Spatiotemporal dynamics of turbulent coaxial jet analyzed by symbolic information-theory quantifiers and complex-network approach.

We numerically study the spatiotemporal dynamics of a turbulent coaxial jet in a model rocket engine combustor from the viewpoints of symbolic information-theory quantifiers and complex networks. The dynamic behavior of flow velocity undergoes a significant transition from a stochastic to chaotic state as the turbulent jet moves downstream. The small-world nature exists in the near field forming a stochastic state, whereas it disappears by the formation of a chaotic state in the far field. The dynamic behavior of hydrogen and oxygen concentrations in the far field also represents deterministic chaos. The simultaneous dynamic behavior with chaotic mixing forms the phase-synchronization state.