Nonlinear hydrodynamic instability and turbulence in pulsatile flow

Nonlinear hydrodynamic phenomena in Stokes flow regime

We investigate nonlinear phenomena in dispersed two-phase systems under creeping-flow conditions. We consider nonlinear evolution of a single deformed drop and collective dynamics of arrays of hydrodynamically coupled particles. To explore physical mechanisms of system instabilities, chaotic drop evolution, and structural transitions in particle arrays we use simple models, such as small-deform...

Nonlinear stability and instability in collisionless trapped electron mode turbulence

A two-field model for collisionless trapped electron mode turbulence has both finite amplitude-induced stability and instability, depending on wave number. Effects usually identified with nonlinear plasma instability ~self-trapping, kinetics, 3D mode structure, magnetic shear! are absent. Nonlinear stability and instability reside in E3B advection of density. It drives modes of a purely damped ...

Quantum turbulence and nonlinear instability in quantum fluids

We will discuss quantum turbulence and related nonlinear instability. In quantum condensed systems appear quantized vortices through the order parameters (macroscopic wave functions), and turbulence consisting of quantized vortices is called quantum turbulence (QT). Quantized vortices and QT were discovered in superfluid helium in the 1950’s, while they have become one of the most important the...

Characterization of Flow- Magnetic Field Interactions in Magneto-Hydrodynamic Turbulence

We examine the complex nonlinear flow-magnetic field dynamics in magnetohydrodynamic (MHD) turbulence. Using direct numerical simulations (DNS), we investigate the dynamical interactions subject to the influence of a uniform applied background magnetic field. The initial magnetic and kinetic Reynolds numbers (based on Taylor microscale) are 45 and there are no initial magnetic field fluctuation...

On the nonlinear theory of hydrodynamic instability in flames