A numerical study on the effect of second harmonics in the perturbation to the Belousov–Zhabotinsky system

The effect of a second harmonic component in the periodic perturbation on 1:1 phase entrainment is studied by numerical calculations of the three-variable Oregonator, a numerical model of the Belousov–Zhabotinsky (BZ) reaction. The phase difference Ψ between the autonomous system and the periodic perturbation with and without the second harmonic is determined. The role of this harmonic is to deviate the entrained phase difference. An increase in its amplitude causes bistability in the entrained state, which corresponds to the co-existence of the in-phase and out-of-phase modes around one of the fixed phase points.