Hydrodynamic interactions play a role in synchronized motions of coupled oscillators in fluids, and understanding the mechanism will facilitate development of applications in fluid mechanics. For example, synchronization phenomenon in two-phase flow will benefit the design of future microfluidic devices, allowing spatiotemporal control of microdroplet generation without additional integration of control elements. In this work, utilizing a characteristic oscillation of adjacent interfaces between two immiscible fluids in a microfluidic platform, we discover that the system can act as a coupled oscillator, notably showing spontaneous in-phase synchronization of droplet breakup. With this observation of in-phase synchronization, the coupled droplet generator exhibits a complete set of modes of coupled oscillators, including out-of-phase synchronization and nonsynchronous modes. We present a theoretical model to elucidate how a negative feedback mechanism, tied to the distance between the interfaces, induces the in-phase synchronization. We also identify the criterion for the transition from in-phase to out-of-phase oscillations.
The formation of spatiotemporal patterns in chemical systems can often be attributed to local and global interactions with the nonlinear kinetics, e. g., due to diffusion or an external constraint, respectively. We investigate the dynamics of an oscillatory chemical reaction on a ring of discrete elements, where the positive local coupling and negative global feedback can be varied independently to observe the emerging spatiotemporal patterns. With local coupling, the oscillations exhibit nearly in‐phase synchronization. When increasing the global negative feedback, a transition is seen from nearly sinusoidal phase profile oscillations through rotating and standing waves to amplitude death behavior. The experimental studies are interpreted with a kinetic model of nickel electrodissolution. The results demonstrate the presence of rich spatiotemporal patterns that can be obtained in a network with positive local and negative global interactions.
more » « less- NSF-PAR ID:
- 10053454
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Israel Journal of Chemistry
- Volume:
- 58
- Issue:
- 6-7
- ISSN:
- 0021-2148
- Page Range / eLocation ID:
- p. 753-761
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Methods We analyzed large‐scale intracranial electroencephalographic recordings in children with medically refractory epilepsy undergoing presurgical workup (
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