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A major obstacle for the understanding of long electrical discharges is the complex dynamics of streamer coronas, formed by many thin conducting filaments. Building macroscopic models for these filaments is one approach to attain a deeper…

Plasma Physics · Physics 2017-05-10 A. Luque , M. González , F. J. Gordillo-Vázquez

Off-diagonal (transverse) effects in micro-patterned geometries are predicted and analyzed within the general frame of linear response theory, relating applied presure gradient and electric field to flow and electric current. These effects…

Soft Condensed Matter · Physics 2009-11-07 Armand Ajdari

Ferrofluids kept in place by permanent magnet quadrupoles can act as liquid walls to surround a second non-magnetic inside, resulting in a liquid fluidic channel with diameter size ranging from mm down to less than 10 micrometer. Micro…

An experimental device has been built to measure velocity profiles and friction laws in channeled snow flows. The measurements show that the velocity depends linearly on the vertical position in the flow and that the friction coefficient is…

Classical Physics · Physics 2007-07-23 Marie Rastello , Alexi Bouchet

The behavior of particles driven through a narrow constriction is investigated in experiment and simulation. The system of particles adapts to the confining potentials and the interaction energies by a self-consistent arrangement of the…

Soft Condensed Matter · Physics 2008-10-15 P. Henseler , A. Erbe , M. Köppl , P. Leiderer , P. Nielaba

In this paper, we investigate steady Euler flows in a two-dimensional bounded domain. By an adaption of the vorticity method, we prove that for any nonconstant harmonic function $q$, which corresponds to a nontrivial irrotational flow,…

Analysis of PDEs · Mathematics 2019-10-16 Daomin Cao , Guodong Wang , Zhan Weicheng

Inertial fluid flow deformation around pillars in a microchannel is a new method for controlling fluid flow. Sequences of pillars have been shown to produce a rich phase space with a wide variety of flow transformations. Previous work has…

We analyse the intersection of positively and negatively sectional-hyperbolic sets for flows on compact manifolds. First we prove that such an intersection is hyperbolic if the intersecting sets are both transitive (this is false without…

Dynamical Systems · Mathematics 2014-10-03 S. Bautista , C. A. Morales

The transition to turbulence in a precessing cylindrical vessel is experimentally investigated. Our measurements are performed for a { nearly-resonant} configuration with an initially laminar flow dominated by an inertial mode with…

Fluid Dynamics · Physics 2016-01-20 Johann Herault , Thomas Gundrum , Andre Giesecke , Frank Stefani

The aim of this paper is to present a kinetic numerical scheme for the computations of transient pressurised flows in closed water pipes with variable sections. Firstly, we detail the derivation of the mathematical model in curvilinear…

Analysis of PDEs · Mathematics 2008-12-02 Christian Bourdarias , Mehmet Ersoy , Stéphane Gerbi

A thin gaseous disc with an almost keplerian angular velocity profile, bounded by a free surface and rotating around point-mass gravitating object is nearly spectrally stable. Despite that the substantial transient growth of linear…

High Energy Astrophysical Phenomena · Physics 2015-05-30 Dmitry Razdoburdin , Viacheslav Zhuravlev

We investigate the stability of the pressure-driven, low-Reynolds flow of Brownian suspensions with spherical particles in microchannels. We find two general families of stable/unstable modes: (i) degenerate modes with symmetric and…

Fluid Dynamics · Physics 2015-06-04 Atefeh Khoshnood , Mir Abbas Jalali

We study the notion of stochastic stability with respect to diffusive perturbations for flows with smooth invariant measures. We investigate the question fully for non-singular flows on the circle. We also show that volume-preserving flows…

Dynamical Systems · Mathematics 2011-12-02 Sergiu Aizicovici , Todd Young

We consider the mean curvature flow of compact convex surfaces in Euclidean $3$-space with free boundary lying on an arbitrary convex barrier surface with bounded geometry. When the initial surface is sufficiently convex, depending only on…

Analysis of PDEs · Mathematics 2020-01-07 Sven Hirsch , Martin Li

In 1965, B. A. Troesch solved the isoperimetric sloshing problem of determining the container shape that maximizes the fundamental sloshing frequency among two classes of shallow containers: symmetric canals with a given free surface width…

Spectral Theory · Mathematics 2022-07-22 Chee Han Tan , Christel Hohenegger , Braxton Osting

Stabilization schemes in wall-bounded flows often invoke fluid transpiration through porous boundaries. While these have been extensively validated for external flows, their efficacy in channels, particularly from the standpoint of…

Fluid Dynamics · Physics 2024-04-24 Muhammad Abdullah , George Ilhwan Park

We study the surface diffusion flow acting on a class of general (non--axisymmetric) perturbations of cylinders $\mathcal{C}_r$ in ${\rm I \! R}^3$. Using tools from parabolic theory on uniformly regular manifolds, and maximal regularity,…

Analysis of PDEs · Mathematics 2016-06-01 Jeremy LeCrone , Gieri Simonett

We consider a compact, star-shaped, mean convex hypersurface $\Sigma^2\subset \mathbb{R}^3$. We prove that in some cases the flow exists until it shrinks to a point in a spherical manner, which is very typical for convex surfaces as well…

Differential Geometry · Mathematics 2008-09-03 Panagiota Daskalopoulos , Natasa Sesum

We investigate the formation of acoustic horizons for an inviscid fluid moving in a pipe in the case of stationary and axi-symmetric flow. We show that, differently from what is generally believed, the acoustic horizon forms in…

Fluid Dynamics · Physics 2015-06-26 M. Cadoni , P. Pani

The application of oscillatory flow around an obstacle drives a steady ``streaming'' due to inertial rectification, which has been used in a host of microfluidic applications. While theory has focused largely on two-dimensional (2D) flows,…

Fluid Dynamics · Physics 2023-05-10 Xirui Zhang , Bhargav Rallabandi