propulsion systems design€¦ · from g. p. sutton, rocket propulsion elements (5th ed.) john...
TRANSCRIPT
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Propulsion Systems Design
• Lecture #23 - November 12, 2019 • Rocket engine basics • Survey of the technologies • Propellant feed systems • Propulsion systems design
1
© 2019 David L. Akin - All rights reserved http://spacecraft.ssl.umd.edu
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Team Project #2 - Due 12/5/19• Based on ENAE 484 teams • Requirements document draft
– Level 1 requirements – Start of flow-down to levels 2, 3, 4…
• Concept of operations • Prioritized list of trade studies • Analysis results to date on top-priority studies • Conceptual/“strawman” design (CAD, mass est.) • Plans for Spring term (notional schedule)
2
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Propulsion Taxonomy
Ion
MPD
Non-ThermalThermal
Non-ChemicalChemical
Monopropellants Bipropellants
Pressure-Fed Pump-Fed
LiquidsSolids Hybrids Air-Breathing
Solar Sail
Laser Sail
Microwave Sail
MagnetoPlasma
ED Tether
Nuclear
Electrical
Solar
Beamed
Cold Gas
Mass Expulsion Non-Mass Expulsion
3
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Thermal Rocket Exhaust Velocity
• Exhaust velocity is
where
4
ve =2γ
γ − 1ℜTo
M1 − ( pe
po )γ − 1
γ
M ≡ average molecular weight of exhaust
ℜ ≡ universal gas constant = 8314.3JoulesmoleoK
γ ≡ ratio of specific heats ≈ 1.2
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Ideal Thermal Rocket Exhaust Velocity
• Ideal exhaust velocity is
• This corresponds to an ideally expanded nozzle • All thermal energy converted to kinetic energy of
exhaust • Only a function of temperature and molecular
weight!
5
ve,ideal =2γ
γ − 1ℜTo
M
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Thermal Rocket Performance
• Thrust is
• Effective exhaust velocity
• Expansion ratio
6
T = ·mve + (pe − pamb)Ae
T = ·mc ⟹ c = ve + (pe − pamb)Ae·m (Isp =
cgo )
At
Ae= ( γ + 1
2 )1
γ − 1
( pe
po )1γ γ + 1
γ − 11 − ( pe
po )γ − 1
γ
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
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
• Isp,vacuum=455 sec --> Isp,sl=397 sec
7
ve1
ve2=
pγ − 1
γo − p
γ − 1γ
e1
pγ − 1
γo − p
γ − 1γ
e2
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Solid Rocket Motor
8
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Solid Propellant Combustion Characteristics
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
9
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Solid Grain Configurations
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
10
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Short-Grain Solid Configurations
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
11
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Advanced Grain Configurations
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
12
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Liquid Rocket Engine
13
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Liquid Propellant Feed Systems
14
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Space Shuttle OMS Engine
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 2001
15
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Turbopump Fed Liquid Rocket Engine
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
16
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Sample Pump-fed Engine Cycles
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
17
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Gas Generator Engine Schematic
18
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
SpaceX Merlin 1D Engines
19
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Falcon 9 Octoweb Engine Mount
20
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Staged-Combustion Engine Schematic
21
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
RD-180 Engine(s) (Atlas V)
22
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
SSME Powerhead Configuration
23
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
SSME Engine Cycle
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
24
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Liquid Rocket Engine Cutaway
25
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 2001
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
H-1 Engine Injector Plate
26
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Injector Concepts
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
27
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
TR-201 Engine (LM Descent/Delta)
28
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Solid Rocket Nozzle (Heat-Sink)
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
29
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Ablative Nozzle Schematic
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
30
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Active Chamber Cooling Schematic
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
31
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Boundary Layer Cooling Approaches
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
32
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Hybrid Rocket Schematic
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
33
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Hybrid Rocket Combustion
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
34
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Thrust Vector Control Approaches
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
35
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
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
36
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Single-Axis Equations of Motion
37
⌧ = I ✓
⌧
It = ✓ + C1
at t = 0, ✓ = ✓o
=) ⌧
It = ✓ � ✓
o
at t = 0, ✓ = ✓o
=) 1
2
⌧
It2 + ✓
o
t = ✓ � ✓o
1
2
⌧
It2 + ✓
o
t = ✓ + C2
1
2
⇣✓2 � ✓
o
2⌘=
⌧
I(✓ � ✓
o
)
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Attitude Trajectories in the Phase Plane
38
!3.00%
!2.00%
!1.00%
0.00%
1.00%
2.00%
3.00%
!20.00% !10.00% 0.00% 10.00% 20.00% 30.00% 40.00%
tau/I=0%
!0.001%
!0.002%
!0.003%
!0.004%
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Gemini Entry Reaction Control System
