DYNAMICS OF THE 2-FREQUENCY TORUS BREAKDOWN IN THE DRIVEN DOUBLE SCROLL CIRCUIT

In work we numerically identify three scenarios for the two-frequency torus breakdown to chaos, using the driven double scroll circuit, with varying driving parameters. Two of these scenarios follow the Curry-Y orke route to chaos. For one scenario, we identify the transition to c haos through the onset of a heteroclinic tangle and its heteroclinic p oints. In the other scenario, chaos appears via period-doubling bifurc ations. The third scenario is through the type-II intermittency for wh ich a quasiperiodic torus grows in size, breaks by touching external s addle points, and forms a heteroclinic saddle connection. These dynami c scenarios have distinct structure evolutions: for the Curry-Yorke ro ute, chaos appears softly and alternates with phase locking, while, fo r the type-II intermittency, chaos appears abruptly and is pn:served f or a large range of the varying driving parameter. [S1063-651X(98)0521 0-6].