Concept
Instability
Related publications (132)
Stability of a liquid layer draining around a horizontal cylinder: Interplay of capillary and gravity forces
François Gallaire, Shahab Eghbali, Simeon Vladimirov Djambov
We study the drainage of a viscous liquid film coating the outside of a solid horizontal cylinder, where gravity acts vertically. We focus on the limit of large Ohnesorge numbers Oh, where inertia is negligible compared to viscous effects. We first study t ...
Amer Physical Soc2024Liquid film instability of an internally coated horizontal tube
François Gallaire, Edouard Boujo, Yves-Marie François Ducimetière, Shahab Eghbali
We study numerically and theoretically the gravity-driven flow of a viscous liquid film coating the inner side of a horizontal cylindrical tube and surrounding a shear-free dynamically inert gaseous core. The liquid-gas interface is prone to the Rayleigh-P ...
AMER PHYSICAL SOC2023Weakly nonlinear versus semi-linear models of the nonlinear evolution of the centrifugal instability
We carry out a weakly nonlinear analysis of the centrifugal instability for a columnar vortex in a rotating fluid, and compare the results to those of the semi-linear model derived empirically by Yim et al. (J. Fluid Mech., vol. 897, 2020, A34). The asympt ...
CAMBRIDGE UNIV PRESS2023Columnlike free-interface flows: symmetry breaking and linear instability
This thesis is dedicated to the analysis of a subclass of interfacial flows, columnlike free-interface flows, from two view angles: (i) the symmetry breaking under geometry-induced or external forces, (ii) their stability against infinitesimal disturbances ...
EPFL2023Development of the self-modulation instability of a relativistic proton bunch in plasma
Ambrogio Fasoli, Ivo Furno, Patrick Blanchard, Yanis Andrebe, Riccardo Agnello, Christine Stollberg, Sun Hee Kim, Alban Sublet, Shuai Liu
Self-modulation is a beam-plasma instability that is useful to drive large-amplitude wakefields with bunches much longer than the plasma skin depth. We present experimental results showing that, when increasing the ratio between the initial transverse size ...
2023Present design of the Steering Mirror Assembly (SMA) for ITER ECHUL
Timothy Goodman, René Chavan, Anastasia Xydou
In the ITER Tokamak, four Electron Cyclotron Heating Upper Launchers (ECHUL) are needed to control plasma instabilities at the rational surfaces, most importantly the q = 3/2 and q = 2/1 neoclassical tearing modes (NTMs). Each ECHUL is equipped with a set ...
ELSEVIER SCIENCE SA2023A weakly nonlinear amplitude equation approach to the bypass transition in the two-dimensional Lamb–Oseen vortex
François Gallaire, Yves-Marie François Ducimetière
We analytically derive an amplitude equation for the weakly nonlinear evolution of the linearly most amplified response of a non-normal dynamical system. The development generalizes the method proposed in Ducimetière et al. (J. Fluid Mech., vol. 947, 2022, ...
2023The dynamics of unsteady frictional slip pulses
Thibault Didier Roch, Fabian Barras
Self-healing slip pulses are major spatiotemporal failure modes of frictional systems, featuring a characteristic size L(t) and a propagation velocity c(p)(t) (t is time). Here, we develop a theory of slip pulses in realistic rate- and state-dependent fric ...
Washington2023Gyrokinetic simulation of short wavelength ion temperature gradient instabilities in the ADITYA-U tokamak
Laurent Villard, Emmanuel Lanti
In this work, linear and nonlinear collisionless electrostatic simulation studies of the standard and short wavelength ion temperature gradient mode (SWITG) for experimental profiles and parameters of ADITYA-U tokamak are performed using the linear global ...
IOP Publishing Ltd2023The effects of Prandtl number on the nonlinear dynamics of Kelvin-Helmholtz instability in two dimensions
It is known that the pitchfork bifurcation of Kelvin-Helmholtz instability occurring at minimum gradient Richardson number Ri(m) similar or equal to 1/4 in viscous stratified shear flows can be subcritical or supercritical depending on the value of the Pra ...
2021