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A two-field Hamiltonian gyrofluid model for kinetic Alfv\'en waves retaining ion finite Larmor radius corrections, parallel magnetic field fluctuations and electron inertia, is used to study turbulent cascades from the MHD to the sub-ion…

Plasma Physics · Physics 2019-05-29 T. Passot , P. L. Sulem

We observe the emergence of strong vertical drafts in direct numerical simulations of the Boussinesq equations in a range of parameters of geophysical interest. These structures, which appear intermittently in space and time, generate…

We present results from an asymptotic magnetohydrodynamic model that is suited for studying the rapidly rotating, low viscosity regime typical of the electrically conducting fluid interiors of planets and stars. We show that the presence of…

Geophysics · Physics 2019-04-17 Stefano Maffei , Michael A. Calkins , Keith Julien , Philippe D. Marti

The presence of a dispersed phase substantially modifies small-scale turbulence. However, there has not been a comprehensive mechanistically-based understanding to predict turbulence modulation. Based on the energy flux balance, we propose…

Fluid Dynamics · Physics 2023-11-23 S. Balachandar , C. Peng , L. -P. Wang

The new mode of instability found by Tunney et al. is studied with viscous stability theory in this article. When the high-speed boundary layer is subject to certain values of favorable pressure gradient and wall heating, a new mode becomes…

Fluid Dynamics · Physics 2020-05-14 Jie Ren , Youcheng Xi , Song Fu

Non-Newtonian fluids have a viscosity that varies with applied stress. Elastoviscoplastic fluids, the elastic, viscous and plastic properties of which are interconnected in a non-trivial way, belong to this category. We have performed…

Fluid Dynamics · Physics 2023-08-02 Mohamed S. Abdelgawad , Ianto Cannon , Marco E. Rosti

We prove that all Galerkin truncations of the 2d stochastic Navier-Stokes equations in vorticity form on any rectangular torus subjected to hypoelliptic, additive stochastic forcing are chaotic at sufficiently small viscosity, provided the…

Probability · Mathematics 2022-08-04 Jacob Bedrossian , Sam Punshon-Smith

We introduce a modification of the Navier-Stokes equation that has the remarkable property of possessing an infinite number of conserved quantities in the inviscid limit. This new equation is studied numerically and turbulence properties…

Fluid Dynamics · Physics 2015-06-05 Tobias Grafke , Rainer Grauer , Thomas C. Sideris

The shear misfit model for the highly viscous flow is based upon a theoretical prediction for its terminal stage in terms of irreversible Eshelby relaxations in the five-dimensional shear space. The model is shown to predict a small…

Disordered Systems and Neural Networks · Physics 2022-08-25 U. Buchenau

The non-linear hydrodynamic stability of thin, compressible, Keplerian disks is studied on the large two-dimensional compressible scale, using a high-order accuracy spectral method. We show that purely hydrodynamic perturbations, while…

Astrophysics · Physics 2009-10-31 Patrick Godon , Mario Livio

It has been hypothesized that liquid polyamorphism, the existence of multiple amorphous states in a single component substance, may be caused by molecular or supramolecular interconversion. A simple microscopic model [Caupin and Anisimov,…

Soft Condensed Matter · Physics 2023-09-19 Thomas J. Longo , Sergey V. Buldyrev , Mikhail A. Anisimov , Frédéric Caupin

The role of turbulence in a spherically symmetric accreting system has been studied on very large spatial scales of the system. This is also a highly subsonic flow region and here the accreting fluid has been treated as nearly…

Astrophysics · Physics 2009-11-10 Arnab K. Ray , J. K. Bhattacharjee

An efficient time-stepping algorithm is proposed based on operator-splitting and the space-time discontinuous Galerkin finite element method for problems in the non-classical theory of thermoelasticity. The non-classical theory incorporates…

Numerical Analysis · Mathematics 2015-05-05 Mebratu F. Wakeni , B. D. Reddy , A. T. McBride

Warped astrophysical discs are usually treated as laminar viscous flows, which have anomalous properties when the disc is nearly Keplerian and the viscosity is small: fast horizontal shearing motions and large torques are generated, which…

Solar and Stellar Astrophysics · Physics 2015-06-15 Gordon I. Ogilvie , Henrik N. Latter

In the context of incompressible fluids, the observation that turbulent singular structures fail to be space filling is known as ``intermittency'' and it has strong experimental foundations. Consequently, as first pointed out by Landau,…

Analysis of PDEs · Mathematics 2023-12-19 Luigi De Rosa , Philip Isett

We consider a low-dimensional model of convection in a horizontally magnetized layer of a viscous fluid heated from below. We analyze in detail the stability of hydromagnetic convection for a wide range of two control parameters. Namely,…

Chaotic Dynamics · Physics 2014-03-26 Wieslaw M. Macek , Marek Strumik

I review the capabilities of H$\alpha$ observations to constrain some aspects of the current models of the interstellar medium. In particular, it is shown that turbulence is a necessary ingredient of any viable model, since most of the…

Astrophysics · Physics 2015-06-24 Andrea Ferrara

Turbulence has strong and seemingly random fluctuations. Assessing its repeatability is key to predicting flows in technology and nature, much of which decay as viscosity dissipates energy. Much has been done to this end since the work of…

Fluid Dynamics · Physics 2026-05-11 Noé Clavier , Eberhard Bodenschatz , Florencia Falkinhoff

Visual manifestations of intermittency in computations of three dimensional Navier-Stokes fluid turbulence appear as the low-dimensional or `thin' filamentary sets on which vorticity and strain accumulate as energy cascades down to small…

Chaotic Dynamics · Physics 2020-12-02 John D. Gibbon

We demonstrate that the correlations observed in conditioned multiplier distributions of the energy dissipation in fully developed turbulence can be understood as an unavoidable artefact of the observation procedure. Taking the latter into…

chao-dyn · Physics 2009-10-31 Bruno Jouault , Peter Lipa , Martin Greiner