1. Lesson 12: Hybrid Propulsion System Design
Dr. Andrew Ketsdever

2. Hybrid Ballistics

3. Hybrid Ballistics
Fuel is vaporized as a result of heat transferred from the flame zone to the fuel grain
Convection
Radiation
Vaporized fuel and oxidizer mix in the port
The flame is established at a location within the boundary layer determined by stoichiometric conditions

4. Hybrid Ballistics

6. Hybrid Propulsion Design Process
Start by establishing mission requirements
Preliminary Design
Make Preliminary Decisions
Propellants
Number of ports
Port configuration
Estimate Performance
Simulations – Codes
Design meets requirements?
Size/Configure Components

7. Preliminary Design Decisions
Choose Propellants
Usual combination
Solid Fuel / Liquid Oxidizer
Choose a design O/F
O/F varies
Decreases down port
Increases with time
Evaluate Thermochemistry
Code / Appendix B (SPAD)
g, mw, To, c*

8. Example: O/F Variation with Time
HTPB / LOx
Rp, i = 7 cm
Gox = 350 kg/m2 sec
Po = 3.45 MPa
Time (s) 10 30 50
O/F
1.72
2.01
2.33
2.53
Isp (s)
249.4
254.7
254.3
252.1

9. Example: Continued O/F = 2.13 for maximum Isp (255.1 sec)
In example, O/F ranges from 1.72 to 2.53 over the 50 sec burn
20% variation from ideal O/F
Average Isp = sec (0.5% less than max)

10. Preliminary Design Determine Pressure Levels
Combustion chamber pressure determined by performance characteristics
Thrust, Isp
Two pressure systems
Pressurant-fed
Pump-fed
Design of these systems similar to liquid propulsion system designs
DPlosses must be considered
Feedlines, dynamic pressure, injectors

11. Preliminary Design Determine the Initial Propellant Flow
Thrust requirement
O/F ratio must be selected
Isp estimated (thermochemistry code)
Mass flow rates can be calculated
Oxidizer
Fuel

12. Preliminary Design Configure the Combustion Ports Volumetric Loading
Number
Configuration
Depends on thrust (mass flow, burn area) required
Optimize volumetric loading
Reduce left over (unburnt) propellant
Volumetric Loading

14. Motor Parameters
MS Word File…

15. GIRD-09
Manufacturer: Korolev. Apogee: 5 km. Liftoff Thrust: 30 kgf. Total Mass: 18 kg. Core Diameter: 0.17 m. Total Length: 2.46 m. Span: 0.63 m.
The first rocket successfully launched by the Soviet GIRD organization was a hybrid (1933).
Used a liquid oxygen to burn gelled petroleum in large casing.
1933 Aug 17 - Russian hybrid propellant rocket, designed by M. K. Tikhonravov, successfully flown. Reached 400 m; design altitude of 5000 m not reached due to loss of pressure integrity of the motor flank.

16. Dolphin
Manufacturer: AMROC. Launches: 1. Failures: 1. Success Rate: pct. First Launch Date: 3 August Last Launch Date: 3 August Launch data is: complete. Apogee: 2 km. Liftoff Thrust: kN. Total Mass: 7,500 kg. Core Diameter: 1.07 m. Total Length: m.
Started with Private Funds – After the failed first launch due to TVC the venture folded.
A sea launch arrangement was used for lift-off - the booster floated in the ocean separately from the launch support ship.

17. HYSR
Manufacturer: Lockheed Martin. Launches: 1. First Launch Date: 18 December Last Launch Date: 18 December Apogee: 70 km. Liftoff Thrust: 27,000 kgf. Core Diameter: 0.20 m. Total Length: 6.00 m.
In 1999 Lockheed Martin signed a Space Act Agreement with NASA Marshall Space Flight Center to develop, test and launch the hybrid sounding rocket.
The program goal was to develop a single-stage hybrid propulsion system capable of replacing existing two- and three-stage sounding rockets.
Hybrid propulsion offered significant advantages over solid fuel propellants in that hybrids were non-explosive, could be throttled, and were low cost and environmentally benign.

18. SpaceShipOne
Binnie Date: 4 October :49 GMT. . Landing Date: 4 October Flight Time: days. Flight Up: SpaceShipOne Flight 17P. Flight Back: SpaceShipOne Flight 17P. Program: X-Prize. Firsts: Suborbital altitude record for a manned spaceplane.
Sixth powered flight of Burt Rutan's SpaceShipOne and winner of the $10 million X-Prize by becoming the second flight over 100 km within a week.
Objectives of the flight were to win the Ansari X-Prize and break the rocketplane altitude record set by the X-15 in The Tier One (White Knight/SpaceShipOne) composite aircraft took off at 06:49 PST. Drop of the rockeplane was made exactly one hour later at 14.4 km altitude. Pilot Brian Binnie fired the hybrid rocket motor, which burned for 83 seconds. The engine cut off with SpaceShipOne at Mach 3.09 (3524 kph) at 65 km altitude. From there it coasted to 112 km altitude. The spacecraft reached Mach 3.25 G's during re-entry and a peak deceleration of 5.4 G's at 32 km altitude.
2004 Oct 4 - SpaceShipOne Flight 17P - X-Prize Flight 2 Flight Crew: Binnie, Spacecraft: SpaceShipOne. Nation: USA. Launch Site: Mojave . Launch Vehicle: Tier One. Duration: days. Apogee: 112 km.

19. SpaceDev Hybrid
Designer: SpaceDev. Developed in: Application: Rocketplane boost. Gross Mass: 2,700 kg. Empty Mass: 300 kg. Propellants: N2O/Solid Thrust(vac): 7,500 kgf. Isp: 250 sec. Burn time: 80 sec. Chambers: 1. Chamber Pressure: bar. Country: USA. Status: Hardware.

20. Falcon: Recent Test
2/4/2005 - EDWARDS AIR FORCE BASE, Calif. (AFPN) -- A large hybrid rocket motor was successfully fired on its test stand.
The test took place on a Air Force Research Laboratory test stand overlooking Edwards’ dry lake bed and surrounding Mojave Desert. The test was part of the Air Force small launch vehicle office’s Falcon program.
The program is a 36-month long effort to develop and demonstrate an affordable and responsive space lift launcher capable of placing a small, 1,000-pound satellite into a circular orbit of 100 nautical miles.
The research site encompasses 65 square miles of Edwards AFB. Its unique research and development facilities provide state-of-the-art capabilities for researchers who provide the nation with the latest rocket propulsion technology possible.