Power, Propulsion, and Thermal Design...
56
Power, Propulsion, and Thermal Design Project Doug Astler Leah Krombach Calvin Nwachuku Andrew Will
Transcript of Power, Propulsion, and Thermal Design...
Power, Propulsion, and
Thermal Design Project
Doug Astler
Leah Krombach
Calvin Nwachuku
Andrew Will
Mission Specifications
• 10 day mission with 3 contingency days
o 3 days to Moon
o 4 days on Moon
o 3 days to return to Earth
• Gross mass of 4795 kg
• Design a reaction control system
o 6 degree of freedom control
o ∆V of 50m/s
o Hold altitude in dead band
o Overcome entry aerodynamic moments
o Rotate 180 degrees in less than 30 seconds
Team B3 2 Power, Propulsion and Thermal Design
ENAE 483
Mission Specifications Cont.
• Design a power system
o Provide power to spacecraft
o Support all mission phases
• Design thermal control system
o Radiator temperature
o Radiator size
o Radiator location
o Maintain cabin temperature during all mission
phases
• Choose design from crew system design project
Team B3 3 Power, Propulsion and Thermal Design
ENAE 483
Outline
• Selecting a Design
• Coordinate System
• Propulsion
o Dead Band Control Algorithm
Attitude Trajectories in the Phase Plane
Phase Plot of Reaction Control System
Duty Cycle vs Tau/I
o Dead Band Control Thrust
o Reentry Control
o Cold-gas Thruster
o Propellants for Cold-gas Thruster
Thrust vs Area
Mass vs Gas Type
Volume vs Gas Type
Team B3 4 Power, Propulsion and Thermal Design
ENAE 483
Outline Cont.
o Cold-gas Reaction Control System
o Nitrogen Mass Breakdown
o Thrusters Structure and Location
o Reaction Control System
• Power System
o Solar Cells
o Radioisotope Thermoelectric Generators
o Batteries
o Fuel Cells
o Power Trade Study
Mass vs Time
Volume vs Power
Team B3 5 Power, Propulsion and Thermal Design
ENAE 483
Outline Cont.
• Thermal
o Temperature of Environment
o Internal Temperature Calculations
o Internal Cabin Temperature Without External Radiator
o Temperature Control
o Temperature vs. Emissivity in LLO Eclipse
o Selection of Emissivity
o Radiator Sizing
o Temperature of External Radiator vs. Area of External Radiator
o Selection of Radiator
o Final External Radiator Temperature
o Radiator Mass (Aluminum)
• Total Mass and Volume
• CAD
Team B3 6 Power, Propulsion and Thermal Design
ENAE 483
Selecting a Design
Name Power (Watts) Mass (kg)
Leah 443 1,331
Doug 839 1,352
Calvin 421.3 1,340.8
Andrew 1,126.6 1,303.1
Fig 1. Power vs Mass Considerations from Previous Design
Team B3 7 Power, Propulsion and Thermal Design
ENAE 483
Selecting a Design Cont. • Picked Andrew's team design (A4)
• Lowest value of mass
• Highest value of power required
o Team A4 considered power required for:
E.D.C CO2 scrubbing
Trace Contaminants Control
Water Distillation
Dehumidifier
O2, N2 and H2 Storage
o Picked highest value of power
Took into account the most systems requiring power
Safer to over design for max power
Team B3 8 Power, Propulsion and Thermal Design
ENAE 483
Coordinate System
• Right hand
system
• Y direction points
into the page
• Origin at the
center of mass
Fig 2. Coordinate System
Team B3 9 Power, Propulsion and Thermal Design
ENAE 483
Propulsion System
Team B3 10 Power, Propulsion and Thermal Design
ENAE 483
Propulsion
• Cold-gas system
• Analyzed dead band for our spacecraft to find duty
cycle and thrust required
• Analyzed thrust required for aerodynamic moment
• Analyzed thrust required for roll on reentry
• Nitrogen was chosen as the propellant
Team B3 11 Power, Propulsion and Thermal Design
ENAE 483
Dead Band Control Algorithm
• Zero thrust o Theta varies between -10 and 10 degrees
o Theta dot varies between -0.8 and 0.8 degrees per
second
• Negative Thrust
o Falls below dead band
• Positive Thrust
