The mechanisms responsible for instabilities and a transition to turbulence in liquid metal duct flows of a fusion blanket are not understood very well, which limits predictive capabilities for heat and material transport in a blanket. In order to elucidate such mechanisms in quasi-two-dimensional (Q2D) magnetohydrodynamic flows with inflection points, an experimental and computational effort i...

We have performed 2.5D and 3D simulations of conical jets driven by the rotation of an ordered, large-scale magnetic field in a stratified atmosphere. The simulations cover about three orders of magnitude in distance to capture the centrifugal acceleration as well as the evolution past the Alfvén surface. We find that the jets develop kink instabilities, the characteristics of which depend on t...

2014 Recently we have developed a Couette viscosimeter for studying the shearing of colloidal crystals. We report here that with increasing shear rate the colloidal crystal melts (for 03C9crit) and above a critical shear rate, 03C9T0, Taylor instabilities develop. After stopping the shearing flow the suspension recrystallizes in a special texture which preserves the pattern of the Taylor rolls....

Simulations show that, when a phase-separated binary AB fluid is driven to flow past chemically patterned substrates in a microchannel, the fluid exhibits unique morphological instabilities. For the pattern studied, these instabilities give rise to the simultaneous, periodic formation of monodisperse droplets of A in B and B in A. The system bifurcates between time-independent behavior and diff...

This paper is the second part of the work on linear and nonlinear stability of buoyancy-driven coastal currents. Part 1, concerning a passive lower layer, was presented in the companion paper Gula & Zeitlin (J. Fluid Mech., vol. 659, 2010, p. 69). In this part, we use a fully baroclinic two-layer model, with active lower layer. We revisit the linear stability problem for coastal currents and st...

Four idealized direct numerical simulations are performed to examine the dynamics arising from the superposition of a monochromatic gravity wave (GW) and sinusoidal linear and rotary fine structure in the velocity field. These simulations are motivated by the ubiquity of such multiscale superpositions throughout the atmosphere. Three simulations explore the effects of linear fine structure alig...