[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [femm] Force on a conductor?
emacoustics wrote:
Hey folks,
Once more I have come to pick your brains! If anyone remembers, I am
doing a project at Uni that involves simulating a loudspeaker voice
coil. What I would ideally like to do is to be able to plot a graph
of the force on the coil (or a point on the coil, for example the
leading edge) vs current in the coil. Is there a way of obtaining
the force at a point?
Well, the force density a point in the coil is J X B (where the X represents
the cross-product). Therefore, the easiest thing to do is to plot the radial
component of B, using the usual "X-Y plot" functionality. In the same dialog
box where you select what type of plot you want to make, there is also a
check box that you can select so that the data gets written to disk instead
of plotted to the screen. You can write the data to disk; slurp it into
mathcad, matlab, mathematica, or (insert your favorite program here); multiply
all the B values on the line by the J carried by the coil; and plot this
modified result.
If you want to get more complicated, you can compute J X B inside a Lua script
and then write that to disk.
Also, can FEMM output and input numerically? For example running two
simulations, outputting numerical results to sum the two together (ie
superposition) and then inputting them back into FEMM as a data
file? If so, how do I do it?
You can do things like this through the use of Lua scripting. It's described
some in the manual, and there are some examples on the website at femm.berlios.de/examples.htm
However, you may have to get creative to do exactly what you are after.
Dave.