o Rises above dead band
Team B3 12 Power, Propulsion and Thermal Design
ENAE 483
Fig 3. Phase Plot of Spacecraft Under Different Torques [1]
Team B3 13 Power, Propulsion and Thermal Design
ENAE 483
Fig 4. Simulation of Dead Band Algorithm With Initial Angular Displacement and Velocity
Team B3 14 Power, Propulsion and Thermal Design
ENAE 483
Fig 5. Duty Cycle vs. Torque Over Moment of Inertia for Dead Band Algorithm
Team B3 15 Power, Propulsion and Thermal Design
ENAE 483
Dead Band Control Thrust
• As the previous slide indicates
o Lowest duty cycle is 0.005
o Occurs at a torque over moment of inertia of 0.0011s-2
• Important Constants needed
o Ixx = Iyy = 8.33x103 kgm2
o Izz = 1.12x104 kgm2
o Moment Arm = 1.34 m
• For the X and the Y direction and using Tau/I = .0011 the
thrust required is 3.37 N
• For the Z direction and using the same Tau/I the thrust
required is 4.6 N
Team B3 16 Power, Propulsion and Thermal Design
ENAE 483
Reentry Control
• Overcome 500 Nm in pitch and yaw
o Centroid of thrusters aligned with center of mass
Moment arm of 1.34 m
o 500𝑁𝑚 = 2𝑇 ∗ 1.34𝑚 where T is thrust
o T = 186.57 N
• Rotate 180 degrees in 30 seconds
o Same thrust as pitch and yaw thrusters
o T=186.57 N
o Izz = 1.12x104 kgm2
o1
2
𝜏
𝐼𝑡2 = 𝜋
o t=5.93 seconds Team B3 17 Power, Propulsion and Thermal Design
ENAE 483
Cold-gas Thruster
Fig 6. Schematic of a Cold-Gas Rocket System [2]
Team B3 18 Power, Propulsion and Thermal Design
ENAE 483
Propellants for Cold Gas Thruster
Propellant Molecular Mass Density (lb/ft3) Isp (sec)
Hydrogen 2 1.21 296
Helium 4 2.37 179
Methane 16 12.1 114
Nitrogen 28 17.37 80
Air 28.9 19.3 74
Argon 39.9 27.6 57
Krypton 83.8 67.2 39
Freon 14 88 60.01 55
Fig 7. Properties of Propellants Used in a Cold-gas Thruster [3]
Team B3 19 Power, Propulsion and Thermal Design
ENAE 483
Fig 8. Thrust vs Area for a Cold-gas Rocket System for varying propellants
Team B3 20 Power, Propulsion and Thermal Design
ENAE 483
Fig 9. Reaction Control System Total Mass vs. Species of Gas
Team B3 21 Power, Propulsion and Thermal Design
ENAE 483
Fig 10. Reaction Control System Total Volume vs. Species of Gas
Team B3 22 Power, Propulsion and Thermal Design
ENAE 483
Cold-gas Reaction Control System
• Nitrogen was chosen for the reaction control system
o Total Mass (including tank) = 439.3 kg
o Volume = 1.43 m3
• Able to overcome entry aerodynamic moments
• Supports rotation of spacecraft on reentry
• Three levels of thrust
o Three valve settings
3.37 N
4.6 N
186.36 N
Team B3 23 Power, Propulsion and Thermal Design
ENAE 483
Nitrogen Mass Breakdown
System Nitrogen Mass (kg)
Translational ∆V 296.3
Reentry (Yaw and Pitch) 42.9
Reentry (Roll) 1.4
X-axis Dead Band 20.2
Y-axis Dead Band 20.2
Z-axis Dead Band 29.4
Total Mass 410.4
Fig 11. Mass Breakdown of Propellant
Team B3 24 Power, Propulsion and Thermal Design
ENAE 483
Thrusters Structure and Location
• Four thruster pentads surround the capsule at 90
degree intervals
• Thrusters have five nozzles each 90 degrees from the
others
• Diameter of each thruster is 15 cm
• Centroid of each thruster pentad aligned with capsule's
center of mass
o 96 cm above base of cone
• Thrusters fire in a coupling fashion to achieve purely
rotational or translational motion
o 6 DOF
Team B3 25 Power, Propulsion and Thermal Design
ENAE 483
Thruster Structure
Fig 12. Pentad Thruster Configuration
Team B3 26 Power, Propulsion and Thermal Design
ENAE 483
Power System
Team B3 27 Power, Propulsion and Thermal Design
ENAE 483
Power Systems
Possible Power Systems
• Flywheels
• Magnetohydrodynamic (MHD) Generators
• Solar Cells
• Radioisotope Thermoelectric Generators
(RTGs)
• Batteries
• Fuel Cells
Team B3 28 Power, Propulsion and Thermal Design
ENAE 483
Power Systems Cont.
