May 26, 2004
Pistonless Pump offers Performance
Flowmetrics has a design for a pistonless pump that they claim is as good as a gas-genertating turbopump for a first stage liquid fueled rocket. Included is this handy animation that shows how this whole thing works. It appears to be very robust, and very high performance.
Posted by elkaim at May 26, 2004 1:53 PMWe are have designed, built and tested a simple, lightweight pump(dual pistonless pump) for use in liquid propelled rockets where a reliable pump with minimal moving parts is needed. This pump has the potential to reduce the cost and increase the reliability of rocket fuel pumps by a factor of 20 to 100. The pump has been tested with a rocket engine and the pump worked perfectly.
How it works:
Rocket engines require a tremendous amount of fuel at high pressure. Often the pump costs more than the thrust chamber. One way to supply fuel is to use the expensive turbopump mentioned above, another way is to pressurize the entire fuel tank. Pressurizing a large tank requires a heavy, expensive tank. However, suppose instead of pressurizing the entire tank, the main tank is drained into a small pump chamber, which is then pressurized. To achieve steady flow, the pump system consists of two pump chambers such that each one supplies fuel for ½ of each cycle. The pump is powered by pressurized gas which acts directly on the fluid. For each half of the pump system, a chamber is first filled from the main tank under low pressure and at a high flow rate, then the chamber is pressurized, and then the fluid is delivered to the engine at a moderate flow rate under high pressure. The chamber is then vented and the cycle repeats. The system is designed so that the inlet flow rate is higher than the outlet flow rate. This allows time for one chamber to be vented, refilled and pressurized while the other is being emptied. (See Figure 1 below) A bread board pump has been tested and it works great. A high pressure version has been designed and built and is pumping at 20+ gpm and 550+ psi.