Pistonless Dual Chamber Rocket Fuel Pump

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Pistonless Dual Chamber Rocket Fuel Pump

• Steve Harrington, Ph.D.
• 4-21-04

Responsive Space Conference
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Reduce Launch Vehicle Costs while Maintaining
Safety and Reliability

• The turbopump and its integration are the most
  expensive and difficult to engineer parts of a
  liquid fueled launch vehicle. Pump output
  pressure is coupled to flow. Engine pressure
  depends on ignition. Startup must be managed
  carefully.
• Pressure fed tanks are too heavy
• The Pistonless Pump provides a way to achieve low
  launch vehicle system weight and cost. Design,
  test and Integration are straightforward. Full
  pressure is supplied at all flow rates.

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Outline

• Pump design concept
• Pump advantages
• Latest pump innovations including using the pump
  to pressurize liquid helium pressurant
• Pump test results.
• Comparison of pistonless pump launch vehicle
  system with turpopump system.

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First Generation Design

• Drain the main tank at low pressure into a small
  pump chamber.
• Pressurize the pump chamber and feed to the
  engine.
• Run two in parallel, venting and filling one
  faster than the other is emptied

More info at www.rocketfuelpump.com
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Advantages

• Inexpensive materials and processes.
• No precision parts. Inherent reliability
• Robust system can pass contaminants.
• One design will work with many propellants.
• 100 Throttleable, full pressure from zero to
  full flow.
• Can be run dry. No minimum fuel requirement
• Mass producible and scalable, allows for
  redundant systems.
• Can pump liquid helium for low weight pressurant
  systems
• Failure modes are benign

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Affordable and Reliable Dual Pistonless Pump

• Major components
• Check Valves
• Level Sensors
• Actuated valves
• COTS parts are available
• Flight qualified valves are also available
• Sensors can be made redundant

Pump prototype 4 MPa, 1.2 kg/sec, 7 kg (600
psi,20 GPM
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Expensive and Difficult to Design and Build and
Integrate Turbopumps

• Failure mode Explosion
• Complex system
• Fluid Dynamics of inducer/rotor/stator
• Bearings
• Seals
• Cavitation/NPSH
• Heat transfer
• Thermal shock
• Rotor dynamics
• Startup Shut down
• Integration and tuning

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Pistonless Pump Development Plan

• Needs to be flown. Vernier powered rocket with
  pumps is being designed now.
• Gas powered pump at TRL 4, needs high fidelity
  testing with LN2 to get to TRL 5
• Liquid helium pump at TRL 3, issues are related
  to heat transfer, Lhe is very easily vaporized,
  70 times less heat of vaporization than LOX.
  Pistonless pump does not add energy to pumped
  fluid via viscous dissipation due to low
  velocities.

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Pump Performance

• Pump performance close to target of Pressure
  fluctuations are minimal.
• Pump performs better when running on Helium
• Pump gas usage can be reduced by heating gas.

Pump running on compressed air at room
temperature, pumping water at 450 psi,20 GPM
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Pistonless Pump Rocket Design
25,000 lb GLOW Gas Powered Proposed Rocket
Design. (Dimensions in ft.)
25,000 lb GLOW Liquid Powered Proposed Rocket
Design. (Dimensions in ft.)
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Comparison Gross Liftoff weight of LOX/RP1 first
stage with other designs

• Typical component masses based on Saturn V
• Pressure fed tank, pistonless pump and
  pressurant mass scales with propellant mass and
  pressure. Pump is half the weight of the engine.
• Engine and low pressure tanks scale with
  propellant weight
• Structure is a fixed percentage of payload 15
• Turbopump systems have 1.4 residual propellant,
  Pressure fed and Pistonless systems run at .2
• Gas generator turbopump systems use 2.5 of
  propellant in gas generator, Isp is 97.5 of
  ideal
• Liquid helium system uses .9 of propellant
  weight for pressurant, constantly discarded.

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Ratio of GLOW to Payload for Gas Generator
Turbopump stage LOX/RP-1 at pressures of
900-1500 psi ( 6-10 MPa).
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Ratio of GLOW to Payload for Pressure Fed Stage
LOX/RP-1 at pressures of 300-700 psi ( 2-5 MPa).
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Ratio of GLOW to Payload for Gas Powered
Pistonless Pump Stage LOX/RP-1 at pressures of
700-1300 psi ( 5-9 MPa).
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Ratio of GLOW to Payload for Liquid Powered
Pistonless Pump Stage LOX/RP-1 at pressures of
1000-2600 psi ( 7-22 MPa).
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Aerojet engine performance as a function of
pressure.. The engine tradeoff is normalized for
either constant thrust of constant throat size
Courtesy Aerojet General Corp
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Conclusions/ Future Plans

• Pump based system weight and cost are low and it
  works as designed.
• Next steps
• Static test and fly pump in rocket with mass
  ratio of 4.
• Build, test and optimize liquid helium pump
• Along with latest low cost engine designs, pump
  will make launch systems more safe, reliable and
  affordable.

NASA Fastrac
SpaceX Merlin
TRW Low Cost Pintle Engine
Microcosm Scorpius