Questions tagged [vortex-ring-state]

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, more precisely poloidal.

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Can vortex ring state (VRS) be solved by shaping the blades so that the vortexes they produce are weak enough not to form a vortex ring?

Vortex Ring State is one of the hazardous states a helicopter can find itself into. VRS happens when a helicopter has low airspeed (and usually hovering OGE) and is descending. If the helicpoter is ...
BanzaiFighterbomber's user avatar
2 votes
1 answer

Is there an exact solution for induced velocity during vortex ring state?

In plots such as these, the section between -2 and 0 has no exact solution. As shown in the first image, the other two formulas are known, but not during vortex ring state because, as seen in the ...
Alexander James Hughes's user avatar
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Can a helicopter enter Vortex Ring State In Auto Rotation? [see qualifiers]

If you are in a vertical descent [no wind] with rotor at max RPM Auto, and you abruptly pull full collective, the momentum of the blades will drive air down creating down wash. Now obviously this is ...
wanna-beCanadianPilot's user avatar
9 votes
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Can a VTOL jet such as the Harrier enter a Vortex Ring State?

I'm curious, because they obviously don't have those huge rotors pushing the air away, but they are still getting their upward thrust from somewhere. My gut says, yes, but it is more difficult. Is ...
Bassinator's user avatar
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Why is vortex state impossible in autorotation?

An article at Skybrary states that for a vortex ring state to occur: The aircraft has to be in powered flight. If the engines are not producing power, the aircraft is in autorotation and the upflow ...
TomMcW's user avatar
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What is "settling with power" and how does it differ from vortex ring state?

I've always heard these terms used interchangeably. I figured that "settling with power" was what the pilot did to cause the vortex ring state (VRS). But comments on another question indicate that ...
TomMcW's user avatar
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8 votes
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What are the symptoms of vortex ring state?

What are the signs and symptoms a pilot can recognize, that the helicopter is approaching vortex ring state (VRS) and measures should be taken? A related question discusses how to prevent or recover ...
kevin's user avatar
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How do modern helicopters tackle Vortex Ring State?

According to the wikipedia page : Air vortices can form around the main rotor of a helicopter, causing a dangerous condition known as vortex ring state (VRS) or "settling with power". In this ...
Victor Juliet's user avatar