A numerical study based on the Eulerian-Lagrangian formulation is performed for dispersed phase motion in a turbulent flow. The effect of spatial filtering, commonly employed in large-eddy simulations, and the role of the subgrid scale turbulence on the statistics of heavy particles, including preferential concentration, are studied through a priori analysis of DNS of particle-laden forced isot...

The long-term goal of this research is to refine and extend simple (existing) model parameterizations for turbulent diapycnal mixing for use in large scale numerical ocean models where such processes occur at the subgrid-scale. From a scientific view point, the goal is to obtain new insights into the dynamics of stratified turbulence that will translate into simple effective parameterizations f...

Modeling the primary atomization of turbulent liquid jets and sheets still remains an unsolved problem. Considering numerical grid resolutions typical for Large Eddy Simulations, the large scale liquid structures during primary breakup are well resolved, whereas all small scale structures are unresolved and thus require modeling. To help in the derivation of such subgrid models, DNS of the turb...

Although the general characteristics of DNAPL flow and transport in the subsurface are reasonably well understood, it is often difficult and expensive to pinpoint sources of DNAPL contamination. Inversion techniques to improve site characterization rely on a forward model of multiphase flow. Ideally the forward model would be very fast, so that many realizations can be carried out in order to q...

The lattice Boltzmann method has become a widely used tool for the numerical simulation of fluid flows and in particular of turbulent flows. In this frame the inclusion of subgrid scale closures is of crucial importance and is not completely understood from the theoretical point of view. Here, we propose a consistent way of introducing subgrid closures in the BGK Boltzmann equation for large ed...

We present a two-scale theoretical framework for approximating the solution of a second order elliptic problem. The elliptic coefficient is assumed to vary on a scale that can be resolved on a fine numerical grid, but limits on computational power require that computations be performed on a coarse grid. We consider the elliptic problem in mixed variational form over W × V ⊂ L2 × H(div). We base...

The objective of this paper is to study the feasibility of large eddy simulations of a liquid fuel injection in combustion chambers. To do so, a priori analyses of direct numerical simulations are carried out. A complete liquid jet atomization, from the injector down to the end of the liquid core, is simulated thanks to the coupling of both level-set and VOF formulations. To avoid the apparitio...

Stochastic coherent adaptive large eddy simulation SCALES is an extension of the large eddy simulation approach in which a wavelet filter-based dynamic grid adaptation strategy is employed to solve for the most “energetic” coherent structures in a turbulent field while modeling the effect of the less energetic background flow. In order to take full advantage of the ability of the method in simu...

A premixed turbulent combustion Direct Numerical Simulation (DNS) database of a swirl burner is analyzed from three angles: estimation of the three-dimensional flame surface from two-dimensional fields; modeling of subgrid source and flux terms entering the balance equation for the reaction progress variable in Large Eddy Simulation (LES); and modeling of the subgrid-scale scalar variance in LE...