Strange nonchaos in self-excited singing flames

We report the first experimental evidence of a strange nonchaotic attractor (SNA) in the natural dynamics of a self-excited laboratory-scale system. In the previous experimental studies, the birth of a SNA was observed in quasiperiodically forced systems; however, such evidence of a SNA in an autonomous laboratory system is yet to be reported. We discover the presence of a SNA between the attractors of quasiperiodicity and chaos through a fractalization route in a laboratory thermoacoustic system. The observed dynamical transitions from order to chaos via a SNA is confirmed through various nonlinear characterization methods prescribed for the detection of a SNA.