FEMM 4.2 02Mar2007
David Meeker
dmeeker@ieee.orgNew in FEMM 4.2:
- Incorporates a new problem type for conduction problems encompassing both DC and AC conductivity, in addition to DC Magnetics, AC Magnetics, Electrostatics, and Heat Flow.
- Incorporates ComplexLua, a modified verison of the Lua scripting language in which the default number type is complex (rather than double). Modifications resulting from this change are:
- There are no longer separate edit boxes for the real and complex parts of complex-valued parameters (e.g. source current density in the material properties dialog for magnetic problems). Instead, there is a single edit box in which a complex number can be entered.
- No longer need to separately specify real and imaginary parts of complex numbers in Lua function calls--these parameters are now rolled into one complex-valued parameter
- Real and imaginary parts no longer returned separately by Lua functions; they now return complex values as appropriate.
- Can include complex math in Lua scripts. All standard math functions have been modified to yield correct answers for complex-values arguments.
- The setcompatibilitymode(1) command can be used to temporarily revert to the lua function definitions as defined in FEMM 4.0.
- However, Matlab, Mathematica, and Octave interfaces are unchanged from the user's perspective. These interfaces already collected and returned values as complex numbers. All Octave/Matlab scripts and Mathematica notebooks from FEMM 4.0 should work without modification in FEMM 4.2
- Additional math functions defined: arg, conj, sinh, cosh, tanh.
- Can define a magnetization direction as an equation, rather than a fixed value. For the purposes of defining the magnetization direction, the variables x, y, r, z and theta are built-in variables that are used to denote the location of the particular spot at which the magnetization is being defined. For example, to define a radial magnetization, one would enter theta into the block property dialog, rather than a fixed number.
- For magnetic problems, density plots allow field intensity (H) to be plotted, in addition to flux density (B) and current density (J).
- Incorporates a modified version of the continuum proximity/skin effect loss model deployed in FEMM 4.0. The version in FEMM 4.2 is based on a similar form, but parameters are selected to provide a best fit match to a battery finite element calculations. There is an improvement in accuracy as compared to the FEMM 4.0 approach, especially in the case of very high or very low fill factors.
The distribution also includes the
OctaveFEMM and
MathFEMM toolboxes for interfacing Octave/Matlab and Mathematica to FEMM. See the documentation in FEMM 4.2 folder of your Start menu for more details.