rimfire1.htm Rimfire Engine Project

Rimfire Engine Project


Fundamental Principle

The fundamental principle of what I call the "Rimfire" engine is the use of small ramjet, pulsejet, or pressurejet engines mounted at the blade-tips of a fan or outer rim of a wheel. This is a variation on the ramjet powered helicopters built since World War II and advertised in magazines like "Popular Science."

Below is a graphic representation of how this is implemented on helicopters. Small ramjets are mounted at the ends of the rotor blades. When the blades are spun up to high speed the ramjets begin operating and provide thrust to keep the blades turning. Typical tip speeds for helicopters and turbofan engines is Mach 1, or 1000 fps.

The advantage of this type of helicopter was the much simpler and lighter ramjet engines as opposed to piston or turbine engines. The disadvantages were poor fuel efficiency and very loud noise.

Expounding on the Advantages

If the disadvantages can be overcome there are several areas where such engines can dramatically improve the way we do things. The fundamental principle can be scaled up or down almost without limit.

Associated Notes

Noise Reduction

By mounting the rimfire engine inside a duct most of the noise can be dampened. In this manner they should be no noisier than piston driven engines.

More Later



This Page Last Updated 14 Dec 97