Publications related to Interaction of large scale flow structures with gyrokinetic turbulence

Laterally unconfined neutral or negative buoyancy inflow into a quiescent ambient over sloping bottom

This work studies the nearshore hydrodynamics of a shallow turbulent flow entering a laterally unconfined quiescent ambient with a sloping bottom boundary. Examples of such flow are neutrally buoyant ebb tidal jets and hyperpycnal river plumes entering ope ...

EPFL2023

Effects of the parallel flow shear on the ITG-driven turbulent transport in tokamak plasmas

Yann Camenen, Javier García Hernández, Samuele Mazzi

The impact of the parallel flow shear on the tokamak plasma stability and turbulent transport driven by the ion temperature gradient (ITG) modes is analyzed by means of local gyrokinetic numerical analyses. It is shown that the parallel flow shear increase ...

IOP Publishing Ltd2022

Transport barrier in 5D gyrokinetic flux-driven simulations

Two ways for producing a transport barrier through strong shear of the E x B poloidal flow have been investigated using GYSELA gyrokinetic simulations in a flux-driven regime. The first one uses an external poloidal momentum (i.e. vorticity) source that lo ...

IOP Publishing Ltd2022

Mixing and diffusion for rough shear flows

Maria Colombo, Klaus Martin Widmayer

This article addresses mixing and diffusion properties of passive scalars advected by rough (

C^\alpha

) shear flows. We show that in general, one cannot expect a rough shear flow to increase the rate of inviscid mixing to more than that of a smooth shear ...

2021

How eigenmode self-interaction affects zonal flows and convergence of tokamak core turbulence with toroidal system size

Stephan Brunner, Justin Richard Ball, Gabriele Merlo, Julien Stanislas Pierre Dominski, Ajay Chandrarajan Jayalekshmi

Self-interaction is the process by which a microinstability eigenmode that is extended along the direction parallel to the magnetic field interacts non-linearly with itself. This effect is particularly significant in gyrokinetic simulations accounting for ...

2020

Assessment of RANS turbulence models in urban environments: CFD simulation of airflow around idealized high-rise morphologies.

Fernando Porté Agel, Farshid Kardan, Olivier Baverel

This study presents the evaluation of Reynolds-averaged Navier Stokes (RANS) turbulence models, including the RNG k − ε, SST k − ω and more recently developed SST γ − Reθ models of flow past an idealized three-dimensional urban canopy. For validation purpo ...

Springer2017

Influence of the Coriolis force on the structure and evolution of wind turbine wakes

Fernando Porté Agel, Mahdi Abkar

In this study, large-eddy simulation combined with a turbine model is used to investigate the effect of vertical wind veer associated with the Coriolis force on the structure and evolution of wind turbine wakes. In order to isolate the Coriolis effect on t ...

Amer Physical Soc2016

Homoclinic snaking in plane Couette flow: bending, skewing and finite-size effects

Tobias Schneider

Invariant solutions of shear flows have recently been extended from spatially periodic solutions in minimal flow units to spatially localized solutions on extended domains. One set of spanwise-localized solutions of plane Couette flow exhibits homoclinic s ...

2016

Systematic errors of skin-friction measurements by oil-film interferometry

Peter Monkewitz, Jean-Daniel Rüedi

In recent years, the independent measurement of wall shear stress with oil-film or oil-drop interferometry has become a cornerstone of turbulent-boundary-layer research as many arguments depend critically on a precise knowledge of the skin friction tau(w)* ...

Cambridge University Press2015

Second-order sensitivity of parallel shear flows and optimal spanwise-periodic flow modifications

François Gallaire, Edouard Boujo, Andrea Fani

The question of optimal spanwise-periodic modification for the stabilisation of spanwise-invariant flows is addressed. A second-order sensitivity analysis is conducted for the linear temporal stability of parallel flows U-0 subject to small-amplitude spanw ...

Cambridge University Press2015

Interaction of large scale flow structures with gyrokinetic turbulence

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Laterally unconfined neutral or negative buoyancy inflow into a quiescent ambient over sloping bottom

Effects of the parallel flow shear on the ITG-driven turbulent transport in tokamak plasmas

Transport barrier in 5D gyrokinetic flux-driven simulations

Mixing and diffusion for rough shear flows

How eigenmode self-interaction affects zonal flows and convergence of tokamak core turbulence with toroidal system size

Assessment of RANS turbulence models in urban environments: CFD simulation of airflow around idealized high-rise morphologies.

Influence of the Coriolis force on the structure and evolution of wind turbine wakes

Homoclinic snaking in plane Couette flow: bending, skewing and finite-size effects

Systematic errors of skin-friction measurements by oil-film interferometry

Second-order sensitivity of parallel shear flows and optimal spanwise-periodic flow modifications

Laterally unconfined neutral or negative buoyancy inflow into a quiescent ambient over sloping bottom

Transport barrier in 5D gyrokinetic flux-driven simulations

Effects of the parallel flow shear on the ITG-driven turbulent transport in tokamak plasmas

Influence of the Coriolis force on the structure and evolution of wind turbine wakes

Second-order sensitivity of parallel shear flows and optimal spanwise-periodic flow modifications

Homoclinic snaking in plane Couette flow: bending, skewing and finite-size effects

Systematic errors of skin-friction measurements by oil-film interferometry

Mixing and diffusion for rough shear flows

How eigenmode self-interaction affects zonal flows and convergence of tokamak core turbulence with toroidal system size

Assessment of RANS turbulence models in urban environments: CFD simulation of airflow around idealized high-rise morphologies.