Search results
Results From The WOW.Com Content Network
This phenomenon is naturally observed behind large emergent rocks in swift-flowing rivers. An eddy is a movement of fluid that deviates from the general flow of the fluid. An example for an eddy is a vortex which produces such deviation. However, there are other types of eddies that are not simple vortices.
In fluid dynamics, eddy diffusion, eddy dispersion, or turbulent diffusion is a process by which fluid substances mix together due to eddy motion. These eddies can vary widely in size, from subtropical ocean gyres down to the small Kolmogorov microscales , and occur as a result of turbulence (or turbulent flow).
In electromagnetism, an eddy current (also called Foucault's current) is a loop of electric current induced within conductors by a changing magnetic field in the conductor according to Faraday's law of induction or by the relative motion of a conductor in a magnetic field. Eddy currents flow in closed loops within conductors, in planes ...
These warm waters within the eddy are attributed to the baroclinic clockwise motion that results in a piling up of water near the center, and a downward displacement of surface water to depth (downwelling). This phenomenon is referred to as Ekman pumping, resulting from a conservation of mass, vertical velocity, and the Coriolis force ...
This flattens isopycnals (reduces buoyancy forcing) and therefore slows down the mean flow. This phenomenon is known as eddy saturation. (a) Time series of the ACC (blue) and EKE (red) in an eddy saturated quasigeostrophic coupled ocean-atmosphere model with an applied with stress, which is increased with a step function by 50% (black).
Cause of skin effect. A main current I flowing through a conductor induces a magnetic field H.If the current increases, as in this figure, the resulting increase in H induces separate, circulating eddy currents I W which partially cancel the current flow in the center and reinforce it near the skin.
The frequency at which vortex shedding takes place for a cylinder is related to the Strouhal number by the following equation: = Where is the dimensionless Strouhal number, is the vortex shedding frequency (Hz), is the diameter of the cylinder (m), and is the flow velocity (m/s).
This is the basis of standard (pancake coil) ECT. NDT kits can be used in the eddy current testing process. [6] ECT has a very wide range of applications. Since ECT is electrical in nature, it is limited to conductive material. There are also physical limits to generating eddy currents and depth of penetration . [7]