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Airship fo shizzle

Jon AndersonTeam Lead

Hours Worked: 118

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Team Member

Jon Anderson

Agenda

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Outline:• Vehicle selection – Military Decision Making Process (FM 101-5)• Airship Design• Airship Performance• Deployment• Enabling technologies• Recommendation and conclusion• Questions

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Problem

• Determine which aero-vehicle or combination of aero-vehicle would be best suited for a mission to Titan.

• Apply Military Decision Making Process

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Recommendation

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Facts

• Vehicle must be able to land.• Vehicle must be able to carry the given science instrument payload.• Vehicle must have some means of self propulsion.• Only a helicopter-airship combination will be evaluated.

• Most heavily researched options.

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Assumptions

• All designs can survive atmospheric conditions• All designs can be packaged into a 3 m diameter aero shell• All designs will operate within 0-5 km of the surface

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Courses of Action

Helicopter

Airship

Tilt-Rotor

Airplane/Glider

Helicopter/Airship combination

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Screening Criteria

• Vehicles must have some basic research done from other sources.• Can’t design vehicles from nothing

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Evaluation Criteria

Mass – Lower is better

Pre Designed Level – Higher is better

Operational Life time – Longer is better

Top Speed – Higher is better

Redundancy – 0 if not available, 1 if available

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Weighing Criteria

Pre-designed Level – 10%

Mass – 25%

Operational Life time – 15%

Top Speed – 10%

Redundancy – 40%

Assign 1,2,or 3 with 1 being the best in that category

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Analysis – COA screened out

Tilt rotor

Airplane/Glider

Lack of information

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COA - Airship

Mass – 490 kg

Pre Designed Level - High

Operational Life time – 150 Days

Top Speed – 3.5 m/s

Redundancy - None

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COA - Helicopter

Mass – 290 kg

Pre Designed Level - low

Operational Life time – 120 Days

Top Speed – 4.5 m/s

Redundancy - None

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COA - Combination

Mass – UNK – Assume largest

Pre Designed Level – Medium

Operational Life time – 120 Days

Top Speed – 3.5 m/s

Redundancy - Yes

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Information Presentation

Took COA

Applied weighing criteria

Assigned number values based on 1 as the “best” and 3 being the “worst”

Tallied findings in a table

Example calculation for combination values:• Mass - highest mass – scored 3, weight 10%, score = .3• Pre-design level – second highest – scored 2, weight 10%, score = .2

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Analysis Continued - Airship

Mass (10%)

Pre-design level (10%)

Life time (15%)

Speed (15%)

Redun. (50%)

Total

Airship .20 .1 .15 .30 .5 1.25

Helicopter .10 .3 .3 .15 .5 1.35

Combination

.30 .2 .3 .30 0 1.10

Overall Total score – Lower is better

Combination is the recommended COA

Through research – divided mission of science and communication to save on overall mass.

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Airship Design

Jon Anderson

Mission Goal: The primary mission of the airship is to function as a relay between the orbiter and the helicopter. The secondary mission of the airship is to function as a reserve platform capable of carrying out the science mission should the helicopter become inoperable.

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Design Constraints

Jon Anderson

• Communication payload• Extra redundancy – orbiter and helicopter

• Science payload

• Power subsystem• MMRGT

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Assumptions

Jon Anderson

Mass Assumption:

• Needed initial estimate for mass of hull and structural components

• Found fraction of weight for non-hull components vs NASA• Estimated initial weight

• Designed airship, calculated final mass

• Reiterated process with calculated mass

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Equations

Jon Anderson

Vm

TR

Mp

VgB

atm

atmHe

AirshiptianHeatm

)(

2

2

1

22

222

2

1

cos

56

10312

1:4,3

4

ab

ab

r

rb

bbabrbS

abV

Buoyancy and Volume equations:

Shape and Surface Area equations:

Sources:5. Wolfram: The Mathematica Book, Wolfram Media, Inc., Fourth Edition, 1999 6. Gradshteyn/Ryzhik: Table of Integrals, Series and Products, Academic Press, Second Printing, 1981

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Equations

Jon Anderson

)2(2

1

302.1252.172.

