Surrogate weapon for weapons effects signatures

Abstract

The invention comprises a surrogate weapon for simulating the sound and flash of gunfire having a combustion chamber system in which a primary chamber is an elongated cavity, having a proximal end closed with a head and an open distal end. A combustible mixture is injected via electronically timed hydrocarbon fuel and oxidizer pulses into the combustion chamber near the closed end through an annular injector having a plurality of spaced apart fuel and oxidizer nozzles. The fuel nozzles are axially spaced from the oxidizer nozzles and are closer to the head. Thus the injected fuel/oxidizer charge is stratified with a fuel concentration distribution preferentially being richer at an ignition source near the head. The open distal end of the combustion chamber is in the form of an annular convergent nozzle which also comprises the proximal end of a secondary chamber that is acoustically tuned and provided at its open distal end with an annular muzzle having a cross-sectional shape capable of controlling the fundamental frequency and modifying tuned frequency overtones of the acoustic signature. One embodiment provides the fuel nozzles as a plurality of radial grooves on the proximal side of a generally flat plate transverse to the primary combustion chamber cavity and having an aperture therethrough, the aperture being flush with the inner surface of the combustion chamber cavity, and also providing oxidizer nozzles as a plurality of radial grooves on the distal side of the flat plate.