New Castle Design Associates

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TEAM 12Composite Generator Enclosure

• New Castle Design Associates
• PROJECT 99.12

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Composite Generator Enclosure

• Team 12

• Justin Schaffer
• Tom Winward
• Noel Goldstein
• Jeremy Freeman

Members

• Partner

Center for Composite Materials

• Advisor

Dr. Michael Keefe

• Mission

It is our goal to design and construct a
prototype portable generator enclosure made from
composite materials that successfully satisfies
all the wants and constraints defined by our
customers, and to have a prototype built by April
1999.

• Approach

We will first identify customers and their wants.
We will also attempt to find all current
technology in use for sound reduction and in the
area of composites. Then concepts will be
developed based on the information gained during
our benchmarking. The best design will be
determined by comparing our concepts with
customer wants and constraints. Next we will
begin a process of prototype design and
evaluation, culminating with the production of a
prototype part. This prototype is then to be
further developed by CCM to fit the D Star
generator.
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Background

• Army needs portable generator for use in remote
  locations
• D-Star Engineering designing lightweight, high
  power diesel generator
• Team 12 to design a prototype enclosure
• CCM to finish development for pre-production model

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Customers

• D-Star Engineering
• U.S. Army
• New Castle Design Associates
• Safety Organization (NFPA)
• Army Soldier
• Home Owners
• Construction Industry
• Outdoor Entertainment
• RV Owners
• Emergency Services

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Wants and Constraints
Wants

• Ease of Operation
• Longevity
• Ease of Maintenance
• Cost

• Will not break
• Thermally Stable
• Quiet
• Portable
• Stackable

Constraints

• 15 x 16 x 30
• 25 LBS
• Composites

• Maximum Size
• Maximum Weight
• Primary Materials

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Benchmarking

• System Level
• Open Tubular Frame
• Westerbeke Clamshell Enclosure
• Honda Super Quiet Generators
• Fisher Panda Generators
• Previous UD NCDA Enclosure

• Functional
• Sound Suppression
• Accessibility
• Ventilation/Heat Rejection
• Stackable
• Rolling
• Carrying
• Weather Exposure
• Ease of Starting

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System Level Best Practices

• Years of Exposure Painted Metal
• Tg N/A
• Weight Open Frame
• Cost Open Frame
• Sound Level Enclosed Box
• Drop Test ?
• Stackable N/A
• Time to Access Open Frame
• Time to Start Electric Start

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Metrics and Target Values

• Years of Exposure 10 yrs / 3000 hrs
• Tg 350F / 800F
• Weight 25 lbs
• Cost 200
• Sound Level 60 dB / 65 dB max
• Drop Test 4 ft
• Stackable 5 units high
• Time to Access 10 min
• Time to Start 1 min

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Physical Model Testing1

• Sound Testing
• Temperature Testing

• Unenclosed/ Enclosed Generator
• Load/ No Load

• Enclosed
• Forced Convection

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Physical Model Testing2
...The Equipment
Sound Test...
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Critical Concepts
Wants
Concepts

• Stackable
• Access to interior
• Portable
• Quiet, Longevity, Cost, Will not break, Thermally
  stable

• Rectangular
• Panels (removable, hinged, sliding)
• Handles, Wheels
• Composite sandwich

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Concepts1
Hand Buggy Style with 6 removable access
panels Advantages Easy Access and
Mobility DisadvantagesNot Structurally Sound
Clam Shell Design with 4 Dolly
wheels Advantages Easy to Roll on smooth
surfaces, Easy Access Disadvantages Large Stress
Concentrations
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Concepts2
Multiple roller wheels and Sliding Side Door
Access Advantages Easy to Use Disadvantages
Limited Access and difficult outdoor mobility
2 Piece Shell Access Advantages Easy to
Use Disadvantages High Stress on Latches
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Concept Selection

• Mobility
• Access
• Composite Structure

• Hand Buggy Style
• with Additional Handle
• Multiple Panels at Critical Locations
• Ciba Resinfusion 8605 Epoxy,
• E-Glass and Kevlar Fibers,
• Phenolic Foam Core

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Composite Structure Selection

• Phenolic Foam Core did not hold up structurally
  in initial sample tests
• Further research led to the testing of a Balsa
  Wood Core

Kevlar 49
Kevlar 49
Phenolic Closed Cell Foam Core
Balsa Wood Core
CIBA RESINFUSION 8607
E-Glass
E-Glass
S.C.R.I.M.P.
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Composite Lay Up2
Test Samples
3 Point Bend Test
Drop (Impact) Test

• Samples made and tested with varying numbers of
  layers of fabric around balsa wood core

• Best Lay Up 2 layers of Kevlar 49, and 2 layers
  of E Glass.

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Final Concept
3 Recessed Handles
Removable Top Panel
Recessed Wheels
Hinged Starting Panel
Kevlar 49 (2), Balsa Wood, E-Glass (2) Sandwich
Structure
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Concept Testing1

• Sound Reduction
• Maximum 64.5 dB sound level in open parking lot,
  measured at 7m.
• Temperature
• 160-170 oF inside
• Size
• 15x16x30
• Weight
• 22 Pounds without louvers, handles and wheels
  (These will add approximately 8 pounds)

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Concept Testing2

• Drop Test
• 4 ft. Off loading dock onto asphalt sustained
  only minimal damage
• Access Time
• 30 sec. to remove starting door, and replace
• 5 min. to remove top cover to access engine and
  replace
• Stackable
• Supported 400 pounds on top

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Prototype Budget

• Materials
• MOLD
• Wood Miscellaneous (including Bondo Body
  Filler, Paint, Sand Paper, Screws, etc)
• SCRIMP
• Ciba Resin
• Kevlar
• E Glass
• Phenolic Foam
• Balsa Wood
• SCRIMP Materials (including Vacuum Bag, Tubing,
  Tacky Tape, Peel Ply, Distribution Medium)
• OTHER
• Film and Developing
• Decibel Meter
• TOTAL

• Team Cost
• 399.68
• 0.00
• 105.00
• 671.25
• 181.30
• 414.00
• 167.51
• 30.00
• 30.00
• 1,998.74

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Est. Engineering Shop Hours

• Fabrication
• Wooden Model...16
• Mold..400
• Test Panels..60
• SCRIMP200
• Finishing..15
• Testing...6
• TOTAL..697

• ResearchDevelopment
• Benchmarking...40
• Customers/Wants..20
• Foam Core Design....40
• Balsa Core Design....70
• Shape....65
• Matl Procurement20
• TOTAL...255

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Projected Production Costs

• Kevlar
• E-Glass
• Balsa Wood
• Resin

• 4 yards
• 3 yards
• 3 1/2 sheets
• 1 gallon

• 70.00
• 16.11
• 41.40
• 73.93

• Total 201.44

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Conclusion
Our final design has met and exceeded most wants
and constraints placed by our customers. Areas
for improvement include decreasing the weight and
using a better method to lay-up the composite
fabrics.