• Flywheels and magnetohydrodynamic
generators eliminated as possibilities for our
spacecraft
o Flywheels cannot sustain the amount of power
required for the length of the time this mission takes
place [4]
o MHD generators are capable of producing enough
power, but they also cannot sustain that power for
the mission length [4]
Team B3 29 Power, Propulsion and Thermal Design
ENAE 483
Solar Cells
• Use photons from the Sun to power spacecraft
• Opting to consider modern Stretched Lens Array SquareRigger (SLASR)
technology for solar arrays [5]
o Specific Power >300 W/kg [5]
o Areal Power Density >200 W/m2 [5]
o Volume (per unit specific power) 3.33x10-8 m3 [5]
Fig 13. CAD Drawing of Solar Cell [5]
Team B3 30 Power, Propulsion and Thermal Design
ENAE 483
Radioisotope Thermoelectric Generators
• Radioisotope Thermoelectric
Generators (RTGs)
o Long-lived power source
that converts heat into
electricity
o Minimum lifetime of 14
years [7]
o Specific Power
= 2.8 W/kg [7]
o Volume (per unit specific
energy) = 0.0085 m3 [7]
Fig 14. MMRTG Diagram [6]
Team B3 31 Power, Propulsion and Thermal Design
ENAE 483
Batteries
• Li Ion LiMn2O4 battery
packs to provide
electric power
• Specific Energy = 130
Wh/kg [9]
• Volume (per unit
specific energy) =
1.25x10-6 m3 [9]
Fig 15. Li Ion LiMn2O4 Battery Pack [8]
Team B3 32 Power, Propulsion and Thermal Design
ENAE 483
Fuel Cells
• Use methanol-based EFOY 1600-M28 fuel
cells
• Convert chemical energy to electricity
• Specific Energy =
805.1 Wh/kg [10]
• Volume (per unit
specific energy) =
1.24x10-6 m3 [10]
Fig 16. Diagram of Fuel Cell System [10]
Team B3 33 Power, Propulsion and Thermal Design
ENAE 483
Fig 17. Trade Study of Mass vs Time for Power Systems
Team B3 34 Power, Propulsion and Thermal Design
ENAE 483
Fig 18. Trade Study of Volume vs Power for Power Systems
Team B3 35 Power, Propulsion and Thermal Design
ENAE 483
Power System
• Systems not considered o RTG system
Volume exceeds 10 m3 for 13-day mission
o Lithium ion batteries
Mass exceeds 1000 kg for power required
o Solar cells
Present an additional problem of extra surface
area required
Even though most power efficient
Team B3 36 Power, Propulsion and Thermal Design
ENAE 483
Power System
• EFOY 1600-M28 fuel cells were chosen for
this mission o Mass = 518.9 kg
o Power: 839 W (Crew Systems) + ~500 W (Avionics)
= 1339 W
o Maximum Energy: 1339 W x 13 days = 417.8 kWh
o Volume = 0.0835 m3
• All mission phases use the same power
o No dependency on sun
o No dependency on heat
Team B3 37 Power, Propulsion and Thermal Design
ENAE 483
Thermal Control System
Team B3 38 Power, Propulsion and Thermal Design
ENAE 483
Temperatures of Environment
• Space = 4 K
• LEO eclipse = 116 K
• LEO with sun= 280 K
• Lunar Surface [11]
o Polar = 160 K
o 45 degrees Sun= 340 K
o Noon equatorial = 378 K
o Dawn equatorial = 90 K
o Dusk equatorial = 120 K
