Download 9_Balta_Jerald_Prop5 - Purdue College of Engineering

Jerald A. Balta
3/27/2008
Propulsion Team/CAD
Final Slides
AAE 450 Spring 2008
Balloon Cost Modifier
 Balloon Cost Items
– Balloon – Price quote from Aerostar International
– Helium – Priced at $4.87 per cubic meter
– Gondola- Constant Price of $13205.30
Balloon
Helium
Gondola
Total
200g case
82,007.00
14,813.00
13,205.30
110,025.30
1 kg case 5 kg case
60,848.00 157,070.00
10,644.00 32,979.00
13,205.30 13,205.30
84,697.30 203,254.30
AAE 450 Spring 2008
Balloon Cost
Cost Trend Equation
 y = -0.0011x2 + 30.62x +
3111.1
 y= Cost
 x=Balloon Payload
120000
100000
Cost (dollar)
Payload Payload
Mass(lbm Mass(kg Cost
500
226.8 $10,000
2000 907.18 $30,000
8000 3628.7 $100,000
80000
60000
40000
20000
AAE 450 Spring 2008
0
0
1000
2000
3000
4000
Payload Mass (kg)
3<#>
Balloon Model
Buoyancy
 Free Body Diagram
 Two forces acting on
Spherical Balloon
– Buoyancy Force
• Defined by difference
between masses of
lifting gas and air
multiplied by
gravitational constant
– Weight
Weight
Cl   a   g
Derivation of Balloon Dimensions
 Lifting Coefficient
– Ρg is density of lifting
gas
– Ρa is density of air
 Boyle’s and Guy Sac
laws
– Rho is density
– P is pressure
– T is Temperature
Cl   a   g
 P T0

0 P0 T
Cl ,0 

*C
0 l
Derivation of Balloon Dimensions Continued
 Combine Equations to
determine lifting
coefficient for different
heights
 Take into account 95%
Gas purity and standard
excess of 15% lifting gas
 Final Equation for Volume
of Gas in relation to Mass
– V is Volume of lifting gas
– M is total Mass

Cl ,0 
* Cl
0
Cl , F  0.85*0.95* Cl ,0
Cl , F *V * g  M Total * g
Gondola Costs
•Structures Cost of $1205.30
•Material
•Welding
•Riveting
•Avionics Cost of $12000
•One Battery
•Sensors
Total Gondola Cost of $13,205.30
Provided by Sarah Shoemaker, Structures Group, and Avionics Group
Ground Support and Handling Cost Modifier
 Handling – Personnel required for handling of
fuels, toxic materials, etc
 Ground Support – Based on estimation of
salaries of necessary personnel
– Assumed $100/hour salary
– 6 engineers from all teams and one manager
Cost Modifier
Stage 1
200g case 1 kg case 5 kg case
Handling
2000
2000
2000
Ground Support 14000
14000
14000
Total
16000
16000
16000
Stage 2
Handling
8000
8000
8000
Ground Support 14000
14000
14000
Total
22000
22000
22000
Stage 3
Handling
8000
8000
8000
Ground Support 14000
14000
14000
Total
22000
22000
22000
References
 Defense Energy Support Center, “MISSILE FUELS STANDARD
PRICES EFFECTIVE 1 OCT 2007,” Aerospace Energy Reference,
November 2007
 Larson, W.J., Wertz, J.R., "Space Cost Modeling," Space Mission
Analysis and Design, 2nd ed., Microcosm, Inc., California and
Kluwer Academic Publishers, London, 1992, pp. 715-731.
 Smith, Mike, Phone Conversation, Aerostar International, February
15, 2008
 Tangren, C.D., "Air Calculating Payload for a Tethered Balloon
System," Forest Service Research Note SE-298, U.S. Department
of Agriculture - Southeastern Forest Experiment Station, Asheville,
North Carolina, August 1980.