science

Vortex ring gun

Vortex ring gun is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Vortex ring gun rather than just read about it. In short: The vortex ring gun is an experimental non-lethal weapon for crowd control that uses high-energy vortex rings 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.

Key takeaways

Vortex ring gun belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Vortex ring gun to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Vortex ring gun from memory before moving on to harder problems.

Reference excerpt

The vortex ring gun is an experimental non-lethal weapon for crowd control that uses high-energy vortex rings 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 is fired into a gun barrel that has a diverging nozzle 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 vortex ring 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 as a means to deliver chemical weapons. 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 Air Ray Gun.

The 1998 U.S. Army project The United States Army Research Laboratory 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, with support by ARDEC. Contributors to the study included individuals from the US Army's Aberdeen Proving Grounds, Adaptive Research Incorporated, Berkeley Research Associates, EWS Limited, Johns Hopkins University, Pennsylvania State University, 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 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. The foremost reliability issue with this project was turbulence caused by the high-energy propellant burning outside the barrel.

See also Bamboo cannon Boga (noisemaker) Bubble ring Potato cannon Air vortex cannon Big-Bang Cannon

References

External links Overview of the vortex ring gun program Live rifle fire and computer modeling of the muzzle blast vortex ring Engineering design of the prototype vortex ring gun

Illustrations

Worked examples

Example 1 — a first encounter with Vortex ring gun

Start with the simplest possible case. Write down what Vortex ring gun claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Vortex ring gun before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Vortex ring gun ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Vortex ring gun

In research: Vortex ring gun appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Vortex ring gun in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Vortex ring gun is common in secondary-school and first-year university syllabi. It links to neighbouring topics Non-lethal firearms, Vortices, so understanding it makes those chapters shorter.
In everyday life: Look for Vortex ring gun outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Vortex ring gun in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Vortex ring gun means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Vortex ring gun out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Vortex ring gun in simple terms?

Why does Vortex ring gun matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Vortex ring gun?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Vortex ring gun.