Vortex ring gun

  1. Pages with broken file links
  2. Non-lethal firearms
  3. Vortices


File:Vortex Ring Gun Schlierin.jpg
Figure 1. Spark photography image of a vortex ring in flight.
File:Optimum Vortex.jpg
Figure 2. Artist’s view of the Vortex Ring Gun concept for firing vortex rings at the maximum possible velocity and spin.
File:Shock Bottle Vortex.jpg
Figure 3. Artist's view of a degraded vortex ring fired without a nozzle.

The vortex ring gun is an experimental non-lethal weapon under development for crowd control. A blank cartridge is fired into a gun barrel that has a diverging nozzle screwed onto the muzzle.[1] 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 vortex ring (Figure 1) with the potential energy to fly hundreds of feet. [2] [3]

Operation

The nozzle 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.[4] The objective (Figure 2) 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 Blast Shock. Without the nozzle (Figure 3), 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.[5]

Partners

File:MK19-3 Machine Gun.jpg
Figure 4. MK19-3 40mm grenade launch machine gun.

A study commissioned by the United States Marine Corps Joint Non-Lethal Weapons Directorate tasked the United States Army Research Laboratory to determine whether optimized vortex rings could be used for non-lethal crowd control. Overall management authority was assigned to the United States Army Materiel Command, Alexandria VA with support by ARDEC Picatinney, NJ. Contributors to the study included individuals from Sara Corporation, Sonic Development Laboratory, EWS Limited, Berkeley Research Associates, Johns Hopkins University, Pennsylvania State University, Adaptive Research Incorporated, and the United States Army Aberdeen Proving Grounds. [6]

Hardware

File:Vortex Ring Gun Test.jpg
Figure 5. Knock down test of a 60 mph (96 km/hr) vortex ring.

The end product was to be a kit designed to quickly convert an existing lethal weapon in inventory to a non-lethal vortex ring generator capable of human knock-down, marking with a dye, applying a malodorous chemical, or applying an incapacitating chemical. The kit, consisting of a nozzle with chemical reservoirs and belts of blank 40mm cartridges modified to detonate at pressures up to 100,000 psi (690 KN/sqN), was being designed for the Navy MK19-3.[7] The 40mm grenade machine gun was selected because firing at 4-10 shots per second resonates with many body parts and causes a stronger impact effect.[8]

Field Tests

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 knock down did not appear to be feasible at the desired range of 100 feet (30 m), 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. [9][10]

Technology Status

The foremost reliability issue with the 1998 Army initiative to launch high kinetic energy vortex rings using high explosives as propellant was turbulence caused by propellant burning outside the barrel. Launchers by commercial enterprises overcome the problem using less energetic gas propellants. The nozzle design for the Hail cannon[11] reliably fires vortex rings at one third[12] the speed of sound or better. Knockdown of distant individuals seems unlikely even for launches at theoretical maximum speed of sound. The most likely military application may be the transport of chemicals if the higher spin reduces in-flight leakage.Template:Citation required

References

  1. ↑ "Defense Update," Qadima Israel internet magazine overview of the Vortex ring Gun.
  2. ↑ George K. Lucey Jr., Vortex Ring Generator: Mechanical Engineering Design For 100Kpsi Operating Pressures, ARL-TR-2096, United States Army Research Laboratory, Adelphi, MD, January 2000
  3. ↑ https://www.youtube.com/watch?v=GteGbZeKsOI
  4. ↑ Dr. John D. Anderson, Jr., "Modern Compressible Flow With Historical Perspective," Second Edition, 1990 McGraw Hill Inc., NY, NY, pp 182-183, 327-329.
  5. ↑ Daniel L. Clear, et. al., "Computational Fluid Dynamics Application To Gun Muzzle Blast - a Validation Case Study," Technical Report ARCCB-TR-03011, August 2003, US Army Armament Research Development And Engineering Center, Picatinney, NJ, Pages 6-7.
  6. ↑ Lucey, G & Jasper, L., Vortex Ring Generator, United States Army Research Laboratory, Adelphi, MD 1998. NLD III Conference, 25 February 1998, Johns Hopkins Applied Physics Lab., pp 1,41
  7. ↑ George K. Lucey Jr., Vortex Ring Generator: Mechanical Engineering Design For 100Kpsi Operating Pressures, ARL-TR-2096, United States Army Research Laboratory, Adelphi, MD, January 2000.
  8. ↑ Rasmussen, G., Human Body Vibrations Exposure And Its Measurement, Bruel and Kjer Technical Paper, 1982. Abstract 1983, Journal of Acoustical Society of America, 73(6) 2229.
  9. ↑ Videos of prototype Vortex Ring Gun field tests. on YouTube
  10. ↑ Sound track of a vortex ring approaching a target on YouTube
  11. ↑ Video of a very high speed Hail Gun vortex ring on YouTube
  12. ↑ Video of knock down tests on YouTube

External links


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