Reduced-order models for plane Couette flow are obtained by Galerkin projection of the Navier-Stokes equations onto leading controllability modes linearized system. Nonlinear dynamical systems so constructed, with various degrees truncation, numerically stable and reproduce statistics minimal turbulent at Reynolds numbers 500 1200 different choices modal bases. A closure model was not included ...

We study the microstructure formation and defects dynamics arising in liquid crystalline polymers (LCPs) in plane shear flow by a inetic–hydrodynamic coupled model. The kinetic model is an extension of the Doi theory with a non-local intermolecular potential, including ranslational diffusion and density variation. LCP molecules are ensured anchoring at the boundary by an additional boundary pot...

We report experimental discovery of a localized structure, which is of a new type for dissipative systems. It appears as a solitary vortex couple (”diwhirl”) in Couette flow with highly elastic polymer solutions. A unique property of the diwhirls is that they are stationary, in contrast to the usual localized wave structures in both Hamiltonian and dissipative systems which are stabilized by wa...

The hydromagnetic Couette flow of a viscous incompressible electrically conducting fluid bounded by two infinite parallel non-conducting plates in the presence of a uniform transverse magnetic field is studied on taking Hall currents into account. The relevant equations are solved analytically. The solution obtained shows that the inclusion of Hall currents gives some interesting results. It is...

Nonlinear equilibrium states characterized by strongly localized vortex pairs are calculated in the linearly stable parameter region of counterrotating Taylor-Couette flow. These subcritical states are rotating waves whose region of existence is consistent with the critical threshold for relaminarization observed in experiments. For sufficiently rapid outer cylinder rotation the solutions exten...

The flow in the gap between an inner rotating cylinder concentric with an outer stationary cylinder with an imposed pressure-driven axial flow was studied experimentally using particle image velocimetry ~PIV! in a meridional plane of the annulus. The radius ratio was h50.83 and the aspect ratio was G547. Velocity vector fields for nonwavy toroidal and helical vortices show the axial flow windin...