The vortex ring gun is an experimental

non-lethal weapon Non-lethal weapons, also called nonlethal weapons, less-lethal weapons, less-than-lethal weapons, non-deadly weapons, compliance weapons, or pain-inducing weapons are weapons intended to be less likely to kill a living target than convention ...

for crowd control that uses high-energy

vortex ring A vortex ring, also called a toroidal vortex, is a torus-shaped vortex in a fluid; that is, a region where the fluid mostly spins around an imaginary axis line that forms a closed loop. The dominant flow in a vortex ring is said to be toroidal, ...

s of gas to knock down people or spray them with marking ink or other chemicals. The concept was explored by the US Army starting in 1998, and by some commercial firms. Knockdown of distant individuals currently seems unlikely even if the rings are launched at theoretical maximum speed. As for the delivery of chemicals, leakage during flight is still a problem. Weapons based on similar principles but different designs and purposes have been described before, typically using acetylene-air or hydrogen–oxygen explosions to create and propel the vortices.

Operation

In a typical concept, a

blank cartridge A blank is a firearm cartridge that, when fired, does not shoot a projectile like a bullet or pellet, but generates a muzzle flash and an explosive sound ( muzzle report) like a normal gunshot would. Firearms may need to be modified to allow a ...

is fired into a gun barrel that has a diverging

nozzle A nozzle is a device designed to control the direction or characteristics of a fluid flow (specially to increase velocity) as it exits (or enters) an enclosed chamber or pipe (material), pipe. A nozzle is often a pipe or tube of varying cross ...

screwed onto the muzzle. In the nozzle, the short pulse of high pressure gas briefly accelerates to a supersonic exit velocity, whereupon a portion of the exhaust transforms from axial flow into a subsonic, high spin

with the potential energy to fly hundreds of feet. The nozzle of a vortex ring gun is designed to both contain the short pulse of accelerating gas until the maximum pressure is lowered to atmospheric and to straighten the exhaust into an axial flow. The objective is to form the vortex ring with the highest possible velocity and spin by colliding a short pulse of a supersonic jet stream against the relatively stagnant air behind the spherically expanding shock wave. Without the nozzle, the high pressure jet stream is reduced to atmospheric by standing shock waves at the muzzle, and the resulting vortex ring is not only formed by a lower velocity jet stream but also degraded by turbulence.

History

Invention

The concept was developed by American aircraft builder Thomas Shelton during

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

as a means to deliver

chemical weapon A chemical weapon (CW) is a specialized munition that uses chemicals formulated to inflict death or harm on humans. According to the Organisation for the Prohibition of Chemical Weapons (OPCW), this can be any chemical compound intended as ...

s. Shelton later developed a large version to deliver a mechanical shock. These were never employed for military purposes, and after the war Shelton developed them into vortex ring toys, specifically the

Flash Gordon Flash Gordon is the protagonist of a space adventure comic strip created and originally drawn by Alex Raymond. First published January 7, 1934, the strip was inspired by, and created to compete with, the already established ''Buck Rogers'' ...

Air Ray Gun.

The 1998 U.S. Army project

The

United States Army Research Laboratory The U.S. Army Combat Capabilities Development Command Army Research Laboratory (DEVCOM ARL) is the foundational research laboratory for the United States Army under the United States Army Futures Command (AFC). DEVCOM ARL conducts intramural an ...

was asked by the Marine Corps Joint Non-Lethal Weapons Directorate to determine whether vortex rings could be used for non-lethal crowd control. Overall management authority for the study was assigned to the

United States Army Materiel Command The U.S. Army Materiel Command (AMC) is the primary provider of materiel to the United States Army. The command's mission includes the management of installations, as well as maintenance and parts distribution. AMC operates depots; arsenals; am ...

, with support by ARDEC. Contributors to the study included individuals from the US Army's

Aberdeen Proving Grounds Aberdeen Proving Ground (APG) is a U.S. Army facility located adjacent to Aberdeen, Harford County, Maryland, United States. More than 7,500 civilians and 5,000 military personnel work at APG. There are 11 major commands among the tenant units, ...

, Adaptive Research Incorporated, Berkeley Research Associates, EWS Limited,

Johns Hopkins University The Johns Hopkins University (often abbreviated as Johns Hopkins, Hopkins, or JHU) is a private university, private research university in Baltimore, Maryland, United States. Founded in 1876 based on the European research institution model, J ...

Pennsylvania State University The Pennsylvania State University (Penn State or PSU) is a Public university, public Commonwealth System of Higher Education, state-related Land-grant university, land-grant research university with campuses and facilities throughout Pennsyl ...

, Sara Corporation, and Sonic Development Laboratory. The end product was to be a kit for quickly converting an existing lethal weapon to a non-lethal vortex ring generator that could knock down an individual or spray him with a dye, malodorous chemical, or incapacitating chemical. The kit, consisting of a nozzle with chemical reservoirs and belts of blank 40 mm cartridges modified to detonate at pressures up to 100,000 psi (690 KN/sqN), was being designed for the Navy MK19-3. The 40 mm grenade machine gun was selected because firing at 4–10 shots per second resonates with many body parts and causes a stronger impact effect. Single-shot field tests performed without optimized nozzles led to the conclusion vortex rings were unsuitable for non-lethal crowd control. This conclusion was reached partly because knockdown did not appear to be feasible at the desired range of , partly because of the excessive spillage onto bystanders under the flight path if used to transport chemicals or dyes, and partly because the flight noise and speed enabled it to be easily avoided at the downrange target. The foremost reliability issue with this project was turbulence caused by the high-energy propellant burning outside the barrel.

References

External links