Team B3 39 Power, Propulsion and Thermal Design
ENAE 483
Internal Temperature Calculations
Team B3 40 Power, Propulsion and Thermal Design
ENAE 483
Internal Cabin Temperature Without
External Radiator LTO - Full Sun Cone Illuminated 371.4 K
LTO - Full Sun Base Illuminated 371.4 K
LEO - Full Sun Cone Illuminated 398.3 K
Eclipse LEO 321.6 K
Eclipse LLO 320.2 K
Lunar Surface Polar 414.0 K
Lunar Surface 45 Degree 434.1 K
Lunar Surface Equatorial Noon 410.1 K
Lunar Surface Equatorial Dawn 371.6 K
Lunar Surface Equatorial Dusk 371.9 K
Max: Lunar Surface 45 Degree 434.1 K
Min: Eclipse LLO 320.2 K
Team B3 41 Power, Propulsion and Thermal Design
ENAE 483
Temperature Control
In order to maintain cabin temperature
• Design spacecraft to have an emissivity to
keep crew warm during the coldest part of the
mission (LLO eclipse)
• Design radiators to dissipate extra heat in the
warmest part of the mission (Lunar Surface)
Team B3 42 Power, Propulsion and Thermal Design
ENAE 483
Fig 19. Trade Study of Temperature vs Emissivity in LLO Eclipse
Team B3 43 Power, Propulsion and Thermal Design
ENAE 483
Selection of Emissivity
• Emissivity between .165 and .173 to keep
the crew at a comfortable temperature
during LLO eclipse
• Absorptance is not a factor because the
spacecraft is not receiving any sunlight
(Qsolar=0)
• Select SiOx on VDA tape for capsule
covering[12]
o Emissivity = .12
o Absorptance = .14 Team B3 44 Power, Propulsion and Thermal Design
ENAE 483
Radiator Sizing
After selecting spacecraft coating
• Determine size of radiators needed by o Hottest location
Lunar surface
o Requirement to maintain cabin temperature at 273K
(room temp)
Team B3 45 Power, Propulsion and Thermal Design
ENAE 483
Fig 20. Trade Study of Temperature vs Area of External Radiator
Team B3 46 Power, Propulsion and Thermal Design
ENAE 483
Selection of Radiator
• Based on the curve a radiator size of 30 m2 was
chosen
• Radiator material chosen is aluminum for its light
weight
• Painted with Z93 white paint for its high
emissivity and low absorptance[12]
o Absorptance = .17
o Emissivity = .92
Team B3 47 Power, Propulsion and Thermal Design
ENAE 483
Final External Radiator
Temperatures Cabin Internal Temperature 293 K
LTO - Full Sun Cone Illuminated 282.9 K
LEO - Full Sun Cone Illuminated 355.3 K
LEO Eclipse 211.7 K
LLO Eclipse 203.8 K
Lunar Surface Polar 249.6 K
Lunar Surface 45 Degree 363.6 K
Lunar Surface Equatorial Noon 391.4 K
Lunar Surface Equatorisl Dawn 205.4 K
Lunar Surface Equatorial Dusk 209.6 K
Max: Lunar Surface Equatorial 391 K
Min: Lunar Surface Eclipse 204 K
Team B3 48 Power, Propulsion and Thermal Design
ENAE 483
15𝑚2 ∗ (100𝑐𝑚
𝑚)2∗ 1𝑐𝑚 = 150000𝑐𝑚3
150000𝑐𝑚3 ∗2.7𝑔
𝑐𝑚3= 405000𝑔
405000𝑔 ∗1𝑘𝑔
1000𝑔= 405𝑘𝑔
Radiator Mass Calculation
(Aluminum)
Volume
Mass
Mass in kg
Team B3 49 Power, Propulsion and Thermal Design
ENAE 483
Radiator Configuration
5 .75mx1m panels (unfolded) Panels fold in for travel to and from moon
