We consider free convection in 2D and 3D horizontal cylindrical layers with the inner hot outer cold boundary at Ra (Rayleigh number) range (4?103 ÷ 4?105) ratio ? ? 1:20 of layer width to radius. Prandtl number was 0,71, fluid properties were taken for air 293 K. It shown that flow a can be divided into three regions. Stable symmetric convective rolls are formed layer’s upper part; regions tra...

The present paper provides a mathematical model for particle motion in viscous flow between rotating cylinders. Using an assumption that the mass fraction of particles in the flow is small, so the perturbations of the mean liquid flow due to the presence of particles is negligible, 3D liquid flow was simulated using an exact solution of the Navier-Stokes equations. Particle motion under action ...

A nonlinear stability analysis by Demay and looss [J. Mec. Theor. Appl. , special issue, p. 193 (1984)] of flow between concentric rotating cylinders (the Couette-Taylor system) predicted a transition from the basic flow to a state with ribbons, which are traveling waves in the azimuthal direction but standing waves in the axial direction. We have observed the transition to ribbons in laborator...

• Breaking the symmetry of material with sonic crystals to generate acoustic hooks. It has been demonstrated numerically that hooks obtained can be tunable. Potential applications in ultrasonic devices for manipulation or capture objects. In this paper we present a new way obtain tunable The breaking composition is used generation from Janus cylinders. This fact possible by using vary refractiv...

The proximity interference and the vortex dislocation are fundamental fluid dynamic features that determine a wake pattern of dual-step circular cylinders in side-by-side arrangement. Each cylinder consists two coaxial with different diameters. A complex modulation is expected due to an intrinsic interaction between shedding larger-diameter (LC) smaller-diameter (SC), cross-wake uniform flow. T...

We present a physical explanation of turbulent bursts in the flow between concentric, rotating cylinders (Couette-Taylor flow), based on fully resolved direct numerical calculations. The bursts are a temporal oscillation between a spatially laminar flow and turbulence, discovered experimentally by Hamill et al. The onset of turbulence is shown to be due to a linear instability of the spiral flo...