Effects of two periodic perturbations on the oscillatory combustion of acetaldehyde

Abstract
Periodic perturbations are applied to the input rates of acetaldehyde and oxygen simultaneously in the combustion of acetaldehyde in a CSTR. With the two perturbations at the same frequency, we measure bistability in entrainment and hysteresis as a function of the phase shift between the two perturbations. The application of a perturbation in the flowrate of one reactant to the system already entrained to a perturbation of the flowrate of the second reactant can cause the system: to become quasiperiodic in both perturbations; to become entrained to both perturbations; to remain entrained, but not phase locked, to the first perturbation; or to become quasiperiodic in the first perturbation but entrained to the second perturbation. We measure the effects of frequency modulated and amplitude modulated acetaldehyde flowrate perturbations; the results compare well with predictions made by a five-variable thermokinetic model.