Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Chemistry4me on 20/06/2009 07:30:28

Title: Is it possible to alter the flow of water with a magnetic field?
Post by: Chemistry4me on 20/06/2009 07:30:28
Can magnetic fields have an effect on the flow of water?
Title: Is it possible to alter the flow of water with a magnetic field?
Post by: Vern on 20/06/2009 18:37:20
It is called Magnetohydrodynamics (http://en.wikipedia.org/wiki/Magnetohydrodynamics).
The link is to a Wiki article about it. The water would need an additive to make it electrically conductive.

Quote from: the link
Magnetohydrodynamics (MHD) (magnetofluiddynamics or hydromagnetics) is the academic discipline which studies the dynamics of electrically conducting fluids. Examples of such fluids include plasmas, liquid metals, and salt water. The word magnetohydrodynamics (MHD) is derived from magneto- meaning magnetic field, and hydro- meaning liquid, and -dynamics meaning movement. The field of MHD was initiated by Hannes Alfvén[1], for which he received the Nobel Prize in Physics in 1970.

The idea of MHD is that magnetic fields can induce currents in a moving conductive fluid, which create forces on the fluid, and also change the magnetic field itself. The set of equations which describe MHD are a combination of the Navier-Stokes equations of fluid dynamics and Maxwell's equations of electromagnetism. These differential equations have to be solved simultaneously, either analytically or numerically. MHD is a continuum theory and as such it cannot treat kinetic phenomena, i.e. those in which the existence of discrete particles or of a non-thermal velocities distribution, are important.
Title: Is it possible to alter the flow of water with a magnetic field?
Post by: Chemistry4me on 21/06/2009 00:27:36
Thanks, so if I pass a current through some salt water (not that I'm planning to) it'll be affected by the magnetic field?
Title: Is it possible to alter the flow of water with a magnetic field?
Post by: Bored chemist on 21/06/2009 10:38:43
Also, water is diamagnetic, a strong enough field gradient will repel it.