वाल्वलेस इसके अंग्रेजी अर्थ का उदाहरण

All these are descended from the old United States Army G major "straight" (valveless) standard bugles adopted in 1892 Army-wide.

Norway international footballers A valveless pulsejet (or pulse jet) is the simplest known jet propulsion device.

They have all the advantages (and most of the disadvantages) of conventional valved pulsejets, but without the reed valves that need frequent replacement - a valveless pulsejet can operate for its entire useful life with practically zero maintenance.

The valveless pulsejet is, mechanically speaking, the simplest form of pulsejet, and is, in fact, the simplest known air-breathing propulsion device that can operate "statically", i.

Some basic differences between valved and valveless pulsejets are:.

In valveless engines, the intake section has an important role to play throughout the entire pulsejet cycle.

The valveless pulsejet is not really valveless "mdash; it just uses the mass of air in the intake tube as its valve, in place of a mechanical valve.

In all known successful valveless pulsejet designs, the intake air mass is a small fraction of the tailpipe air mass (due to the smaller dimensions of the intake duct).

In the valveless engine, there will actually be two arrivals of rarefaction waves "mdash; first, from the intake and then from the tailpipe.

In typical valveless designs, the wave that comes back from the intake will be relatively weak.

While it is theoretically possible to have such an engine without a distinct "combustion chamber" larger than the tailpipe diameter, all successful valveless engines designed so far have a widened chamber of some sort, roughly similar to that found in typical valved engine designs.

Successful valveless pulsejets have been built from a few centimeters in length to huge sizes, though the largest and smallest have not been used for propulsion.