In the computation of turbulent flows via turbulence modeling, the treatment of the convective terms is a key issue. In the present work, we present a numerical technique for simulating two-dimensional incompressible turbulent flows. In particular, the performance of the high Reynolds κ-ε model and a new high-order upwind scheme (adaptative QUICKEST by Kaibara et al. (2005)) is assessed for 2D ...

Occurrence of laminar separation bubbles on solid walls of an elliptic cylinder has been simulated using a recently developed transitional model for boundary layer flows. Computational method is based on the solution of the Reynolds averaged Navier-Stokes (RANS) equations and the eddy-viscosity concept. Transitional model tries to simulate streamwise fluctuations, induced by freestream turbulen...

This work studies the momentum and energy transport mechanisms in the corner between a free surface and a solid wall. We perform large-eddy simulations of the incompressible fully developed turbulent flow in a square duct bounded above by a free-slip wall, for Reynolds numbers based on the mean friction velocity and the duct width equal to 360, 600 and 1000. The flow in the corner is strongly a...

the developing turbulent flow in an open channel is a complex three-dimensional flow influenced by the secondary currents and free surface effects and is, therefore, not amenable to analytical solution. this paper aims to study the impact of three key hydraulic parameters (relative roughness, the froude number and the reynolds number) on the establishment length using computational fluid dynami...

To simulate the effect of free st ream turbulence on turbulent spot formation, experiments were conducted on the interaction of localized three-dimensional disturbances with the harmonic waves in a laminar boundary layer on a flat plate. Experiments conducted in three-dimensional diverging flow (but zero pressure gradient) show, while individually the disturbances decay downstream, their intera...

The channel flow subjected to a wind stress at the free surface and an oscillating pressure gradient is investigated using large-eddy simulations. The orientation of the surface stress is parallel with the oscillating pressure gradient and a purely pulsating mean flow develops. The Reynolds number is typically Re!=10 and the Keulegan–Carpenter number—the ratio between the oscillation period and...

Abstract Steady plane turbulent free-surface flow over a slightly wavy bottom is considered for very large Reynolds numbers, small slopes, and Froude numbers close to the critical value 1. As in previous works, slope deviation from number are assumed be coupled such that turbulence modeling not required. The amplitudes of periodic elevations, however, half an order magnitude larger than case bu...

A hydraulic jump is a rapidly-varied open channel flow characterised by the sudden transition from a supercritical flow motion to a subcritical regime. The transition is associated with a rapid increase of water depth, a highly turbulent flow with macro-scale vortices, significant kinetic energy dissipation, a two-phase flow region and some strong turbulence interactions with the free surface l...