Precursor of Transition to Turbulence in an Oscillatory Flow.

On the Transition to Turbulence of Oscillatory Flow of Liquid Helium-4

Oscillating solid bodies have frequently been used for studying the properties of normal and superfluid helium. In particular, the transition from laminar flow to turbulence has attracted much interest recently. The purpose of this note is to review several central features of this transition in oscillatory flow, which have been inaccurately formulated in some recent work. PACS numbers: 47.27.C...

Transition to turbulence in particulate pipe flow.

We investigate experimentally the influence of suspended particles on the transition to turbulence. The particles are monodisperse and neutrally buoyant with the liquid. The role of the particles on the transition depends upon both the pipe to particle diameter ratios and the concentration. For large pipe-to-particle diameter ratios the transition is delayed while it is lowered for small ratios...

Precursor of transition to turbulence: spatiotemporal wave front.

To understand transition to turbulence via 3D disturbance growth, we report here results obtained from the solution of Navier-Stokes equation (NSE) to reproduce experimental results obtained by minimizing background disturbances and imposing deterministic excitation inside the shear layer. A similar approach was adopted in Sengupta and Bhaumik [Phys. Rev. Lett. 107, 154501 (2011)], where a rout...

Turbulence Transition in Pipe Flow

Pipe flow is a prominent example among the shear flows that undergo transition to turbulence without mediation by a linear instability of the laminar profile. Experiments on pipe flow, as well as plane Couette and plane Poiseuille flow, show that triggering turbulence depends sensitively on initial conditions, that between the laminar and the turbulent states there exists no intermediate state ...

A Computational Study of Transition to Turbulence in Shear Flow