  Triple flickering buoyant diffusion flames in an isosceles triangle
arrangement were experimentally studied as a nonlinear dynamical system of
coupled oscillators. The objective of the study is two-fold: to establish a
well-controlled gas-fuel diffusion flame experiment that can remedy the
deficiencies of previous candle-flame experiments, and to develop an objective
methodology for dynamical mode recognition that is based on the Wasserstein
distance between distribution functions of phase points and can be readily
generalized to larger dynamical system consisting of more than three flames. By
using the present experiment and methodology, we recognized seven distinct
stable dynamical modes, such as in-phase mode, flickering death mode, partial
flickering death mode, partial in-phase mode, rotation mode, partial decoupled
mode, and decoupled mode. These results generalize the literature results for
triple flickering flame system in a straight-line and equal-lateral triangle
arrangement. The identification or discrimination of two dynamical modes can be
quantified as the small or large Wasserstein distance, respectively.
