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Team Members:
Brandon Fichera
Dave Rabeno
Greg Pease
Sean Gallagher
Sponsor:
Dr. Stephanie Wright
Delaware Aerospace Academy
Advisor:
Dr. Michael Keefe
Mission Statement:Mission Statement:To design a two person hovercraft for the To design a two person hovercraft for the Delaware Aerospace Academy that will Delaware Aerospace Academy that will demonstrate the scientific principles of a demonstrate the scientific principles of a hovercraft, foster teamwork between hovercraft, foster teamwork between students, and provide a fun, safe, and students, and provide a fun, safe, and educational environment for all students educational environment for all students involvedinvolved..
IntroductionIntroduction
SummarySummary
Introduction– Team, Sponsor, Advisor– Problem/Mission Statement– Background
Concept– Generation– Selection
Customers, Wants,
Constraints Benchmarking
– System– Functional
Metrics– Target Values
Concept Development– Test Results, Modifications– Recommendations– Prototype Evaluation
Budget– Construction hours– Engineering Hours– Prototype Cost
Problem BackgroundProblem Background
Delaware Aerospace Academy:Delaware Aerospace Academy:
• Sponsor of past UD senior design projects.
• Specializes in teaching kids about technology
involved in the space program.
Hovercrafts:Hovercrafts:
• New and exciting technology that has yet to be
widely distributed.• Interesting tool for teaching scientific principles
to children
CustomersCustomers DAA
• Dr. Stephanie Wright• Robert Bloom (Aerospace Engineer)
Students • High School Students• Junior High School - Eric Rabeno • Middle School - Ted & Elizabeth Pease
Teachers• High School - Martin Rabeno• Junior High School - Selina DiCicco
Industry • Ron Perkins - Educational Innovations
School System • Mark Ellison - Principle High/Jr High School
WantsWants Educational
– Demonstrate Hovercraft Principles to Children Recreational
– Make it fun, Cool Looking Operational
– - Maneuverable - Durable– - Reliable - Transportable– - Reproducible
Economical– - Low Cost
ConstraintsConstraints
Size of door in Spencer Lab (4.5’ by 6.3’)
Allowable Funds (~$2000)
Number of pilots (must be 2)
Operation (must be able to hover)
System BenchmarkingSystem Benchmarking
Triflyer - Hovercraft Design Pegasus - Hovercraft Design Universal Hovercraft - Hovercraft
Construction Kits Hover Club - Hovercraft Articles Science Project - Laboratory
Experiments
Smithsonian Air&Space Museum
use videos to excite peoples interest
Six Flags Amusement Parks
use acceleration and jerk for fun
Briggs and Stratton Engines
HP, RPM and price
Elibra / Hovertech
Magnetic levitation
Grainger Industrial Equipment
Electric Motors
RPM, HP and price
Universal Hovercraft
Fans for personal hovercrafts
Northern Tool and Equipment Co.
Gas Motors, price comparison
Functional Benchmarking
Metrics & Corresponding Target ValuesMetrics & Corresponding Target Values
1) Number of Principles Taught - 32) Performance on lab experiment - average score = 80%3) Height of hovering (Object Clearance) - ~6” 4) Skirt to ground clearance - 1/2”5) Speed of Vehicle - 5 - 10 mph 6) Acceleration - 1 mph/s7) Directions of Horizontal Travel - 360 degrees 8) Travel Range - limited by fuel capacity alone9) Turning Radius - 15 ft10) Fuel Efficiency/Capacity - 3 1/2 hrs11) Cost - $200012) Weight - 1000 lbs.
Concept Generation & Evaluation Against MetricsConcept Generation & Evaluation Against Metrics
Education & Recreation1) Smithsonian Approach: use a video or descriptive poster to
explain the principles to the children2) Amusement Park Approach - just let children operate it
and then attempt to explain how it works
Operation1) Means of Lift: 2) Power Supply: 3) Thrust
Magnetic Levitation Electric Engine/Fan Fan(s) and Air Cushion Liquid Fuel Human Power
Suspension Fuel Cells Rocket Thrust
What are the different aspects of our project? Education, Operation, Recreation
How can we satisfy our mission statement in various ways?
