A fractional subgrid-scale model for turbulent flows: Theoretical formulation and a priori study

On Implicit Subgrid Scale Modeling for Turbulent Flows

Large Eddy Simulation (LES) is an effective intermediate approach between DNS and RANS, capable of simulating flow features which cannot be handled with RANS such as significant flow unsteadiness and strong vortex-acoustic couplings, and providing higher accuracy than RANS at reasonable cost but still typically an order of magnitude more expensive. Desirable modeling choices involve selecting a...

Subgrid Scale Model for Finite Difference Simulations of Turbulent Flows in Plane Channels and Annuli

High Reynolds number turbulent flows of incompressible fluids in plane channels and annuli are simulated using a finite difference procedure which integrates the NavierStokes equations in time and in three-dimensional space. This paper describes the finite difference procedure and the subgrid scale (SGS) motion model. The model differs from earlier ones in the following points. The finite diffe...

A Discrete Dynamical System Subgrid-Scale Model of Turbulent Convection

Subgrid-scale model for the temperature fluctuations in reacting hypersonic turbulent flows

A direct numerical simulation ~DNS! database is used to develop a model of subgrid-scale temperature fluctuations for use in large-eddy simulations of turbulent, reacting hypersonic flows. The proposed model uses a probability density representation of the temperature fluctuations. The DNS database reveals a physically consistent relation between the resolved-scale flow conditions that may be u...

Small scale localization in turbulent flows. A priori tests applied to a possible Large Eddy Simulation of compressible turbulent flows

Amethod for the localization of small scales in turbulent velocity fields is proposed. The method is based on the definition of a function f of the velocity and vorticity fields that reproduces a normalized form of the twisting-stretching term of the Helmholtz equation. By means of this method the equations of motion can be selectively filtered in regions that are rich in small scale motions. T...