English
Related papers

Related papers: Mixing effectiveness depends on the source-sink st…

200 papers

The mixing efficiency of a flow advecting a passive scalar sustained by steady sources and sinks is naturally defined in terms of the suppression of bulk scalar variance in the presence of stirring, relative to the variance in the absence…

Fluid Dynamics · Physics 2011-05-03 Tiffany A. Shaw , Jean-Luc Thiffeault , Charles R. Doering

Multiscale mixing efficiencies for passive scalar advection are defined in terms of the suppression of variance weighted at various length scales. We consider scalars maintained by temporally steady but spatially inhomogeneous sources,…

Fluid Dynamics · Physics 2007-05-23 Charles R. Doering , Jean-Luc Thiffeault

An upper bound on the mixing efficiency is derived for a passive scalar under the influence of advection and diffusion with a body source. For a given stirring velocity field, the mixing efficiency is measured in terms of an equivalent…

Fluid Dynamics · Physics 2007-12-12 Jean-Luc Thiffeault , Charles R. Doering , John D. Gibbon

Mixing a passive scalar field by stirring can be measured in a variety of ways including tracer particle dispersion, via the flux-gradient relationship, or by suppression of scalar concentration variations in the presence of inhomogeneous…

Fluid Dynamics · Physics 2010-11-08 Zhi Lin , Katarína Bodová , Charles R. Doering

Mixing in open incompressible flows is studied in a model problem with inhomogeneous passive scalar injection on an inlet boundary. As a measure of the efficiency of stirring, the bulk scalar concentration variance is bounded and the bound…

Fluid Dynamics · Physics 2015-05-18 Jean-Luc Thiffeault , Charles R. Doering

We study the scale dependence of effective diffusion of fluid tracers, specifically, its dependence on the P\'{e}clet number, a dimensionless parameter of the ratio between advection and molecular diffusion. Here, we address the case that…

Fluid Dynamics · Physics 2022-04-13 Yohei Kono , Yoshihiko Susuki , Takashi Hikihara

We study diffusion and mixing in different linear fluid dynamics models, mainly related to incompressible flows. In this setting, mixing is a purely advective effect which causes a transfer of energy to high frequencies. When diffusion is…

Analysis of PDEs · Mathematics 2018-06-11 Michele Coti Zelati , Matias G. Delgadino , Tarek M. Elgindi

By using high molecular weight fluorescent passive tracers with different diffusion coefficients and by changing the fluid velocity we study dependence of a characteristic mixing length on the Peclet number, $Pe$, which controls the mixing…

Chaotic Dynamics · Physics 2009-11-10 T. Burghelea , E. Segre , V. Steinberg

We investigate the mixing properties of scalars stirred by spatially smooth, divergence-free flows and maintained by a steady source-sink distribution. We focus on the spatial variation of the scalar field, described by the {\it dissipation…

Fluid Dynamics · Physics 2015-05-27 Alexandros Alexakis , Alexandra Tzella

Mixing of binary fluids by moving stirrers is a commonplace process in many industrial applications, where even modest improvements in mixing efficiency could translate into considerable power savings or enhanced product quality. We propose…

Fluid Dynamics · Physics 2020-07-27 Maximilian F. Eggl , Peter J. Schmid

Incompressible flows can be effective mixers by appropriately advecting a passive tracer to produce small filamentation length scales. In addition, diffusion is generally perceived as beneficial to mixing due to its ability to homogenise a…

Fluid Dynamics · Physics 2018-04-20 Christopher J. Miles , Charles R. Doering

A passive scalar is advected by a velocity field, with a nonuniform spatial source that maintains concentration inhomogeneities. For example, the scalar could be temperature with a source consisting of hot and cold spots, such that the mean…

Fluid Dynamics · Physics 2007-12-12 Jean-Luc Thiffeault , G. A. Pavliotis

Discrete element method simulations of confined bidisperse granular shear flows elucidate the balance between diffusion and segregation that can lead to either mixed or segregated states, depending on confining pressure. Results indicate…

Soft Condensed Matter · Physics 2018-09-24 Alexander M. Fry , Paul B. Umbanhowar , Julio M. Ottino , Richard M. Lueptow

We study passive scalar mixing by parallel shear flows in the presence of weak molecular diffusion. We recover the sharp uniform-in-diffusivity mixing rate for shear flows with finitely many critical points, recently proven in [1]. Our…

Analysis of PDEs · Mathematics 2026-03-11 Kyle L. Liss , Kunhui Luan

We use numerical simulations to examine two-dimensional particle mixtures that strongly phase separate in equilibrium. When the system is externally driven in the presence of quenched disorder, plastic flow occurs in the form of meandering…

Statistical Mechanics · Physics 2009-11-13 A. Libal , C. Reichhardt , C. J. Olson Reichhardt

We are concerned with flow enhanced mixing of passive scalars in the presence of diffusion. Under the assumption that the velocity gradient is suitably integrable, we provide upper bounds on the exponential rates of enhanced dissipation.…

Analysis of PDEs · Mathematics 2022-11-24 Christian Seis

We quantitatively study the interaction between diffusion and mixing in both the continuous, and discrete time setting. In discrete time, we consider a mixing dynamical system interposed with diffusion. In continuous time, we consider the…

Analysis of PDEs · Mathematics 2019-05-22 Yuanyuan Feng , Gautam Iyer

Entropy scaling is a powerful technique that has been used for predicting transport properties of pure components over a wide range of states. However, modeling mixture diffusion coefficients by entropy scaling is an unresolved task. We…

Chemical Physics · Physics 2026-04-03 Sebastian Schmitt , Hans Hasse , Simon Stephan

Mixing describes the process by which solutes evolve from an initial heterogeneous state to uniformity under the stirring action of a fluid flow. Fluid stretching forms thin scalar lamellae which coalesce due to molecular diffusion. Owing…

Fluid Dynamics · Physics 2024-05-30 Joris Heyman , Tanguy Le Borgne , Philippe Davy , Emmanuel Villermaux

The mixing of binary fluids by stirrers is a commonplace procedure in many industrial and natural settings, and mixing efficiency directly translates into more homogeneous final products, more enriched compounds, and often substantial…

Fluid Dynamics · Physics 2022-08-12 Maximilian F. Eggl , Peter J. Schmid
‹ Prev 1 2 3 10 Next ›