39
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Apollo Reaction Control System
40
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
RCS Quad
41
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Apollo CSM RCS Assembly
42
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Lunar Module Reaction Control System
43
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
LM RCS Quad
44
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Viking Aeroshell RCS Thruster
45
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Viking RCS Thruster Schematic
46
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Space Shuttle Primary RCS Engine
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
47
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Monopropellant Engine Design
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
48
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Cold Gas Thruster Exhaust Velocity
49
Ve
=
vuut 2�
� � 1
<T0
M
"1�
✓pe
po
◆ ��1�
#
Ve =
vuut 2(1.4)
1.4� 1
8314.3(300)
28
"1�
✓2
300
◆ 1.4�11.4
#= 689
m
sec
Assume nitrogen gas thrusters
M = 28
T0 = 300 K
p0 = 300 psi
pe = 2 psi
� = 1.4< = 8314.3
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Cold-gas Propellant Performance
From G. P. Sutton, Rocket Propulsion Elements (5th ed.) John Wiley and Sons, 1986
50
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Total Impulse
• Total impulse It is the total thrust-time product for the propulsion system, with units <N-sec>
• To assess cold-gas systems, we can examine total impulse per unit volume of propellant storage
51
It = Tt = mvet
t =⇢V
m
It = ⇢V ve
ItV
= ⇢ve
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Performance of Cold-Gas Systems
52
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Self-Pressurizing Propellants (CO2)
53
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Self-Pressurizing Propellants (N2O)
54
Density1300 kg/m3
Density625 kg/m3
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
N2O Performance Augmentation
• Nominal cold-gas exhaust velocity ~600 m/sec • N2O dissociates in the presence of a heated
catalystengine temperature ~1300°C exhaust velocity ~1800 m/sec
• NOFB (Nitrous Oxide Fuel Blend) - store premixed N2O/hydrocarbon mixtureexhaust velocity >3000 m/sec
55
2N2O �! 2N2 +O2
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Pressurization System Analysis
Pg0, Vg
PL, VL
Pgf, Vg
PL, VL
Adiabatic Expansion of Pressurizing Gas
Initial Final
€
pg,0Vgγ = pg, fVg
γ + plVlγ
Known quantities:
Pg,0=Initial gas pressure
Pg,f=Final gas pressure
PL=Operating pressure of propellant tank(s)
VL=Volume of propellant tank(s)
Solve for gas volume Vg
56
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Boost Module Propellant Tanks
• Gross mass 23,000 kg – Inert mass 2300 kg – Propellant mass 20,700 kg – Mixture ratio N2O4/A50 = 1.8 (by mass)
• N2O4 tank – Mass = 13,310 kg – Density = 1450 kg/m3
– Volume = 9.177 m3 --> rsphere=1.299 m • Aerozine 50 tank
– Mass = 7390 kg – Density = 900 kg/m3
– Volume = 8.214 m3 --> rsphere=1.252 m
57
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Boost Module Main Propulsion
• Total propellant volume VL = 17.39 m3
• Assume engine pressure p0 = 250 psi • Tank pressure pL = 1.25*p0 = 312 psi • Final GHe pressure pg,f = 75 psi + pL = 388 psi • Initial GHe pressure pg,0 = 4500 psi • Conversion factor 1 psi = 6892 Pa • Ratio of specific heats for He = 1.67
• Vg = 3.713 m3 • Ideal gas: T=300°K --> ρ=49.7 kg/m3 (4500 psi = 31.04 MPa) MHe=185.1 kg
€
4500 psi( )Vg1.67 = 388 psi( )Vg
1.67 + 312 psi( ) 17.39 m 3( )1.67
€
ρHe =pg,0M ℜT0
58
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Autogenous Pressurization
• Use gaseous propellants to pressurize tanks with liquid propellants
• Heat exchanger to gasify and warm propellants, then route back into ullage volume
• Eliminates need for pressurized gases for ullage and high-pressure storage bottles (e.g., Falcon 9 failures)
• Issue: start-up transient
59
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Nuclear Thermal Rockets
• Heat propellants by passing through nuclear reactor
• Isp limited by temperature limits on reactor elements (~900 sec for H2 propellant)
• Mass impacts of reactor, shielding
• High thrust system
60
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Electrostatic Ion Thruster
61
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Hall-Effect Thruster
62
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Ion Engine Schematic
63
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Ion Engines Existing/In Development
• NSTAR (NASA Solar Technology Application Readiness) – DS1 and Dawn – 30 cm, 2.3 kW, 92 mN, 3120 sec
• NEXT (NASA Evolutionary Xenon Thruster) – Available 2019 – 6.9 kW power, 236 mN thrust, Isp 4190 sec
• HiPEP (High Power Electric Propulsion) – TRL 3 – 670 mN, 39.3 kW, 7 mg/sec prop, Isp 9620 sec
64
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Variable Specific Impulse Magnetoplasma
65
By Source (WP:NFCC#4), Fair use, https://en.wikipedia.org/w/index.php?curid=35831241
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
VASIMR Engine Concept
66
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
VASIMR Operating Specifications
• Optimum operating point – Isp 5000 sec – Thrust 5.7 N – Power 200 kW
• Can be derated for higher thrust at lower Isp • Compare to ion engines at equivalent power
– 87 NSTAR thrusters: 8 N, 3120 sec Isp – 29 NEXT thrusters: 6.8 N, 4190 sec Isp – 5 HiPEP thrusters: 3.4 N, 9620 sec Isp
67
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Solar Sails
• Sunlight reflecting off sail produces momentum transfer
• At 1 AU, P=1394 W/m2
• c=3x108 m/sec • T=9x10-6 N/m2
€
T = 2 ˙ m V = 2 ˙ m c
€
E = mc2 ⇒ m =Ec 2 ⇒ ˙ m = E
t1c2 =
Pc 2
68
Propulsion Systems Design ENAE 483/788D - Principles of Space Systems Design
U N I V E R S I T Y O FMARYLAND
Propulsion TaxonomyMass Expulsion Non-Mass Expulsion
Non-ThermalThermal
Non-ChemicalChemical Solar Sail
Laser Sail
Microwave Sail
MagnetoPlasma
Monopropellants Bipropellants
LiquidsSolids Hybrids
Pressure-Fed Pump-Fed
Ion
MPDNuclear
Electrical
Solar
Air-Breathing ED Tether
Beamed
Cold Gas
69