Dynamic mode decomposition analysis of detonation waves

作者：Massa L^*; Kumar R; Ravindran P

来源：Physics of Fluids, 2012, 24(6): 066101.

DOI：10.1063/1.4727715

• chaos
• detonation waves
• flow instability
• fluctuations
• fluid oscillations
• Mach number
• turbulence

Dynamic mode decomposition is applied to study the self-excited fluctuations supported by transversely unstable detonations. The focus of this study is on the stability of the limit cycle solutions and their response to forcing. Floquet analysis of the unforced conditions reveals that the least stable perturbations are almost subharmonic with ratio between global mode and fundamental frequency lambda(i)/omega(f)=0.47. This suggests the emergence of period doubling modes as the route to chaos observed in larger systems. The response to forcing is analyzed in terms of the coherency of the four fundamental energy modes: acoustic, entropic, kinetic, and chemical. Results of the modal decomposition suggest that the self-excited oscillations are quite insensitive to vortical forcing, and maintain their coherency up to a forcing turbulent Mach number of 0.3.

• 出版日期2012-6