Team Members:Brandon FicheraDave RabenoGreg PeaseSean Gallagher

Sponsor:Dr. Stephanie WrightDelaware 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 principlesChoose: Fans and Air Cushion

swgzVPgzVP−++=++ 2

222

1

211

22 ρρSteady-Flow Energy Equation

Concept Selection: Mathematical Models (Lift)

3

233

2

222

22gzVPgzVP

++=++ρρ

Bernoulli’s Equation

3

3

)()(2

lwW

wlmwW weights

ρ+=

=

⟨⟨

ρAweightws=

Concept Selection: Mathematical Models (Lift)

ρ2

32PV =

lwW

wlAVQ weightperimeter ρ

2)(23 +==

Qm ρ=⟨ lwA=

From Energy Equation:

From Bernoulli’s Equation:

Figure 2 : Gap Height = 1.5cm

Figure 3 : HP = 8

lwW

AW

P weightweight ==

ogWM =

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)

lwW

AW

P 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 off

Just Craft Trial 1 Trial 2 Trial 3 Average Time50 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) StabilityHeight 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 hoveringTime 6) Does the craft hover in place or does

Trial # 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

Projected Production Costs

Total Material Costs:– $1779.36

Estimated Production Hours:– 200 hours– $25/hr

Projected Cost = $5000 + $1779.36 = $6779.36