Hydrodynamic instability of chemical waves

Spontaneous generation of spiral waves by a hydrodynamic instability

The coiling of a thin filament of viscous fluid falling onto a surface is a common and easily reproducible hydrodynamic instability. Here we report for the first time that this instability can generate regular spiral patterns, in which air bubbles are trapped in the coil and then advected horizontally by the fluid spreading on the surface. We present a simple model that explains how these beaut...

Nonlinear front evolution of hydrodynamic chemical waves in vertical cylinders

Energy Gradient Theory of Hydrodynamic Instability

A new universal theory for flow instability and turbulent transition is proposed in this study. Flow instability and turbulence transition have been challenging subjects for fluid dynamics for a century. The critical condition of turbulent transition from theory and experiments differs largely from each other for Poiseuille flows. This enigma has not been clarified so far owing to the difficult...

Some peculiar features of hydrodynamic instability development.

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...

Generic Hydrodynamic Instability of Curl Eigenfields

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.