A statistical mechanical phase transition to turbulence in a model shear flow

A Computational Study of Transition to Turbulence in Shear Flow

Turbulent transition in a truncated 1D model for shear flow

We present a reduced model for the transition to turbulence in shear flow that is simple enough to admit a thorough numerical investigation while allowing spatiotemporal dynamics that are substantially more complex than those allowed in previous modal truncations. Our model allows a comparison of the dynamics resulting from initial perturbations that are localised in the spanwise direction with...

Numerical Study of Single Phase/Two-Phase Models for Nanofluid Forced Convection and Pressure Drop in a Turbulence Pipe Flow

In this paper, the problem of turbulent forced convection flow of water- alumina nanofluid in a uniformly heated pipe has been thoroughly investigated. In numerical study, single and two-phase models have been used. In single-phase modeling of nanofluid, thermal and flow properties of nanofluid have been considered to be dependent on temperature and volume fraction. Effects of volume fraction a...

Parametric study of a viscoelastic RANS turbulence model in the fully developed channel flow

One of the newest of viscoelastic RANS turbulence models for drag reducing channel flow with polymer additives is studied in different flow and rheological properties. In this model, finitely extensible nonlinear elastic-Peterlin (FENE-P) constitutive model is used to describe the viscoelastic effect of polymer solution and turbulence model is developed in the k-ϵ-(ν^2 ) ̅-f framework. The geome...

A Two-dimensional Model of Shear-flow Transition

We explore a two-dimensional dynamical system modeling transition in shear flows to try to understand the nature of an ’edge’ state. The latter is an invariant set in phase space separating the basin of attraction B of the laminar state into two parts distinguished from one another by the nature of relaminarizing orbits. The model is parametrized by R, a stand-in for Reynolds number. The origin...