Concept Generation & Evaluation Against MetricsConcept Generation & Evaluation Against Metrics1) With regard to Education & Recreation:
- Choose Smithsonian Approach:
- videos and posters allow for easy explanation
2) With regard to Operation:
- Choose a fan/motor lift and thrust system
- Magnetic Levitation = too expensive
- Suspension System = too bulky, doesn’t demonstrate hovering principles
- Human Power for thrust is a viable alternative
- Choose Liquid Fuel:
- engines are relatively inexpensive
Doesn’t demonstrate appropriate principles
Choose: Fans and Air Cushion
swgzVP
gzVP
−++=++ 2
222
1
211
22 ρρSteady-Flow Energy Equation
Concept Selection: Mathematical Models (Lift)
3
233
2
222
22gz
VPgz
VP++=++
ρρBernoulli’s Equation
3
3
)()(2
lw
WwlmwW weight
sρ
+=
=
⟨⟨
ρAweight
ws=
Concept Selection: Mathematical Models (Lift)
ρ2
3
2PV =
lw
WwlAVQ weight
perimeter ρ2
)(23 +==
Qm ρ=⟨
lwA=
From Energy Equation:
From Bernoulli’s Equation:
Figure 2 : Gap Height = 1.5cm
Figure 3 : HP = 8
lw
W
A
WP weightweight ==
og
WM =
MaF =a = 1.5 ft/s2 (from Metrics)
go = 32.2 ft/s2 (from Metrics)
Thrust Force Required = 60lbs.
Concept Selection: Mathematical Models (Lift & Thrust)
W = 1000lbs. (from Metrics)
lw
W
A
WP weightweight ==
Pressure Required = 0.116 psi
l = 10 ft
w = 6 ft
W = 1000lbs. (from Metrics)
Final Concept SelectionFinal Concept Selection
1) Educational Poster (education) a) Discusses uses of Hovercraft as it relates to the Delaware Aerospace Academy b) Discusses Construction Design c) Explains principles of:
- Lift- Thrust
2) Laboratory Experiment (education)- Students learn about lift first hand- Hands on approach similar to Smithsonian museum
3) Prototype Hovercraft Demonstration (fun)- Students get to operate a working hovercraft
Hovercraft Specs.Shape: Rectangular (10’ x 6’)
- most stable - ease of construction
Fan SystemLift - 8 hp lift engine - 4 blade 26” diameter fanThrust - 3.5 hp thrust - 2 blade 34” diameter fan
Weight- empty weight of 450 lbs.
VIDEOVIDEO
1) Hovering Capability 4) Time it takes craft to settle after
Weight Skirt to ground clearance shutting engine offJust Craft Trial 1 Trial 2 Trial 3 Average Time
50 lbs. 6" 6" 6" 6" Trial # 1 pilot 2 pilots100 lbs. 6" 6" 6" 6" 1 1 sec. 1 sec.150 lbs. 5.8" 5.5" 5.75" 5.68 2 1 sec. 1 sec.200 lbs. 5.75" 5.6" 5.5" 5.62 3 1 sec. 1 sec.250 lbs. 5" 5.25" 5" 5.08 4 1 sec. 1 sec.300 lbs. 4.25" 4.33" 4.2" 4.26 5 1 sec. 1 sec.
* We found that as soon as the engine
2) Approx. angle of hover is cut, the craft settles down on itsWe found that getting the craft to hover flat is just a matter skids pretty quickly. It is not so suddenof balancing it. With two pilots of relatively equal weight, as to deter from the safety of the craftthe craft hovers almost exactly horizontal.
5) Stability
Height of OscillationsSmall to nothing. With the throttle in one position,
3) Amount of time from when the engine the craft will hover at a constant height
starts until it is hovering
Time 6) Does the craft hover in place or doesTrial # 1 pilot 2 pilots it tend to go in a certain direction?
1 2 sec. 3 sec. This depends on two factors: wind and terrain.2 3.5 sec. 3.5 sec. On perfectly flat ground with no wind, the craft3 4 sec. 2.5 sec. hovers in place. With hills and wind, the craft 4 2.5 sec. 2 sec. tends to move. 5 2.5 sec. 3 sec.
* Basically, the time it takes the craft fully rise 7) Do we have to adjust the skirt each time
depends on how the pilot operates the throttle. we start it or will it hover by simply starting the fan?The hovercraft will rest on the skids so thatthe skirt does not have to be adjusted each time. It can simply be started up again.
Lift Test Results
Test Results: EducationTest Results: Education
Lab:– Experiment and laboratory model brought into
classroom and demonstrated to a class All students were overwhelmingly enthusiastic
about the lab and interested in the hovercraft
Students demonstrated understanding of principles
by discussing them
Students wanted to build their own model
“hovercrafts”. Asked how to build one
Modifications
Thrust Fan Replacement
Add collar to Lift Motor Shaft
Apply protective screens prior to delivery
Add ballast to the front of craft
Recommendations Safety
– Eye and Ear protection for pilots and operators– Familiarization of Safety manual– Run only under adult supervision– Perform safety check before and after operation
Maintenance– Familiarization of Operation manual– Check skirt for holes and tears
Budget
Materials (Wood, Hardware) - $ 734.45 Lift fan, Skirt, Hub - $ 361.22 8hp Lift Engine - $ 358.70 Thrust Fan - $ 157.00 3.5hp Thrust Engine - $ 167.99
TOTAL: $1779.36
Development and Fabrication Time
Engineering Concept Development– 110 hours
Fabrication– 610 hours
Redesign and Modification– 20 hours
TOTAL: 740 hours