On
the other hand, the X5000 only has 70 degrees rolling and pitching limits. Although the X4000
and the X5000 have greater telescopic views than the X3000, our strategy plans that we would
slow down our aircraft and zoom in on a detected object. Our strategy compensates for our
telescopic view. Also, the X4000 and X5000 are quite expensive and already have many things
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in common with the X3000. Most importantly, our flight plan has been modified to adapted to the
unique qualities of the X3000
Additional Components
Initially, our aircraft was going to include a HiRat aircraft in order to charge our batteries.
However, we didn’t go through with the decision because of the high cost of this component.
The HiRat was proved unnecessary and too expensive since it was just a designated back-up
for the batteries.
The Dragonfly only has one sensor payload and one propulsion system. Choosing one
system component reduces the cost of the aircraft and the weight. The Dragonfly only needs
one engine because of its in size and weight. Conversely, the X3000 is a powerful sensor
payload that doesn’t need any assistance from additional sensor payloads. Most importantly,
the flight plan allowed us the capability wherein we won’t lose coverage even through it uses
only one sensor payload, which reinforces its efficiency.
Concluded from all of the above mentioned, the audience will find that the Dragonfly is a
good choice, if they decide for a market that includes both an efficient and affordable aircraft
system. Additionally, the price is negotiable which includes a sales promotion; the more you
buy, the cheaper the system.
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