Team B3 50 Power, Propulsion and Thermal Design
ENAE 483
Total Mass
System Mass (kg)
Crew Systems 1303.1
Nitrogen Tank 439.3
Radiator 405
Fuel Cells 518.9
Total Mass 2666.3
Total Allotted 4795
Margin 44.4% Fig 21. Mass Allocation
Team B3 51 Power, Propulsion and Thermal Design
ENAE 483
Volume Budget
System Volume (m3)
Initial Volume 6.77
Crew Systems 3.01
Nitrogen 1.34
Fuel Cells 0.84
Remaining 1.58
Margin 23.3%
Fig. 22. Volume Allocation
Team B3 52 Power, Propulsion and Thermal Design
ENAE 483
Team B3 53 Power, Propulsion and Thermal Design
ENAE 483
References
1. Akin, Dave. Lecture 14 PPT/Rocket Propulsion, 2012
2. Zandbergen B.T.C., Modern liquid propellant rocket engines; 2000
Outlook, Internal Publication, Delft University of Technology, Faculty of
Aerospace Engineering, Delft, The Netherlands, March 2000.
3. G.P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons,
1986.
4. Akin, Dave. Lecture 15 PPT/Power Systems Design, 2012
5. O’Neill, Mark, Joe Howell, Louis Lollar, and Connie Carrington.
"STRETCHED LENS ARRAY SQUARERIGGER (SLASR) TECHNOLOGY
MATURATION." N.p., 2007. Web. 7 Nov. 2012.
<http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090022305_20090
22268.pdf>
6. Bechtel, Ryan. U.S. Department of Energy, Nuclear Energy, n.d. Web. 6
Nov. 2012.
<http://www.jpl.nasa.gov/msl/pdf/MMRTG_RyanBechtel_DOE.pdf>.
Team B3 54 Power, Propulsion and Thermal Design
ENAE 483
References Cont.
7. Caponiti, Alice. "Space Radioisotope Power Systems: Multi-Mission
Radioisotope Thermoelectric Generator." N.p., Sept. 2006. Web. 6 Nov.
2012. <http://nuclear.gov/pdfFiles/MMRTG.pdf>.
8. "Ningbo Yingda Lithium Ion Battery Technology Industrial Co., Ltd." 48V
150Ah UPS Li Ion LiMn2O4 Battery,View 48v Battery,YINGDA Product
Details from on Alibaba.com. N.p., n.d. Web. 07 Nov. 2012.
<http://yingdalithium.en.alibaba.com/product/487232050-
212674626/48V_150Ah_UPS_Li_Ion_LiMn2O4_Battery.html>.
9. Narayan, S. R., and Thomas I. Valdez. "High-Energy Portable Fuel Cell
Power Sources." N.p., Winter 2008. Web. 6 Nov. 2012.
<http://www.electrochem.org/dl/interface/wtr/wtr08/wtr08_p40-45.pdf>.
10. "High Energy Density Fuel Cell Systems." Palo Alto Research Center, Inc.,
n.d. Web. 6 Nov. 2012.
<http://www.parc.com/content/attachments/fuelcells_arpa-e_parc.pdf>.
Team B3 55 Power, Propulsion and Thermal Design
ENAE 483
References Cont.
11.Harris, Daniel K. "Chapter 7: Thermal Considerations of Lunar Based
Systems." Chapter 7. ESMD Course Material: Fundamentals of Lunar and
Systems Engineering for Senior Project Teams, with Application to a Lunar
Excavator, n.d. Web. 07 Nov. 2012.
<http://education.ksc.nasa.gov/esmdspacegrant/LunarRegolithExcavatorC
ourse/Chapter7.htm>.
12.Gilmore, David G. Spacecraft Thermal Control Handbook. El Segundo,
CA: Aerospace, 2002. Print.
Team B3 56 Power, Propulsion and Thermal Design
ENAE 483
