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Related papers: Instability of particulate pipe flow

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In the linear theory of hydrodynamic stability up to now there exist examples of flows for which there is full quantitative distinction, as for cylindrical Hagen-Poiseuille (HP) flow in a pipe with round section, between theory conclusions…

Fluid Dynamics · Physics 2025-02-04 Sergey G. Chefranov , Alexander G. Chefranov

We compare experiments and direct numerical simulations to evaluate the accuracy of the Stokes-drag model, which is used widely in studies of inertial particles in turbulence. We focus on statistics at the dissipation scale and on extreme…

The evolution of the filamentation instability produced by two counter-streaming pair plasmas is studied with particle-in-cell (PIC) simulations in both one (1D) and two (2D) spatial dimensions. Radiation friction effects on particles are…

Plasma Physics · Physics 2015-09-16 M. D'Angelo , L. Fedeli , A. Sgattoni , F. Pegoraro , A. Macchi

Particle motion is considered in incompressible two-dimensional flows consisting of a steady background gyre on which an unsteady wave-like perturbation is superimposed. A dynamical systems point of view that exploits the action--angle…

Fluid Dynamics · Physics 2020-01-29 Francisco J. Beron-Vera , María J. Olascoaga , Michael G. Brown

This paper addresses the stability of plane Couette flow in the presence of strong density and viscosity stratifications. It demonstrates the existence of a generalised inflection point that satisfies the generalised Fjortoft's criterion of…

Fluid Dynamics · Physics 2024-06-13 B. Bugeat , P. C. Boldini , A. M. Hasan , R. Pecnik

We present experimental evidence of multiple blood flow configurations in a relatively simple microfluidic network under constant inlet conditions. We provide evidence of multistability and unsteady dynamics and find good agreement with a…

The dynamics of inertial particles in turbulence is modelled and investigated by means of direct numerical simulation of an axisymmetrically expanding homogeneous turbulent strained flow. This flow can mimic the dynamics of particles close…

Fluid Dynamics · Physics 2023-07-19 Chung-min Lee , Ármann Gylfason , Prasad Perlekar , Federico Toschi

The Rayleigh capillary instability of a cylindrical interface between two immiscible fluids is one of the most fundamental in fluid dynamics. As Plateau observed from energetic considerations and Rayleigh clarified through hydrodynamics,…

Soft Condensed Matter · Physics 2009-10-30 Thomas R. Powers , Dengfu Zhang , Raymond E. Goldstein , Howard A. Stone

We revisit, via a very simplified set of equations, a linear streaming instability (technically an overstability), which is present in, and potentially important for, dusty protoplanetary disks (Youdin & Goodman 2005). The goal is a better…

Earth and Planetary Astrophysics · Physics 2015-05-28 Emmanuel Jacquet , Steven A. Balbus , Henrik N. Latter

Particle scattering and vacuum instability in a constant inhomogeneous electric field of particular peak configuration that consists of two (exponentially increasing and exponentially decreasing) independent parts are studied. It presents a…

High Energy Physics - Theory · Physics 2017-11-22 S. P. Gavrilov , D. M. Gitman , A. A. Shishmarev

Shocks in granular media, such as vertically oscillated beds, have been shown to develop instabilities. Similar jet formation has been observed in explosively dispersed granular media. Our previous work addressed this instability by…

Fluid Dynamics · Physics 2014-07-17 Nick Sirmas , Sam Falle , Matei Radulescu

In a recent article (Forterre, PRL, 2001), we have reported a new instability observed in rapid granular flows down inclined planes that leads to the spontaneous formation of longitudinal vortices. From the experimental observations, we…

Soft Condensed Matter · Physics 2009-11-07 Yoel Forterre , Olivier Pouliquen

We analyze the stability and dynamics of toroidal liquid droplets. In addition to the Rayleigh instabilities akin to those of a cylindrical droplet there is a shrinking instability that is unique to the topology of the torus and dominates…

Soft Condensed Matter · Physics 2015-03-17 Zhenwei Yao , Mark Bowick

We investigate the effect of inertial particles dispersed in a circular patch of finite radius on the stability of a two-dimensional Rankine vortex in semi-dilute dusty flows. Unlike the particle-free case where no unstable modes exist, we…

Fluid Dynamics · Physics 2022-10-05 Shuai Shuai , Darish Jeswin Dhas , Anubhab Roy , M. Houssem Kasbaoui

Two-dimensional Stokes flow with injection and suction is investigated through a second-order, perturbative mode-coupling approach. We examine the time-dependent disturbance of an initially circular interface separating two viscous fluids,…

Fluid Dynamics · Physics 2020-10-08 Gabriel Dias Carvalho , Rodolfo Brandão , José A. Miranda

Finite-size neutrally buoyant particles in a channel flow are known to accumulate at specific equilibrium positions or spots in the channel cross-section if the flow inertia is finite at the particle scale. Experiments in different conduit…

Fluid Dynamics · Physics 2018-10-23 Anupam Gupta , Pascale Magaud , Christine Lafforgue , Micheline Abbas

We investigate experimentally the influence of suspended particles on the transition to turbulence. The particles are monodisperse and neutrally-buoyant with the liquid. The role of the particles on the transition depends both upon the pipe…

Fluid Dynamics · Physics 2009-11-10 Jean-Philippe Matas , Jeffrey F. Morris , Elisabeth Guazzelli

This study is concerned with the statistics of vertical turbulent channel flow laden with inertial particles for two different volume concentrations ($\Phi_{V} = 3 \times 10^{-6}$ and $\Phi_{V} = 5 \times 10^{-5}$) at a Stokes number of…

Fluid Dynamics · Physics 2019-04-22 Guiquan Wang , Kee Onn Fong , Filippo Coletti , Jesse Capecelatro

We use Stokesian Dynamics simulations to study the microscopic motion of particles suspended in fluids passing through porous media. We construct model porous media with fixed spherical particles, and allow mobile ones to move through this…

Disordered Systems and Neural Networks · Physics 2009-10-31 Jysoo Lee , Joel Koplik

We analyzed formation of small-scale inhomogeneities of particle spatial distribution (particle clustering) in a turbulent flow. The particle clustering is a consequence of a spontaneous breakdown of their homogeneous space distribution,…