The non-linear thin-shell instability (NTSI) may explain some of the turbulent hydrodynamic structures that are observed close to the collision boundary of energetic astrophysical outflows. It develops in non-planar shells that are bounded on either side by a hydrodynamic shock, provided that the amplitude of the seed oscillations is sufficiently large. The hydrodynamic NTSI has amicroscopic co...

Summary It is shown how the flow from pumping cement through an open-ended pipe very quickly changes direction and flows upward. This rapid change in indicates that a diverter tool, which leads slurry perpendicularly out of closed-ended pipe, does not have any function. The placement balanced plug feasible. However, high-density fluid above lighter stable. phenomenon known as Rayleigh-Taylor in...

We discuss the results of experiments that illustrate some features of a turbulent mixing zone (TMZ) structure at a gas-liquid interface (Rayleigh-Taylor instability) and at a gas-gas interface accelerated by shock waves (Richtmyer-Meshkov instability). The important feature is the existence of a heavier substance concentration (density) jump at the interface between the heavy medium and the TM...

2014 We study the hydrodynamic instability thresholds of a homeotropic nematic subjected to an elliptical shear. We analyse the role of the changes in the symmetry caused by the variation of the ellipticity of the shear around the degenerate circular polarization. Tome 43 No 7 JUILLET 1982 LE JOURNAL DE PHYSIQUE J. Physique 43 (1982) 985-989 JUILLET 1982, Classification Physics Abstracts 61.30E...

We prove that for generic geometry, the curl-eigenfield solutions to the steady Euler equations on R 3 /Z 3 are all hydrodynamically unstable (linear, L norm). The proof involves amarriage of contact topological methods with the instability criterion of Friedlander-Vishik. An application of contact homology is the crucial step.

The design and reliable operation of a two-phase micro-channel heat sink require a fundamental understanding of the complex transport phenomena associated with convective boiling in small, parallel coolant passages. This understanding is the primary goal of this paper. This goal is realized by exploring the following aspects of boiling in microchannels: hydrodynamic instability, two-phase flow ...

The effect of the magnetic field on the Jeans instability of self-gravitating strongly coupled dusty plasma is investigated. The medium consists of extremely massive, negatively charged strongly correlated dust grains and weakly correlated Boltzmann distributed electrons and ions. The basic equations of the problem are constructed using generalized hydrodynamic model. In deriving dispersion rel...

Rapid angular momentum transport in accretion disks has been a longstanding astrophysical puzzle. Molecular viscosity is inadequate to explain observationally inferred accretion rates. Since Keplerian flow profiles are linearly stable in hydrodynamics, there exist only two viable mechanisms for the required turbulence: nonlinear hydrodynamic instability or magnetohydrodynamic instability. The l...

We report on the experimental observation of the instability of a plasma shell, which formed during the expansion of a laser-ablated plasma into a rarefied ambient medium. By means of a proton radiography technique, the evolution of the instability is temporally and spatially resolved on a timescale much shorter than the hydrodynamic one. The density of the thin shell exceeds that of the surrou...