We simulate the evolution of an initially weak magnetic field in forced turbulence for a range of Prandtl numbers. The field grows exponentially with the Kulsrud-Anderson k 3/2 spectrum until the magnetic energy approaches the viscous-scale kinetic energy, where the magnetic forces then backreact on the velocity. Further growth proceeds more slowly until a saturated state is reached where the m...

The mixing efficiency Rf (more formally referred to as the flux Richardson number) is a widely used parameter that is intended to provide a measure of the amount of turbulent kinetic energy (TKE) that is irreversibly converted to background potential energy as a result of turbulent mixing in a stably stratified fluid. In this paper, three different definitions of the mixing efficiency that are ...

Characteristics of rotor blade tip clearance flow in axial compressors can significantly affect their performance and stable operation. It may also increase blade vibrations and cause detrimental noises. Therefore, this paper is contributed to investigate tip leakage flow in a low speed isolated axial compressor rotor blades row. Simulations are carried out on near-stall condition, which is val...

This paper presents a new parameterization for shear-driven, stratified, turbulent mixing that is pertinent to climate models, in particular the shear-driven mixing in overflows and the Equatorial Undercurrent. This parameterization satisfies a critical requirement for climate applications by being simple enough to be implemented implicitly and thereby allowing the parameterization to be used w...

The European program HORIZON2020 aims to have 20% of electricity produced by renewable sources. The building sector represents 40% of the European Union energy consumption. Reducing energy consumption in buildings is therefore a priority for energy efficiency. The present investigation explores the most adequate roof shapes compatible with the placement of different types of small wind energy g...

The present paper is primarily concerned with modeling complex turbulent wall-bounded flow in spray-painting processes by using a commercial CFD code. Computational results of turbulent channel flow with low Reynolds numbers are compared with DNS data in order to obtain the performance of turbulence models and near wall treatments. The realizable k-ε model with the nonequilibrium wall function ...

A physical-space version of the stretched-vortex subgrid-stress model is presented and applied to large-eddy simulations of incompressible flows. This version estimates the subgrid-kinetic energy required for evaluation of the subgrid-stress tensor using local second-order structure-function information of the resolved velocity field at separations of order the local cell size. A relation betwe...

The analysis of impeller shape performance was carried out with the SST (Shear-Stress Transport) model coupled with the streamline curvature turbulence model. This model combines the advantages from the κ−ε and κ−ω models, ensuring proper relation between turbulent stress and turbulent kinetic energy and allowing accurate and robust prediction of the impeller blade flow separation. The Multiple...

Transitions of tokamak confinement regimes from lowto highconfinement are studied on Alcator C-Mod [1] tokamak using gas-puff-imaging (GPI) with a focus on the interaction between the edge drift-turbulence and the local shear flow. Results show that the nonlinear turbulent kinetic energy transfer rate into the shear flow becomes comparable to the estimated value of the drift turbulence growth r...

This study assesses the sensitivity of numerical results of air flow modelling within an urban environment to the six different turbulence models applied in a specific case of a studied staggered cross-road. The principal parameters investigated in this comparison are position of centres of vortices within a street canyon, two components of the spatial velocity vector, turbulent kinetic energy,...