A pistonless rocket engine propellant pump that is simpler, less problematic and more reliable than existing turbopump systems is being developed by California, USA-based Flometrics.
The design is claimed to work without the vulnerable bearings or seals used in existing pumps, and does not require a minimum amount of unused fuel to be left in stage tanks.
The company says the pistonless pump requires only commercial off-the-shelf flight-tested components, is scalable, can cope with contaminants, and can be throttled like a turbopump system.
The company's basic design uses the valve-controlled release of helium stored at 414bar (6,000lb/in2) to drive propellant from two secondary tanks into the combustion chamber. A central tank, pressurised to 6.9bar, feeds the propellant into the secondary tanks.
Each secondary tank has three valves: one for allowing the helium in, one for releasing the fuel to the chamber, and one for bringing the fuel in from the central tank. Each secondary tank fills while the other empties and this alternating process gives a constant rate of flow to the combustion chamber from both tanks.
"We are talking to [spaceplane developer Rocketplane] pretty seriously about using it for their system," says Steve Harrington, Flometrics' chief executive. The pump's development has been aided by students from San Diego State University.
ROB COPPINGER/LONDON
Source: Flight International