Propulsion Systems Design • Lecture #18 - October 29, 2020 • Rocket engine basics • Survey of the technologies • Propellant feed systems • Propulsion systems design
© 2020 David L. Akin - All rights reserved http://spacecraft.ssl.umd.edu U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 1 Grading Rubric for Team Project #2 • Overall design (interior/exterior views, dimensioned 3- view, functionality in mission application) – 10 pts • Habitability design (crew accommodations, usage allocation, galley, waste management, windows) - 10 pts • Life support systems design (trade studies, installation in CAD design, provision of resupply) – 10 pts • Accommodation of visiting vehicles (docking ports, hatches, cargo interfaces) – 10 pts • EVA accommodations (airlock(s)/suitports, suit donning/doffing/recharging stations, dust remediation) – 10 pts U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 2 Grading Rubric for Term Project #2 • Logistics management (volume allocation, crew access, ability to restock) – 10 pts • Concept of operations (How will the habitat be used? “day in the life”… how well does it fit the mission?) – 10 pts • Presentation quality (“telling the story”, engaging the reader, adhering to principles from class) - 10 pts • CAD quality (details, fidelity, complexity) - 20 pts • “Above and beyond” (extra effort outside of nominal expectations) - 10 pts extra credit
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 3 Propulsion Taxonomy
Mass Expulsion Non-Mass Expulsion
Thermal Non-Thermal
Ion Chemical Non-Chemical Solar Sail
MPD Laser Sail Nuclear Monopropellants Bipropellants Beamed Electrical Microwave Sail Cold Gas Solar MagnetoPlasma
Solids Hybrids Liquids Air-Breathing ED Tether
Pressure-Fed Pump-Fed
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 4 Thermal Rocket Exhaust Velocity • Exhaust velocity is
γ − 1 γ 2γ ℜTo pe ve = 1 − γ − 1 M¯ ( po ) where M¯ ≡ average molecular weight of exhaust Joules ℜ ≡ universal gas constant = 8314.3 moleoK γ ≡ ratio of specific heats ≈ 1.2
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 5 Ideal Thermal Rocket Exhaust Velocity • Ideal exhaust velocity is
2γ ℜTo ve,ideal = γ − 1 M¯ • This corresponds to an ideally expanded nozzle • All thermal energy converted to kinetic energy of exhaust • Only a function of temperature and molecular weight!
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 6 Thermal Rocket Performance • Thrust is · T = mve + (pe − pamb)Ae • Effective exhaust velocity · Ae c T = mc ⟹ c = ve + (pe − pamb) Isp = m· ( go ) • Expansion ratio
1 γ − 1 1 γ γ A γ + 1 γ − 1 p γ + 1 p t = e 1 − e Ae ( 2 ) ( po ) γ − 1 ( po )
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 7 Nozzle Design
• Pressure ratio p0/pe=100 (1470 psi-->14.7 psi) Ae/At=11.9
• Pressure ratio p0/pe=1000 (1470 psi-->1.47 psi) Ae/At=71.6
• Difference between sea level and vacuum Ve γ − 1 γ − 1 γ γ ve1 po − pe1 = γ − 1 γ − 1 ve2 γ γ po − pe2 • Isp,vacuum=455 sec --> Isp,sl=397 sec
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 8 Solid Rocket Motor
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986 U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 9 Solid Propellant Combustion Characteristics
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986 U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 10 Solid Grain Configurations
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986 U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 11 Short-Grain Solid Configurations
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 12 Advanced Grain Configurations
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 13 Liquid Rocket Engine
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 14 Liquid Propellant Feed Systems
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 15 Space Shuttle OMS Engine
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 2001 U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 16 Turbopump Fed Liquid Rocket Engine
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986 U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 17 Sample Pump-fed Engine Cycles
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986 U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 18 Gas Generator Engine Schematic
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 19 SpaceX Merlin 1D Engines
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 20 Falcon 9 Octoweb Engine Mount
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 21 Staged-Combustion Engine Schematic
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 22 RD-180 Engine(s) (Atlas V)
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 23 SSME Powerhead Configuration
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 24 SSME Engine Cycle
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986 U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 25 Liquid Rocket Engine Cutaway
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 2001 U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 26 H-1 Engine Injector Plate
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 27 Injector Concepts
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986 U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 28 TR-201 Engine (LM Descent/Delta)
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 29 Solid Rocket Nozzle (Heat-Sink)
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986 U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 30 Ablative Nozzle Schematic
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 31 Active Chamber Cooling Schematic
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986 U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 32 Boundary Layer Cooling Approaches
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986 U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 33 Hybrid Rocket Schematic
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 34 Hybrid Rocket Combustion
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986 U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 35 Thrust Vector Control Approaches
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986 U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 36 Reaction Control Systems • Thruster control of vehicle attitude and translation • “Bang-bang” control algorithms • Design goals: – Minimize coupling (pure forces for translation; pure moments for rotation)except for pure entry vehicles – Minimize duty cycle (use propellant as sparingly as possible) – Meet requirements for maximum rotational and linear accelerations
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 37 Single-Axis Equations of Motion ⌧ = I✓¨ ⌧ t = ✓˙ + C I 1 ⌧ at t = 0, ✓˙ = ✓˙ = t = ✓˙ ✓˙ o ) I o 1 ⌧ t2 + ✓˙ t = ✓ + C 2 I o 2 1 ⌧ at t = 0, ✓ = ✓ = t2 + ✓˙ t = ✓ ✓ o ) 2 I o o 1 2 ⌧ ✓˙2 ✓˙ = (✓ ✓ ) 2 o I o U N I V E R S I T Y O⇣ F ⌘ Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 38 Attitude Trajectories in the Phase Plane
3.00%
2.00%
1.00%
0.00% !20.00% !10.00% 0.00% 10.00% 20.00% 30.00% 40.00%
!1.00% tau/I=0% !0.001% !0.002% !2.00% !0.003% !0.004%
!3.00% U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 39 Gemini Entry Reaction Control System
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 40 Apollo Reaction Control System Thrusters
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 41 RCS Quad
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 42 Apollo CSM RCS Assembly
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 43 Lunar Module Reaction Control System
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 44 LM RCS Quad
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 45 Viking Aeroshell RCS Thruster
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 46 Viking RCS Thruster Schematic
U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 47 Space Shuttle Primary RCS Engine
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986 U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 48 Monopropellant Engine Design
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986 U N I V E R S I T Y O F Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design MARYLAND 49 Cold Gas Thruster Exhaust Velocity Assume nitrogen gas thrusters