Pistonless Dual Chamber Rocket Fuel Pump Tell them what you going to tell them etc Steve Harrington, Ph.D. 4-02-03

LOX/Jet-A Pressure Fed Design Working Well What’s Next?… More Altitude!

The Problem is Mass Ratio: How to Make a Lightweight, Inexpensive Rocket with a Large Fuel Capacity. For performance, a rocket must have large, lightweight propellant tanks Pressure fed tanks are heavy and/or expensive and safety margins cost too much in terms of performance. Turbopumps require massive engineering effort and are expensive. The solution is the The Dual Pistonless Pump Simple to design and manufacture and with performance comparable to a turbopump

Outline Discuss basic pump design concept Introduce latest pump innovations List pump advantages over turbopump and pressure fed systems. Present pump test results Derive calculation of pump thrust to weight ratio which show that a LOX/RP-1 pump has a T/W of over 700

First Generation Design: Drain the main tank at low pressure into a small chamber. Pressurize the small chamber and feed to the engine. Run two in parallel, venting and filling one faster than the other is emptied Animate diagram More info at: www. rocketfuelpump.com

Second Generation Design: Main chamber vents and fills quickly through multiple check valves. One main chamber and one auxiliary chamber, less weight than two chambers of equal size Pump fits in tank, simplified plumbing Concentric design maintains balance. Model has been built and tested (patent pending) Animate diagram

Advantages Much lighter than pressure fed system at similar cost. At one to two orders of magnitude lower engineering and manufacturing cost than turbopump. Low weight, comparable to turbopump. Quick startup, shutdown. No fuel used during spool up. Can be run dry. No minimum fuel requirement. Less than 10 moving parts. Inherent reliability. Inexpensive materials and processes. Negligible chance of catastrophic failure. Scalable, allows for redundant systems.

Engineering Cost: Dual Pistonless Pump Check Valves Level Sensors Pressure vessels These parts are available off the shelf Control System (microprocessor or logic circuit) Pump model made from industrial/consumer parts 4 MPa, 1.2 kg/sec, 7 kg

Engineering cost: Turbopumps Fluid Dynamics of rotor/stator Bearings Seals Cavitation Heat transfer Thermal shock Rotor dynamics Startup Shut down

Development Issues Pressure Spikes in output may require accumulator or valve timing adjustment Currently uses slightly more gas than pressure fed system. can use less with pressurant heating. Not invented here. No experience base, must be static tested and flown.

Pump Performance: Pump performance close to target of 1.5 kg/sec at 4 Mpa Pressure spikes have been reduced. Requires more development. Pump chamber vents and pressurizes more quickly when running on Helium Pump needs to be tested with LN2 and Jet-A Animate diagram Pump running on compressed air at room temperature, pumping water.

Pistonless Pump Mass Calculation: Chamber Mass Spherical Chamber Volume and Diameter Combine Equations to get Chamber Mass as a function of flow rate Chamber Thickness in terms of fuel pressure and maximum stress

Pistonless Pump Thrust to weight Ratio Calculation: Thrust for Ideal Expansion Assumptions: Auxiliary chamber is 1/4 the size of main chamber Valves and ullage add 25% to mass Total pump mass is 1.252 or1.56 times main chamber mass 1/(1.56*1.5)=.43 Pump thrust to weight

Typical Pump Thrust/Weight Calculations Assumptions: Add graph showing where weight goes. Rocket Chamber Pressure 4 MPa Pump cycle time 5 seconds. Sea level Specific Impulse from Huang and Huzel , Pump Chambers are 2219 aluminum, 350 MPa design yield strength, 2.8 specific gravity

Conclusions/ Future Plans Pump weight and cost are low and it works as designed. Next steps: Static test and fly pump with Flometric’s rocket technology. Combine with low cost ablative engines and low cost vehicles for low cost access to space. NASA Fastrac Beal BA 810 Time is right for this development. TRW Low Cost Pintle Engine Microcosm Scorpius