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Magnetohydrodynamics is a subject that
concerns itself with several branches of fundamental physics, in
particular electricity and magnetism, and thus makes a good
demonstration for the senior high school years. Magnetohydrodynamics, or
MHD for short, is an application of the Lorentz Force Law which can be
used to propel boats and such in an ionic solution, such as salty sea
water.
This type of propulsion unit is still
being considered as an efficient mode of transportation by some industries
of the world however there are still some major engineering problems to
overcome. For example the average magnetic field strength to propel a
freighter would have to be in the order of 8 to 20 teslas (a fridge
magnet, that you would find in your home, is only about 0.01 tesla!). A
way to overcoming this particular problem is through the use of high
temperature superconducting magnets.
This presentation will be primarily concerned with the theory behind the
operation of a magnetohydrodynamic propulsion mechanism that will propel a
model boat in a pool of salt water. The static display and the converted
model boat are a relatively inexpensive way to demonstrate some
fundamental theories of electricity and magnetism. The total cost should
not exceed the 200 dollar mark (depending on the resources available to
you). The presentation itself might have some added demonstrations
involving the relationship between electricity and magnetism (for example
to make an electromagnet out of a nail and some copper wire.), but in
general the core presentation is to explain, at a senior high school
level, the concept of magnetohydrodynamics. |