The green vortex generator s prompt the transition to turbulent flow and prevent back-flow also called flow separation from the high pressure region in the back.

Uniform flow plus vortex flow ( circulation ) gives the total flow below.

In particular, solutions can be expressed as the sum of a uniform flow ( i. e. a steady flow equal to the free stream velocity ) plus a free vortex flow, i. e. a circular flow around the airfoil with the speed inversely proportional to the radius.

The magnitude of the vortex flow is adjusted so that the Kutta condition is met.

The physical interpretation of circulation is that the vortex flow adds to the uniform flow above the wing and subtracts from it below the wing.

The flow in the vicinity of the sharp trailing edge is very fast and the resulting viscous forces cause the boundary layer to accumulate into a vortex on the upper side of the airfoil between the trailing edge and the upper stagnation point.

As the starting vortex increases in strength the bound vortex also strengthens, causing the flow over the upper surface of the airfoil to accelerate and drive the upper stagnation point towards the sharp trailing edge.

If the flow were stopped, there would be a corresponding " stopping vortex ".

For instance, the flow around a circular cylinder generates a Kármán vortex street: vortices being shed in an alternating fashion from each side of the cylinder.

This design produces a continuous flow with equal volume and no vortex.

In Type II superconductors, raising the applied field past a critical value H < sub > c1 </ sub > leads to a mixed state ( also known as the vortex state ) in which an increasing amount of magnetic flux penetrates the material, but there remains no resistance to the flow of electric current as long as the current is not too large.

The whistle works by causing the smooth flow of air to be split by a narrow blade, sometimes called a labium or windcutter, creating a turbulent vortex which causes the air to vibrate.

The secondary flow in the dust devil causes other hot air to speed horizontally inward to the bottom of the newly forming vortex.

The flow field around an airplane is a vector field in R < sup > 3 </ sup >, here visualized by bubbles that follow the Streamlines, streaklines, and pathlines | streamline s showing a wingtip vortex.

There exists a link between sudden stratospheric warmings and the quasi-biennial oscillation: If the QBO is in its easterly ( westward ) phase, the atmospheric waveguide is modified in such a way that upward-propagating Rossby waves are focused on the polar vortex, intensifying their interaction with the mean flow.

However, any simply connected subset that excludes the vortex line ( 0, 0, z ) will have zero curl, ∇× v = 0.

The term gyre can be used to refer to any type of vortex in the air or the sea, even one that is man-made, but it is most commonly used in oceanography to refer to the major ocean systems.

As in any vortex, the velocity of the fluid is roughly constant except near the core, so that the angular velocity increases towards the core, and most of the vorticity ( and hence most of the energy dissipation ) is concentrated near it.

Other forms of energy would in any case be required for the compression of the air feeding the vortex ( e. g. fuel or coal combustion ).

The same phenomenon occurs with any fluid, creating vortex rings which are invisible but otherwise entirely similar to smoke rings.

The number of possible positions of any vortex in the system is approximately.

These punctures are called vortices and if γ is a closed path which only winds once counterclockwise around the puncture and its winding number about any other puncture is zero, then the integer multiplicity can be attached to the vortex itself.

At a time when the Cartesian system of vortices universally prevailed, he found it necessary to investigate that hypothesis, and in the course of his investigations he showed that the velocity of any stratum of the vortex is an arithmetical mean between the velocities of the strata which enclose it ; and from this it evidently follows that the velocity of a filament of water moving in a pipe is an arithmetical mean between the velocities of the filaments which surround it.

In his paper Helmholtz established his three " laws of vortex motion " in much the same way one finds them in any advanced textbook of fluid mechanics today.

A vortex ring toy is any of several toys that generate vortex rings – rolling torus-shapes of fluid, similar in structure to smoke rings – that move through the fluid ( most often air, and sometimes water ).

The figure shows the velocity () induced at a point P by an element of vortex filament () of strength.

In Maxwell's 1861 paper ' On Physical Lines of Force ', magnetic field strength H was directly equated with pure vorticity ( spin ), whereas B was a weighted vorticity that was weighted for the density of the vortex sea.

where Γ is the strength of the vortex and r is the perpendicular distance between the point and the vortex line.

