Many folks have successfully modeled all versions of the Hex Beam. Most of the simulation attempts use NEC programs.
Despite being a popular and productive way of simulating amateur radio antennas, another method of electromagnetic simulation makes use of the Finite-Difference Time Domain (FDTD) method.
Without going into too many details, the method divides up the simulation space into little cubes of volume. Then the next magnetic field values are derived from the current electric fields. Then the next electric field values are derived from the current magnetic fields. Repeat.
FDTD makes use of Maxwell’s equations to calculate the above fields. Being a Time Domain method, what follows shows a movie like display of what is happening in the antennas in super slow motion.