Lesson 12: Hybrid Propulsion System Design

Dr. Andrew Ketsdever

Hybrid Ballistics

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

Hybrid Ballistics

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

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)

• , mw, To, c*

Example: O/F Variation with Time

• HTPB / LOx

• Rp, i = 7 cm

• Gox = 350 kg/m2 sec

• Po = 3.45 MPa

Time (s) 0 10 30 50

O/F 1.72 2.01 2.33 2.53

Isp (s) 249.4 254.7 254.3 252.1

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 = 253.9 sec (0.5% less than max)

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

– Plosses must be considered• Feedlines, dynamic pressure, injectors

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

Preliminary Design

• Configure the Combustion Ports– Number– Configuration– Depends on thrust (mass

flow, burn area) required– Optimize volumetric

loading– Reduce left over (unburnt)

propellant

• Volumetric Loading

VolumeTotalGrain

olumeSolidFuelVV

Motor Parameters

• MS Word File…

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.

Dolphin• Manufacturer: AMROC. Launches: 1.

Failures: 1. Success Rate: 0.000 pct. First Launch Date: 3 August 1984. Last Launch Date: 3 August 1984. Launch data is: complete. Apogee: 2 km. Liftoff Thrust: 155.00 kN. Total Mass: 7,500 kg. Core Diameter: 1.07 m. Total Length: 15.50 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.

HYSR

• Manufacturer: Lockheed Martin. Launches: 1. First Launch Date: 18 December 2002. Last Launch Date: 18 December 2002. 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.

SpaceShipOne• Binnie Date: 4 October 2004 14:49 GMT. . Landing Date: 4 October

2004. Flight Time: 0.017 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 1963. 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: 0.017 days. Apogee: 112 km.

SpaceDev Hybrid

• Designer: SpaceDev. Developed in: 2001-2004. 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: 24.00 bar. Country: USA. Status: Hardware.

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.