4 Spheres4 Spheres33

PresentsPresents

The Development of Gus™The Development of Gus™

ObjectivesObjectives

Reliability, stability and controllabilityReliability, stability and controllability Most efficient battery usage possibleMost efficient battery usage possible Clarify design ambiguitiesClarify design ambiguities Scare oppositionScare opposition Have a sufficiently more professional Have a sufficiently more professional

appearance than at the PDRappearance than at the PDR

Gus™Gus™

Gus™Gus™

Final Design EvolutionFinal Design Evolution

Small motor deemed unnecessarySmall motor deemed unnecessary Corner support beams addedCorner support beams added Servo gear system replaced with Servo gear system replaced with

pulley systempulley system Simplified central post structureSimplified central post structure

• Aluminum deemed unnecessaryAluminum deemed unnecessary• Truss structure abandonedTruss structure abandoned

Final Design - Gus™Final Design - Gus™

Final Design - Gus™Final Design - Gus™

Balloon stabilityBalloon stability SymmetrySymmetry

• Vehicle StabilityVehicle Stability• No control surfacesNo control surfaces

Simple constructionSimple construction Modular TopModular Top Bulky, but lightBulky, but light

Dimensions and LayoutDimensions and Layout

Top View 3D View

Dimensions and LayoutDimensions and Layout

Weight AnalysisWeight Analysis

Balsa Wood FrameBalsa Wood Frame 188g188g

4 Balloons @ 70g4 Balloons @ 70g 280g280g

Receiver/Antenna/ServoReceiver/Antenna/Servo 28g28g

2 Motor & Speed Control @ 120g2 Motor & Speed Control @ 120g 240g240g

2 Propellers @ 5.5g2 Propellers @ 5.5g 11g11g

Mechanical LinkMechanical Link 10g10g

Engine Mount “T”Engine Mount “T” 15g15g

WiringWiring < 10g< 10g

Battery PackBattery Pack 110g110g

TOTALTOTAL 892g892g

Aero AnalysisAero Analysis Helium Vol.Helium Vol.

• Max. Vol. = Max. Vol. = 2.094 m2.094 m33

• Req. Lift = 8.75NReq. Lift = 8.75N = (.892 kg)(9.81 m/s= (.892 kg)(9.81 m/s22))• V = W/[(V = W/[(ρρairair – – ρρHeHe)g])g]

= = 0.853 m0.853 m33 Vehicle ThrustVehicle Thrust

• 2 large motors yield 2 large motors yield 1.76N thrust1.76N thrust

Vehicle DragVehicle Drag• CCDD estimated at estimated at 0.950.95• D = (½)(D = (½)(ρρairairvv22)(S)(C)(S)(CDD) = ) = (½)(½)

(1.22)(v(1.22)(v22)(1.57)(.95))(1.57)(.95) = = 0.9098v0.9098v22

Vehicle VelocityVehicle Velocity• V = thrust/(½CV = thrust/(½CDDS)S)½½ = = 2.04 2.04

m/sm/s• S = 2(pi)(.5)S = 2(pi)(.5)5 5 =1.57 m=1.57 m22

Flight DurationFlight Duration• Ideal = d/v = 87.78/2.04 = Ideal = d/v = 87.78/2.04 =

43 sec.43 sec.• Excludes deceleration due Excludes deceleration due

to turning and to turning and disturbances in airflow.disturbances in airflow.

• Realistic = Realistic = 120 sec120 sec• Max battery life = Max battery life = 10 10

minsmins

ElectronicsElectronics

Control SystemControl System

ScheduleScheduleMon. Tue. Wed. Thur. Fri. Sat. Sun.

14 15 16 17 18 19 20

Vehicle Construction CDR preparations

21 22 23 24 25 26 27

rehearse CDR: CDR

28 29 30 1(May) 2 3 4

Construction Setup Electronics

5 6 7 8 9 10 11

Trial Tune/Repair/improve vehicle

12 13 14 15 16 17 18

RACE DAY! THE END

ConclusionConclusion

After analysis and testing, we have After analysis and testing, we have certified that Gus™ is on the runway certified that Gus™ is on the runway of life. We hope that his potential to of life. We hope that his potential to be a reliable, stable, and efficient be a reliable, stable, and efficient lighter-than-air vehicle will lead to lighter-than-air vehicle will lead to success. See you on trial day.success. See you on trial day.