Synchronized oscillatory flows in two parallelly connected Starling resistors

We investigated the synchronization phenomena of the oscillatory flows in two parallelly connected Starling resistors, which are an ideal model system of two coupled collapsible tubes merging into a single tube downstream. The stable synchronization modes depended on the distance between the deformable region and the merging point; only an in-phase mode was stable for the large distance, in-phase and anti-phase modes were bistable for the middle distance, and again only an in-phase mode was stable for the small distance. An anti-phase mode became stable through the subcritical pitchfork bifurcation by decreasing the distance. Further decreasing the distance, the anti-phase mode became unstable through the subcritical Neimark-Sacker bifurcation. We also clarified the distance dependence of the amplitude and frequency for each stable synchronization mode.