To obtain the turbulent velocity profiles in Couette and Poiseuille flows between parallel walls, we use statistical mechanics of point vortices. Our theory does not contain phenomenological constants. The only parameter taken from experiments is the total kinetic energy of the flow. We solve numerically the equation for averaged flow and show that the theoretical predictions are in good agreem...

We present the complete unfolding of streamwise localisation in a paradigm of extended shear flows, namely, two-dimensional plane-Poiseuille flow. Exact solutions of the Navier-Stokes equations are computed numerically and tracked in the streamwise wavenumber Reynolds number parameter space to identify and describe the fundamental mechanism behind streamwise localisation, a ubiquitous feature o...

An equation previously proposed to describe the evolution of vortex line density in rotating counterflow turbulent tangles in superfluid helium is generalized to incorporate nonvanishing barycentric velocity and velocity gradients. Our generalization is compared with an analogous approach proposed by Lipniacki, and with experimental results by Swanson et al. in rotating counterflow, and it is u...

Abstract. In the present work the application of hierarchical grid refinement for the Lattice-Boltzmann Method (LBM) to simulate turbulent flows has been investigated. A transformation and interpolation scheme has been developed based on a volumetric approach, independent of a specific collision model and therefore, generally applicable to all variants of the LBM. Besides a short review of the ...

Diffusion–convection impedance for a micro-band electrode placed in Poiseuille flow was studied experimentally under microfluidic conditions. Electrochemical spectroscopy (EIS) experiments performed with fast electrochemical system show perfect agreement previously published quantitative analytical expression the low frequency domain.

a finite volume-lattice boltzmann algorithm is applied to study skin friction behaviour in different channel flows. for this purpose, cell centred scheme is adapted to discretize the boltzmann equation and consistent boundary conditions are also addressed, which resulted in a wider domain of stability. a simulation of flow in a two dimensional channels with different geometries are carried out....

Motivated by the recent discovery of a dispersive-to-nondispersive transition for linear waves in shear flows, we accurately explored wavenumber-Reynolds number parameter map plane Poiseuille flow limit least-damped waves. We have discovered existence regions where dispersion and propagation features vary significantly from their surroundings. These are nested dispersive, low-wavenumber part ma...

The energy gradient theory has been proposed with the aim of better understanding the mechanism of flow transition from laminar flow to turbulent flow. In this theory, it is suggested that the transition to turbulence depends on the relative magnitudes of the energy gradient amplifying the disturbance and the viscous friction damping that disturbance. For a given flow geometry and fluid propert...

A two dimensional numerical simulation has been performed for incompressible and compressible fluid flow through microchannels in slip flow regime. The Navier-Stokes equations have been solved in conjunction with Maxwell slip conditions for modeling flow field associated with slip flow regime. The wall roughness is simulated with triangular microelements distributed on wall surfaces to study th...