Anisotropic Blistering Instability of Highly Ellipsoidal Shells

Ebrahimi, Hamid; Ajdari, Amin; Vella, Dominic; Boudaoud, Arezki; Vaziri, Ashkan

doi:10.1103/physrevlett.112.094302

Cited by 15 publications

(13 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, while close to threshold (i.e.δ = O(1)), previous ABAQUS simulations [7] confirm the τ dependence predicted by (17), the predicted evolution of m with increasingδ has not been observed. This shortcoming is consistent with recent work, which showed significant hurdles in numerically predicting the wrinkle number [31].…”

Section: Comparison Of Floating Films To Pressurized Shellsmentioning

confidence: 70%

Wrinkling reveals a new isometry of pressurized elastic shells

Vella

Ebrahimi

Vaziri

et al. 2015

EPL

View full text Add to dashboard Cite

We consider the point indentation of a pressurized, spherical elastic shell. Previously it was shown that such shells wrinkle once the indentation reaches a threshold value. Here, we study the behaviour of this system beyond the onset of instability. We show that rather than simply approaching the classical 'mirror-buckled' shape, the wrinkled shell approaches a new, universal shape that reflects a nontrivial type of isometry. For a given indentation depth, this "asymptotic isometry", which is only made possible by wrinkling, is reached in the doubly asymptotic limit of weak pressure and vanishing shell thickness.

show abstract

Section: Comparison Of Floating Films To Pressurized Shellsmentioning

confidence: 70%

Wrinkling reveals a new isometry of pressurized elastic shells

Vella

Ebrahimi

Vaziri

et al. 2015

EPL

View full text Add to dashboard Cite

show abstract

“…with κ the turbulent diffusivity of αm. Exploring the influence of other potentially important contributions to the helicity flux (Vishniac & Cho 2001;Sur et al 2007;Vishniac 2012;Vishniac & Shapovalov 2014;Ebrahimi & Bhattacharjee 2014) is left for future work. We do, however, compare our results with results using the simple algebraic α-quenching formalism,…”

Section: Mean-field Dynamo Theorymentioning

confidence: 99%

An analytical dynamo solution for large-scale magnetic fields of galaxies

Chamandy

2016

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

We present an effectively global analytical asymptotic galactic dynamo solution for the regular magnetic field of an axisymmetric thin disc in the saturated state. This solution is constructed by combining two well-known types of local galactic dynamo solution, parameterized by the disc radius. Namely, the critical (zero growth) solution obtained by treating the dynamo equation as a perturbed diffusion equation is normalized using a non-linear solution that makes use of the 'no-z' approximation and the dynamical αquenching non-linearity. This overall solution is found to be reasonably accurate when compared with detailed numerical solutions. It is thus potentially useful as a tool for predicting observational signatures of magnetic fields of galaxies. In particular, such solutions could be painted onto galaxies in cosmological simulations to enable the construction of synthetic polarized synchrotron and Faraday rotation measure (RM) datasets. Further, we explore the properties of our numerical solutions, and their dependence on certain parameter values. We illustrate and assess the degree to which numerical solutions based on various levels of approximation, common in the dynamo literature, agree with one another.

show abstract

“…Below, we discuss some terms in Equation (6) that have been identified and found to be significant in numerical simulations and we leave the investigation of the remaining terms in Equations (5) and (6) for future studies aided by numerical simulations. The relative contribution from each term in Equation (6) to the small-scale magnetic helicity transport equation has been explored recently through numerical simulations (Ebrahimi & Bhattacharjee 2014;Vishniac & Shapovalov 2014). Vishniac & Shapovalov (2014) found that the advective flux, (a · b)U, is the most dominant term in Equation (6), contributing about 80% of the helicity flux.…”

Section: Nonlinear Mean-field Dynamo and Magnetic Helicity Dynamicsmentioning

confidence: 99%

A Global Galactic Dynamo With a Corona Constrained by Relative Helicity

Prasad¹,

Mangalam

2016

ApJ

View full text Add to dashboard Cite

We present a model for a global axisymmetric turbulent dynamo operating in a galaxy with a corona that treats the parameters of turbulence driven by supernovae and by magneto-rotational instability under a common formalism. The nonlinear quenching of the dynamo is alleviated by the inclusion of small-scale advective and diffusive magnetic helicity fluxes, which allow the gauge-invariant magnetic helicity to be transferred outside the disk and consequently to build up a corona during the course of dynamo action. The time-dependent dynamo equations are expressed in a separable form and solved through an eigenvector expansion constructed using the steady-state solutions of the dynamo equation. The parametric evolution of the dynamo solution allows us to estimate the final structure of the global magnetic field and the saturated value of the turbulence parameter α m , even before solving the dynamical equations for evolution of magnetic fields in the disk and the corona, along with α-quenching. We then solve these equations simultaneously to study the saturation of the large-scale magnetic field, its dependence on the small-scale magnetic helicity fluxes, and the corresponding evolution of the force-free field in the corona. The quadrupolar large-scale magnetic field in the disk is found to reach equipartition strength within a timescale of 1 Gyr. The large-scale magnetic field in the corona obtained is much weaker than the field inside the disk and has only a weak impact on the dynamo operation.

show abstract

Anisotropic Blistering Instability of Highly Ellipsoidal Shells

Cited by 15 publications

References 24 publications

Wrinkling reveals a new isometry of pressurized elastic shells

Wrinkling reveals a new isometry of pressurized elastic shells

An analytical dynamo solution for large-scale magnetic fields of galaxies

A Global Galactic Dynamo With a Corona Constrained by Relative Helicity

Contact Info

Product

Resources

About