Recent experimental and theoretical efforts have revealed the existence of a fingering instability at the moving front of thin liquid films forced to spread under gravitational, rotational or surface shear stresses, as for example by using the Marangoni effect. We describe how the presence of a precursor film in front of the spreading macroscopic film, whether it is by prewetting the substrate ...

The hydrodynamic instability of one-dimensional flow of electrons in an ungated semiconductor driven by a voltage difference is studied. The governing transport and electrostatic equations are linearized about the steady flow, and the eigenspectrum of perturbations is calculated. The carrier flow is found to be unstable under certain circumstances through oscillations that manifest themselves a...

Results from time-dependent two-dimensional hydrodynamic simulations of the global heliosphere show that drag between the plasma ions and the interstellar neutrals, caused by charge-exchange collisions, causes the heliopause to be hydrodynamically unstable. Both ions and neutrals are treated as uids coupled by charge-exchange collisions. The neutral-ion drag proportional to the plasma density i...

The subsonic expansion of bubbles in a strongly first-order electroweak phase transition is a convenient scenario for electroweak baryogenesis. For most extensions of the Standard Model, stationary subsonic solutions (i.e., deflagrations) exist for the propagation of phase transition fronts. However, deflagrations are known to be hydrodynamically unstable for wall velocities below a certain cri...

Quantitatively unexplained stationary waves or ridges often encircle icicles. Such waves form when roughly 0.1-mm-thick layers of water flow down an icicle. These waves typically have a wavelength of about 1 cm, which is independent of external temperature, icicle thickness, and the volumetric rate of water flow. In this paper, we show that these waves cannot be obtained by a naive Mullins-Seke...

The evolution and relaxation of an initial shear flow subject to the Kelvin-Helmholtz instability are investigated via two-dimensional compressible hydrodynamic simulations and the calculus of variations. During the instability evolution the total kinetic energy remains almost constant, but the enstrophy decays rapidly by the selective dissipation with the artificial viscosity. The successive v...

Recently a fingering morphology, resembling the hydrodynamic Saffman-Taylor instability, was identified in the quasi-two-dimensional electrodeposition of copper. We present here measurements of the dispersion relation of the growing front. The instability is accompanied by gravity-driven convection rolls at the electrodes, which are examined using particle image velocimetry. While at the anode ...

A simplified model describing acoustically-generated parametric instability in a spherical chamber is developed for quasi-one-dimensional, low-Mach flames. We demonstrate how sound waves generated by a centrally-ignited, outwardly-propagating accelerating flamefront can be incorporated into a theory of self-similar flame acceleration in free space developed previously. Being reflected from the ...

A new method for the simulation of 2D viscoelastic flow is presented. Numerical stability is obtained by the logarithmic-conformation change of variable, and a fully-implicit pure-streamfunction flow formulation, without use of any artificial diffusion. As opposed to other simulation results, our calculations predict a hydrodynamic instability in the 4:1 contraction geometry at a Weissenberg nu...

Recent full hydrodynamic simulations of a sonoluminescing bubble interior have shown that the bubble content is compressed to a very dense state during the violent collapse. In this paper, we numerically studied the shape stability of a radially oscillating gas bubble by using Hilgenfeldt et al. theoretical model with corrections taking into account the gas density effect. Our results show that...