09-06-2012, 01:49 PM
Pistonless pump
PistonlessPumpforRocket.doc.doc (Size: 320 KB / Downloads: 6)
INTRODUCTION:
NASA have developed a Low cost rocket fuel pump which has
Comparable performance to turbopump at 80-90% lower cost. Perhaps
the most difficult barrier to entry in the liquid rocket business is the
turbo pump. A turbo pump design requires a large engineering effort
and is expensive to mfg. and test. Starting a turbo pump fed rocket
engine is a complex process, requiring a careful of many valves and
subsystems.In fact ,Beal aerospace tried to avoid the issue entirely by
building a huge pressure feed booster. Their booster never flew, but the
engineering behind it was sound and ,if they had a low cost pump at
their disposal ,they might be competing against Boeing. This pump
saves up to 90% of the mass of the tanks as compared to a pressure
fed system. This pump has really proved to be a boon for rockets .
NECESSECITY:
The turbo pumps used in rocket are very heavy,containing many
rotating parts by which there are more frictional losses which
more consumption of fuel there by decreasing the efficiency of
the engine .Also, the maintainanace of such pump is, very
important factor since the rocket has to remain stable in the
space, is difficult and require complex methods for it. If this
pump gets any fault then its repairance requires long time and also
it is avery hectic task.So, there must be such a device which
overcomes all the drawbacks of the turbopump as above. The
pistonless pump is the solution for the problems faced by using
turbopumps. They have only a drawback that they supply fuel
with less pressure as compared to turbopumps.
THE DUAL PISTONLESS PUMP:
NASA has designed,built and tested a simple, light weight pump
(dual pistomless pump) for use in liquid propelled rocket 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.
PISTONLESS PUMP FIGURE:
As shown in the above diagram , two cylinders are there ,
filled with the fuel from the main tank. This main tank is
emptied in these two cylinders, these cylinders are
pressurized by the high pressure tank,as shown.The high
pressure tank pressurizes one cylinder of high pressure,as
shown,as soon as the cylinder is emptied , it is vented,
again it gets filled up from the main tank.The same cycle
reapeats for the second cylinder.the cycle is such that,
fuel is supplied by the cylinder one by one.ie. each
cylinder supplies fuel for each half cycle.As one cylinder
supplies the fuel other has enough time to refill.