The ' strength ' of a vortex-tube ( also called vortex flux ) is the integral of the vorticity across a cross-section of the tube, and is the same at everywhere along the tube ( because vorticity has zero divergence ).

It is a consequence of Helmholtz's theorems ( or equivalently, of Kelvin's circulation theorem ) that in an inviscid fluid the ' strength ' of the vortex tube is also constant with time.

This might seem paradoxical because installation of vortex generators does not increase the strength of the wing.

) because the vortex strength grows with the aircraft lift coefficient, and thus the associated turbulence is greatest at low speed and high weight.

: The strength of a vortex filament is constant along its length.

The strength of a vortex tube does not vary with time .< ref >

The strength of a vortex tube ( circulation ), is defined as:

The intensity or strength of the vortex is a function of aircraft size, speed, and configuration ( flap setting, etc .).

In the southern hemisphere, it tends to be located near the edge of the Ross ice shelf near 160 west longitude .< ref > When the polar vortex is strong, the Westerlies increase in strength.

When the polar vortex is strong, the Westerlies increase in strength.

It has been shown that the main parameters governing the strength of a BVI are the distance between the blade and the vortex, the vortex strength at the time of the interaction, and how parallel or oblique the interaction is ( Hardin 1987, Malovrh 2005 ).

This lift may be steady, or it may oscillate due to vortex shedding.

Interaction of the object's flexibility with the vortex shedding may enhance the effects of fluctuating lift and cause vortex-induced vibrations.

Ultrasonic measurements may be limited through barrier layers with large salinity, temperature or vortex differentials.

They are often quite scary spirits, and parents may warn their children that if they misbehave, a spirit will emerge from the spinning vortex of dirt and chastise them.

Low densities may cause an extinction vortex and lead to further reduced fertility.

For instance, the lift distribution over a finite wing may be approximated by assuming that each segment of the wing has a semi-infinite trailing vortex behind it.

One theory that may account for the wide spectrum of observational evidence is the idea of combustion inside the low-velocity region of spherical vortex breakdown of a natural vortex ( e. g., the ' Hill's spherical vortex ').

Depending on the column gradient of temperature and pressure, or buoyancy, and stability of the vortex, very high-altitude updraft may be achievable.

A super-particle ( or macroparticle ) is a computational particle that represents many real particles ; it may be millions of electrons or ions in the case of a plasma simulation, or, for instance, a vortex element in a fluid simulation.

Cosmetic ocular involvement may be present showing cornea verticillata ( also known as vortex keratopathy ), i. e. clouding of the corneas.

Keratopathy may be the presenting feature in asymptomatic carriers, and must be differentiated from other causes of vortex keratopathy ( e. g. drug deposition in the cornea ).

It is theorized that the vortex may be a form of life.

The setbacks and rounded edges of the building combat vortex formation which may occur in the " Windy City ".

One way a vortex ring may be formed is by injecting a compact mass of fast moving fluid ( A ) into a mass of stationary fluid ( B ) ( which may be the same fluid ).

For many purposes a ring vortex may be approximated as having a vortex-core of small cross-section.

A Kelvin wave ( fluid dynamics ) is also a long scale perturbation mode of a vortex in superfluid dynamics ; in terms of the meteorological or oceanographical derivation, one may assume that the meridional velocity component vanishes ( i. e. there is no flow in the north – south direction, thus making the momentum and continuity equations much simpler ).

Using vortex tube energy separation may be a method to recover waste pressure energy from high and low pressure sources.

Smoke rings may also be formed by sudden bursts of fire ( such as lighting and immediately putting out a cigarette lighter ), by shaking a smoke source ( such as an incense stick ) up and down, by firing certain types of artillery, or by the use of special devices, such as vortex ring toys.

Thus, even though the local dew point inside the vortex cores is even lower than in the ambient air, the water vapor may nevertheless condense — if the formation of the vortex brings the local temperature below the new local dew point.