Publications de Cristobal Manuel Arratia Martinez

Absolute/convective secondary instabilities and the role of confinement in free shear layers

François Gallaire, Saviz Mowlavi, Cristobal Manuel Arratia Martinez

We study the linear spatiotemporal stability of an infinite row of equal point vortices under symmetric confinement between parallel walls. These rows of vortices serve to model the secondary instability leading to the merging of consecutive (Kelvin-Helmho ...

2018

Mode selection in trailing vortices: harmonic response of the non-parallel Batchelor vortex

François Gallaire, Cristobal Manuel Arratia Martinez, Francesco Viola

In the present study, the response of model trailing vortices subjected to a harmonic forcing is studied. To this purpose, a globally stable non-parallel Batchelor vortex is considered as the baseflow. Direct numerical simulations (DNS) show that a large v ...

Cambridge University Press2016

Spatio-temporal stability of the Kármán vortex street and the effect of confinement

François Gallaire, Saviz Mowlavi, Cristobal Manuel Arratia Martinez

The instability of the Kármán vortex street is revisited under a spatio-temporal perspective that allows the taking into account of the advection of the vortices by the external flow. We analyse a simplified point vortex model and show through numerical si ...

Cambridge University Press2016

Pushing amplitude equations far from threshold: application to the supercritical Hopf bifurcation in the cylinder wake

François Gallaire, Philippe Meliga, Edouard Boujo, Vladislav Mantic Lugo, Cristobal Manuel Arratia Martinez

The purpose of this review article is to push amplitude equations as far as possible from threshold. We focus on the Stuart-Landau amplitude equation describing the supercritical Hopf bifurcation of the flow in the wake of a cylinder for critical Reynolds ...

Iop Publishing Ltd2016

A self-consistent model for the saturation dynamics of the vortex shedding around the mean flow in the unstable cylinder wake

François Gallaire, Vladislav Mantic Lugo, Cristobal Manuel Arratia Martinez

The supercritical instability leading to the Benard-von Karman vortex street in a cylinder wake is a well known example of supercritical Hopf bifurcation: the steady solution becomes linearly unstable and saturates into a periodic limit cycle. Nonetheless, ...

Amer Inst Physics2015

On the longitudinal optimal perturbations to inviscid plane shear flow: formal solution and asymptotic approximation

Cristobal Manuel Arratia Martinez

We study the longitudinal linear optimal perturbations (which maximize the energy gain up to a prescribed time T) to inviscid parallel shear flow, which present unbounded energy growth due to the lift-up mechanism. Using the phase invariance with respect t ...

Cambridge University Press2013