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The vortex ring state (VRS) is a dangerous aerodynamic condition that may arise in helicopter flight, when a vortex ring system engulfs the rotor, causing severe loss of lift. Often the term settling with power is used as a synonym, e.g., in Australia, the UK, and the US, [ 2 ] [ 3 ] [ 4 ] but not in Canada, which uses the latter term for a ...
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 .
This resulted in the quadcopter configuration becoming popular for small unmanned aerial vehicles. With their small size and maneuverability, these quadcopters can be flown indoors as well as outdoors. [1] [22] For small drones, quadcopters are cheaper and more durable than conventional helicopters due to their mechanical simplicity. [23]
The toroidal ring model, known originally as the Parson magneton or magnetic electron, is a physical model of subatomic particles. It is also known as the plasmoid ring, vortex ring, or helicon ring. This physical model treated electrons and protons as elementary particles, and was first proposed by Alfred Lauck Parson in 1915.
A second "vortex ring" parachute then deploys to slowly spin the submunition, suspending it at approximately 30° from the vertical. As it spins, its sensors sweep a decreasing spiral track beneath the submunition to scan an area about 150 m in diameter.
Each vortex creates a circular (ring) flow field whose axis varies slightly from the vertical as it passes. The figure suggests that the main component of the force on the physical ring is in the direction of the jet flow. If the vortex is a true ring (all parts are in phase), a dipole sound field directed along the jet axis is created.
Main rotor disk vortex interference Weathercock stability Tail rotor vortex ring state. Loss of tail-rotor effectiveness (LTE) [1] occurs when the tail rotor of a helicopter is exposed to wind forces that prevent it from carrying out its function—that of cancelling the torque of the engine and transmission. Any low-airspeed high-power ...
Hill's spherical vortex is an exact solution of the Euler equations that is commonly used to model a vortex ring. The solution is also used to model the velocity distribution inside a spherical drop of one fluid moving at a constant velocity through another fluid at small Reynolds number. [ 1 ]