Space-time description of the splitting and coalescence of wave fronts in film flows

[摘要] Simultaneous space-time measurements of two-dimensional waves on the surface of a flowing film are recorded using a fluorescence imaging method and analyzed by means of both Fourier and biorthogonal decomposition techniques. The analysis, performed at various Reynolds numbers and perturbation frequencies, reveals that the splitting and coalescence of wavefronts is due to purely spatial modulations of the original uniformly traveling wave. The modulations cannot be described by a single modulating function. A phase space description of this change in the dynamics is given, and the effect of the modulations on the global entropy function is discussed. At higher Reynolds number, the modulations are both spatial and temporal.

[发布日期] 1996-09-15

[效力级别]  Proceedings Paper