This neat magnetohydrodynamic (MHD) demo is one we do not suggest repeating at home. The high voltage applied across the magnets and the plate causes the white disk in between to vaporize and form a plasma. Then the magnetic field causes the circumferential motion via the Lorentz force, essentially trapping the plasma and making it spin.
Tag: magnetohydrodynamics
Calcium Plasma on the Sun
This high-resolution photo of our sun shows the structure of calcium plasma on the surface of the sun. Plasmas are governed by the same physics as our familiar earthbound fluids but are also extremely sensitive to magnetic fields. Their branch of fluid dynamics is often referred to as magnetohydrodynamics (MHD), where the Navier-Stokes equations have to be solved in conjunction with Maxwell’s equations. (via Bad Astronomy)
Stirring with Electromagnetism
If a fluid is electrically conductive, then magnetohydrodynamics (often abbreviated as MHD) describe its behavior. Electric and magnetic fields can be used to stir such a fluid, as in the video above. By inducing a potential difference across the electrodes lining the walls and the disk-shaped electrodes far from the walls, complicated flow patterns can be produced. #
Magnetohydrodynamics
Fluid dynamics play an important role in understanding phenomena like sunspots and solar prominences. The subfield of fluid dynamics concerned with the motion of electrically conducting fluids, like the plasma that makes up the sun’s corona, is magnetohydrodynamics.
Ferrofluid Art
Magnetism and fluid dynamics collide with ferrofluids! Ferrofluids are a suspension of ferrous material in oil or water, but their behavior around magnets can elevate them into a work of art (or a car commercial). Why leave it to professionals, though, when you can make your own ferrofluid?