,3/22

6/1

2.13/1

,

bVR

CVUD

R

ld

ld

dl

C

e

HullDVHull

e

HullDV

Drag and Reynolds number equations:

Thrust and power available equations:

fowardrequired DUPower

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Diagram of Airship

Jon Anderson

Length 13.83 m

Width 3.45 mVolume 34.47 m^3Ballonet volume 8.96 m^3

Fins 1x1x.7 m

Gondola .7x.7x1.63 m

20% Margins

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Reynolds # and Drag vs Velocity

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Power Required/Available vs Velocity

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Inflation time/percent vs Lift

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Performance

Jon Anderson

Mass 195 Kg

Operational Cruse Velocity 2.5 m/s

Max Velocity 2.98 m/s

Min Climb/Descent Rate * 50 m/min

Range 36200 km

Service Ceiling 5 km

Absolute Ceiling 40 km

Estimated Lifetime * 150 days

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Deployment

Jon Anderson

Airship inflation immediate

• Both bayonets and main envelope

• Changing ballistic coefficient

• Separate via explosive shearing bolts • Immediately max velocity

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Enabling Technologies

Jon Anderson

Multi Mission Radioisotope Thermal Generator

• Complicated – beyond scope of design

• 5 fold increase in power• Lower mass

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Recommendation and Conclusion

Jon Anderson

High Altitude Design

Detailed data bandwidth analysis

Hull/system optimization

Experments

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Questions?

Jon Anderson

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Backup slides - Mass

Jon Anderson

Component Mass (kg) Mass after 20% Margin (kg)Subsystem

Power 2nd Generation MMRTG 17 20.4Battery - 12 A h lithium 0.47 0.564Turbomachinery 3.94 4.728Turbine 0.9 1.08Compressor 0.9 1.08Piping 0.716 0.8592Electric Motor 1.08 1.296Alternator 1.08 1.296

Total 26.086 31.3032

Propulsion Propeller, axel, case* 5.25 6.3

Total 5.25 6.3

Science Instruments Haze and Cloud Partical Detector 3 3.6Mass Spectrometer 10 12Panchromatic Visible Light Imager 1.3 1.56

Total 14.3 17.16

Communication X-Band Omni - LGA 0.114 0.1368SDST X-up/X-down 2.7 3.24X-Band TWTA 2.1 2.52UHF Transceiver (2) 9.8 11.76UHF Omni 1.5 1.8UHF Diplexer (2) 1 1.2Additional Hardware (switches, cables, etc.) 6 7.2

Total 23.214 27.8568

ACDS Sun Sensors 0.9 1.08IMU (2) 9 10.8Radar Altimeter 4.4 5.28Antennas for Radar Altimeter 0.32 0.384Absorber for Radar Altimeter 0.38 0.456Air Data System with pressure and temperature 5 6

Total 20 24

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Backup slides - Mass

Jon Anderson

C&DH Flight Processor 0.6 0.72

Digital I/O - CAPI Board 0.6 0.72

State of Health and Attitude Control 0.6 0.72

Power Distribution (2) 1.2 1.44

Power Control 0.6 0.72

Mother Board 0.8 0.96

Power Converters (For Integrated Avionics Unit) 0.8 0.96

Chassis 3.4 4.08

Solid State Data Recorder 1.6 1.92

Total 10.2 12.24

Structure Airship Hull 4.57 5.484

Gondola* 8.4 10.08

Tail Section: 4 Fins and attachments* 8.4 10.08

Attitude Control 4 4.8

Helium Mass (Float at 5 km) 29.95 35.94

Inflation tank for Helium* 19.17 23.004

Bayonet fans and eqipment 5.5 6.6

Total 79.99 95.988

Thermal Inflight and during operation 8.27 9.924

Total 8.27 9.924

Total Airship Dry Mass 187.31 224.772

Total Aiship Float Mass 217.26 260.712

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Backup slides

ComponentPower Required (W)

Power Required after 20% Margin (W)

Subsystem

Power 580 W Generated

Proplusion Propeller/Engine See Figure 2 See Figure 2

Total See Figure 2 See Figure 2

Bayonets Fans (2) 90 108

Total 90 108

Science Instruments Haze and Cloud Partical Detector 20

Mass Spectrometer 28Panchromatic Visible Light Imager 10

Total 58 69.6

Communication UHF Transceiver 74.88

Total 74.8 89.76

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Backup slides - Power

Jon Anderson

ACDS* Sun Sensors 0.56IMU 22.2Radar Altimeter 37.6Air Data System with pressure and temperature 7.72

Total 68.08

C&DH* Flight Processor; >200 MIPS, AD750, cPCI 11.6Digital I/O - CAPI Board 3.44State of Health and Attitude Control - SMACI 3.44Power Distribution 6.88Power Control 3.44Power Converters (For Integrated Avionics Unit) 13.84Solid State Data Recorder 0.64

Total 43.28

Total Power Required without proplusion with all systems operating - Straight and level 244.16

Total Power Available for Propulsion - Straight and level 335.84