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Water Pulsejet Research

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Final rept.

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The aim of this research was to obtain a quantitative understanding of the McHugh steam water pulsejet cycle, which in its simplest embodiment, is a thrust-producing engine with no moving parts. The cycle is also adaptable to water pumping, a study of which is currently being funded by ERDA or, indeed, to the pumping of any vaporizable fluid. It has also been used as an agitator, and may find applications as such where a fluid or slurry is too corrosive for conventional mechanically-driven pumps or agitators. The basic theory may also be peripherally helpful in such diverse fields as the chugging of atomic reactors during emergency shut-down and the catastrophic explosions which can result from the dynamic mixing of water with lava or molten metal. Although by no means complete, its believed that the theory presented herein adequately explains the McHugh cycle, and points the way for further performance improvements. Steam water pulsejets are not yet as efficient as conventional steam engines, but there may be applications where the rather extreme mechanical simplicity makes them cost effective. In terms of specific fuel consumption, the best engine tested corresponded to about 0.56 lb of fuel per hour per pound of thrust, assuming an 80 boiler efficiency. This is comparable to a turbojet, but, of course, the pulsejet has a natural advantage in the denser medium. Fuel consumption is about five times that expected of a diesel engine driving a water propeller.

Subject Categories:

  • Fluid Mechanics
  • Thermodynamics
  • Jet and Gas Turbine Engines

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