Duality of diffusion dynamics in particle motion in soft-mode turbulence

Suzuki, Masaru; Sueto, Hiroshi; Hosokawa, Yusaku; Muramoto, Naoyuki; Narumi, Takayuki; Hidaka, Yoshiki; Kai, Shoichi

doi:10.1103/physreve.88.042147

Cited by 9 publications

(3 citation statements)

References 14 publications

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“…The time scale rapidly decreases at larger length scales k < k Γ , indicating inter-patch dynamics does not affect the memory effect due to TFs. Some work does support the relationship between the patch structure and the dual structure [17,28,31], where the dynamics of a tagged has a local maximum. The gray dashed line marks the line fit, k 2 Γ = c0 + c1ε with c0 = 0.0045 and c1 = 0.052.…”

Section: Characteristic Time Scalesmentioning

confidence: 99%

Memory function of turbulent fluctuations in soft-mode turbulence

et al. 2013

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Modal relaxation dynamics has been observed experimentally to clarify statistical-physical properties of softmode turbulence, the spatiotemporal chaos observed in homeotropically aligned nematic liquid crystals. We found a dual structure, dynamical crossover associated with violation of time-reversal invariance, the corresponding time scales satisfying a dynamical scaling law. To specify the origin of the dual structure, the memory function due to non-thermal fluctuations has been defined by a projection-operator method and obtained numerically using experimental results. The results of the memory function suggest that the non-thermal fluctuations can be divided into Markov and non-Markov contributions, the latter is called the turbulent fluctuation (TF). Consequently, the relaxation dynamics is separated into three characteristic stages: bare-friction, early, and late stages. If the dissipation due to TFs dominates over that of the Markov contribution, the bare-friction stage contracts; the early and late stages then configure the dual structure. The memory effect due to TFs results in the time-reversible relaxation at the early stage, and the disappearance of the memory by turbulent mixing leads to a simple exponential relaxation at the late stage. Furthermore, the memory effect due to TFs is shown to originate from characteristic spatial coherency called the patch structure.

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Section: Characteristic Time Scalesmentioning

confidence: 99%

Memory function of turbulent fluctuations in soft-mode turbulence

et al. 2013

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“…Research aimed at elucidating the transport phenomena arising from soft-mode turbulence has been performed from both the Euler [14] and Lagrange viewpoints. In particular, for the Lagrangian viewpoint, a method called nonthermal Brownian motion has been used that measures the motion of isolated particles and analyses the motion from the analogy with Brownian motion [15][16][17][18][19][20][21]. In the planar system, defect turbulence (see Figure 1) occurs in which defects embedded in the convective stripe pattern nucleate by fluctuations of the convective rolls [22].…”

Section: Introductionmentioning

confidence: 99%

“…The time-dependent diffusion coefficient is suitable for extracting properties of the diffusion in systems containing such a hierarchy. The time-dependent diffusion coefficient had been already applied to nonthermal Brownian motion in soft-mode turbulence [16,18]. Aside from weak turbulence, biological systems are examples of systems with a hierarchy.…”

Section: Introductionmentioning

confidence: 99%

Time-Dependent Diffusion Coefficients for Chaotic Advection due to Fluctuations of Convective Rolls

Yamanaka

Narumi²,

Hashiguchi³

et al. 2018

Fluids

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The properties of chaotic advection arising from defect turbulence, that is, weak turbulence in the electroconvection of nematic liquid crystals, were experimentally investigated. Defect turbulence is a phenomenon in which fluctuations of convective rolls arise and are globally disturbed while maintaining convective rolls locally. The time-dependent diffusion coefficient, as measured from the motion of a tagged particle driven by the turbulence, was used to clarify the dependence of the type of diffusion on coarse-graining time. The results showed that, as coarse-graining time increases, the type of diffusion changes from superdiffusion → subdiffusion → normal diffusion. The change in diffusive properties over the observed timescale reflects the coexistence of local order and global disorder in the defect turbulence.

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Topological defects and electro-convective flows in anisotropic fluids: A microfluidic platform for nano-objects tunable structuring

Provenzano

Mazzulla

Chiaravalloti

et al. 2016

Applied Physics Letters

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Anisotropic fluids are a class of soft materials that offer wide possibilities for engineering a small scale laboratory; their physical properties can be manipulated on short length scale by appropriate confining conditions and external stimuli leading the systems across fascinating phenomena. In this work, two of these phenomena are combined to create a microfluidic platform for reconfigurable nanoparticles (NPs) patterning: the formation of topological defects and the electrically controlled convective flows. Here, the nanoscopic environments created by defects within liquid crystals have been used as linear nano-reservoirs of NPs. Afterwards, virtual channel flows that connect the linear reservoirs have been created by exploiting electro-convective rolls. The reported results reveal a strategy for managing nanometric objects based on anisotropic fluids and connected phenomena, proposing an unconventional microfluidic device characterized by switchable and contactless micro-channels.

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Duality of diffusion dynamics in particle motion in soft-mode turbulence

Cited by 9 publications

References 14 publications

Memory function of turbulent fluctuations in soft-mode turbulence

Memory function of turbulent fluctuations in soft-mode turbulence

Time-Dependent Diffusion Coefficients for Chaotic Advection due to Fluctuations of Convective Rolls

Topological defects and electro-convective flows in anisotropic fluids: A microfluidic platform for nano-objects tunable structuring

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