Harrington Rocket Fuel Pump space 2004

Reduce Launch Vehicle Costs while Maintaining Safety and Reliability: 

Reduce Launch Vehicle Costs while Maintaining Safety and Reliability To reduce costs, start with the most expensive component: the pump. The turbopump and its integration are the most expensive and difficult to engineer parts of a liquid fueled launch vehicle. Turbopump 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. Launch Vehicle and Spacecraft System Design Using the Pistonless Pump Steve Harrington, Ph.D. 9-28-04 AIAA Space 2004 Photo: Static test of SDSU rocket June 24, 2004

Outline: 

Outline Pump concept: How does it work? Pump advantages for launch vehicles and spacecraft compared to the state of the art. Pump test results. Comparison of pistonless pump launch vehicle system with turbopump system.

Slide3: 

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. Overlap allows for steady flow and pressure More info at: www.rocketfuelpump.com

Slide4: 

Pump Animation Pump starts with both chambers full, in thermal equilibrium. One chamber is pressurized, and fuel is delivered until level gets low in that chamber. The pressure is applied to both chambers, and fuel is delivered briefly from both chambers. Then the nearly empty chamber is vented and refilled and the cycle repeats.

Advantages : 

Advantages Inexpensive materials and processes. No precision parts. Inherent reliability and sustainability. 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

Affordable and Reliable: Dual Pistonless Pump: 

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

Expensive and Difficult to Design and Build and Integrate: Turbopumps: 

Expensive and Difficult to Design and Build and Integrate: Turbopumps Failure mode: Explosion Complex system Fluid Dynamics of inducer/rotor/turbine Bearings and Materials Seals Cavitation/NPSH Heat transfer Thermal shock Rotor dynamics Startup & Shut down Integration and tuning

Pistonless Pump Development Plan : 

Pistonless Pump Development Plan Needs to be flown. Vernier powered rocket with pumps is being designed now. Will be built and flown with SDSU student group. 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. Pistonless pump does not add energy to pumped fluid due to low velocities.

Pump Performance:: 

Pump Performance: 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

Pump and Valve Assembly: 

Pump and Valve Assembly

Pump and Tank Assembly: 

Pump and Tank Assembly

Pistonless Pump Rocket Design: 

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.) Showing Relative Sizes of Tanks, Pumps and Pressurant

Slide13: 

How to compare rocket system designs? You must include the system, because there are weight and performance tradeoffs for every element. For first order rocket design, must consider the mass of each component: Engine (scales with thrust) Turbopump engines include pump mass Pump (scales with flow and pressure or thrust) Pistonless pump is assumed to be in tank. Pump driver (scales with flow and pressure) Propellant for gas generator or Helium+tanks Tanks (scales with propellant mass) Also scales with pressure for pressure fed Structure, Avionics, etc. (scales with payload)

Slide14: 

Comparison: Gross Liftoff weight of LOX/RP1 first stage with other designs at optimum pressure Typical component masses based on Saturn V first stage (V=3500 m/s) and are scaled by pressure and fuel mass. Pressure fed tank, pistonless pump and pressurant mass scales with propellant mass times pressure. Pistonless 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 leave only .2% Gas generator turbopump systems use 2.5% of propellant in gas generator so Isp is 97.5% of ideal at 900 psi Pc Liquid helium system uses .9% of propellant weight for pressurant, constantly discarded.

Slide17: 

Ratio of GLOW to Payload for Liquid Powered Pistonless Pump Stage LOX/RP-1 at pressures of 1000-2600 psi ( 7-22 MPa). 4.6@3500 m/s

Slide18: 

Ratio of GLOW to Payload for Gas Generator Turbopump stage LOX/RP-1 at pressures of 900-1500 psi ( 6-10 MPa). 4.85@3500 m/s

Slide19: 

Ratio of GLOW to Payload for Gas Powered Pistonless Pump Stage LOX/RP-1 at pressures of 700-1300 psi ( 5-9 MPa). 5.1 @3500 m/s

Slide20: 

Ratio of GLOW to Payload for Pressure Fed Stage LOX/RP-1 at pressures of 300-700 psi ( 2-5 MPa). 6.2@3500 m/s

Slide22: 

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

Conclusions/ Future Plans: 

Conclusions/ Future Plans Pump based system weight and cost are low and it works as designed. Replace turbopumps for light to medium lift vehicles at reduced cost Next steps: Static test and fly pump in rocket with mass ratio of 3-4. Build, test and optimize liquid helium pump Team up with vehicle and engine builders to make launch vehicle and space propulsion systems more safe, reliable and affordable. NASA Fastrac TRW Low Cost Pintle Engine SpaceX Merlin Microcosm Scorpius