The external and independent control of plasma flow velocity shears parallel and perpendicular to magnetic field lines is realized using segmented collisionless-plasma sources. Electrostatic ion-cyclotron instabilities are observed to be suppressed by the perpendicular flow velocity shears, the suppression physics of which is found to be distinguished into two aspects. On the other hand, the pa...

The fluid flow between a pair of coaxial circular cylinders generated by the uniform rotation of the inner cylinder and an azimuthal pressure gradient is susceptible to both Taylor and Dean type instabilities. The flow can be characterised by two parameters: a measure of the relative magnitude of the rotation and pressure effects and a non-dimensional Taylor number. Neutral curves associated wi...

We determine both experimentally and numerically the onset of elastic flow instabilities in viscoelastic polymer solutions with different levels of shear thinning. Previous experiments realized in microfluidic serpentine channels using dilute polymeric solutions showed that the onset of elastic instabilities strongly depends on the channel curvature. The scaling dependence is well captured by t...

Complex fluids such as emulsions, colloidal gels, polymer or surfactant solutions are all characterized by the existence of a "microstructure" which may couple to an external flow on time scales that are easily probed in experiments. Such a coupling between flow and microstructure usually leads to instabilities under relatively weak shear flows that correspond to vanishingly small Reynolds numb...

In this work, we studied a pressure-driven flow of a magnetorheological suspension through a cylindrical tube in the presence of a non-uniform magnetic field perpendicular to the tube and varying along its axis. The flow was realized with the help of a commercial capillary rheometer in a controlled-velocity mode. Experimental pressure-flow rate curves exhibited a local minimum, and flow instabi...

Self-organization of dislocation structures, slip line and band patterning, and macroscopic plastic instabilities are typical manifestations, at different scales of observation, of nonlinear cooperative phenomena. This general aspect is discussed with emphasis on the relations between the dynamic properties of dislocations, their collective behavior, the local plastic properties of a material a...

Stable operation of both axial and radial compressors is constrained by the occurence of aerodynamic flow instabilities: rotating stall and surge. Developments in the understanding of the physics behind these instabilities and ideas of how t o stabilize the compressor system, have opened the door t o a new era in the field of compressor control. This study gives an overview of the current state...