Several particle methods such as molecular dynamics, lattice gas, lattice Boltzmann and Bird will be compared to Navier–Stokes continuum hydro-dynamics as to their relative advantages and disadvantages. Particularly, the simulation of the " consistent " Boltzmann and its Enskog extension will be discussed. Evolution of the Rayleigh–Taylor unstable interface is known to be domi-nanted by bubble ...

After crossing an initial barrier to break the first base-pair (bp) in double-stranded DNA, the disruption of further bps is characterized by free energies up to a few k(B)T. Thermal motion within the DNA double strand therefore causes the opening of intermittent single-stranded denaturation zones, the DNA bubbles. The unzipping and zipping dynamics of bps at the two zipper forks of a bubble, w...

The interaction of a laser-induced cavitation bubble with an elastic boundary and its dependence on the distance between bubble and boundary are investigated experimentally. The elastic boundary consists of a transparent polyacrylamide (PAA) gel with 80% water concentration with elastic modulus E = 0.25 MPa. At this Evalue, the deformation and rebound of the boundary is very pronounced providin...

Acoustic properties of polymeric liquids are high sensitive to free gas traces in the form of fine bubbles. Their presence is typical for such liquids because of chemical reactions, small wettability of solid boundaries, trapping of air in technological operations, etc. Liquid temperature influences essentially its rheological properties, which may have an impact on the bubble pulsations and so...

We use time-resolved imaging to examine the lysis dynamics of non-adherent BAF-3 cells within a microfluidic channel produced by the delivery of single highly-focused 540 ps duration laser pulses at lambda = 532 nm. Time-resolved bright-field images reveal that the delivery of the pulsed laser microbeam results in the formation of a laser-induced plasma followed by shock wave emission and cavit...

Recent observations of growing and collapsing bubbles in flows over axisymmetric headforms have revealed the complexity of the 'micro-fluid-mechanics ' associated with these bubbles (van der Meulen & van Renesse 1989; Brianqon-Marjollet et al. 1990; Ceccio & Brennen 1991). Among the complex features observed were the bubble-tobubble and bubble-to-boundary-layer interactions which leads to the s...

Industrial bubble column reactor for Fischer-Tropsch (FT) synthesis includes complex hydrodynamic, chemical and thermal interaction of three material phases: population of bubbles of different sizes, liquid and catalyst particles suspended in liquid. To simulate FT bubble column, a Computational Fluid Dynamics model is described here. The model is based on Eulerian multifluid formulation and ac...

When water flows through hydraulic turbomachines, the local pressure can become low enough to vaporize the water and create vapor cavities. This phenomenon is called cavitation. When the cavities collapse, shock waves and liquid jets traveling through the inclusions can erode nearby solid surfaces. The collapse of cavitation bubbles has been extensively investigated in the case of a single bubb...

This paper compares two physical mechanisms for the collapse of a bubble near a rigid wall: a traveling shock-induced collapse and a Rayleigh-like collapse due to a uniform rise of the pressure around the bubble. A multi-material compressible flow solver capable of handling material interfaces under high pressures is used to investigate these two scenarios for different levels of the driving pr...

Single bubble sonoluminescence (SBSL) is the brief flash of light emitted from a single, stable, acoustically forced bubble. In experiments, the maximum pressure amplitude with which a bubble may be forced is limited by considerations of spherical stability. The traditional linear stability analysis predicts a threshold for SBSL at a much lower pressure amplitude than experimental observations....