  The chaotic properties of simple two-dimensional rotation-translation models
are explored and simulated. The models are given in difference equation forms,
while the corresponding differential equations systems are studied and the
resulting trajectories in the plane are explored and illustrated in the
computer experiments done. Characteristic patterns, egg-shaped forms and
central chaotic bulges are present when particles are introduced in the
rotating system. The resulting forms and chaotic attractors mainly depend on
the form of the nonlinear function expressing the rotation angle. Several cases
are studied corresponding to a central force rotation system.
