In this paper the study of the behavior of the fuel flow through the injector nozzle using CFD tools is presented. Large Eddy Simulation will be used to model the internal flow turbulence in a Diesel fuel injector with velocities over 500 m/s. More specifically, the influence of boundary conditions applied to the model will be studied. The article analyses the influence of the inlet boundary co...

Résumé : Les performances des Systèmes de Gestion de Bases de Données Orientés Objets (SGBDOO) restent un problème d’actualité, à la fois pour les concepteurs et pour les utilisateurs. L’approche la plus répandue pour évaluer ces performances est l’expérimentation, qui consiste à mesurer directement les performances d’un système existant. Or, la simulation aléatoire à événements discrets présen...

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We consider a prototypical problem: simulate velocity and pressure in a turbulent flow using large eddy simulation (LES) and then use the results to estimate the force the underlying turbulent flow exerts on an immersed body. For eddy viscosity-type LES models we develop the appropriate continuous sensitivity equation and show how it can improve the functional estimate by using the sensitivity ...

In this paper we present an alternative formalism for large-eddy simulation that avoids the problems arising from filtering the governing equations. In particular, we instead propose to filter solutions leading to the ability to directly model subgrid-scale primitive variables; i.e., model physics rather than statistics. We then demonstrate construction of subgrid-scale models of scalar quantit...

Srinivas Ramakrishnan∗ Lingxiao Zheng† Rajat Mittal‡ Department of Mechanical and Aerospace Engineering George Washington University, Washington, DC Fady Najjar§ Lawrence Livermore Laboratory, Livermore, California George V. Lauder¶ The Museum of Comparative Zoology, Harvard University, Cambridge, MA, USA and Tyson L. Hedrick‖ Department of Biology, University of North Carolina, Chapel Hill,NC-...

We consider a family of large-eddy simulation (LES) models with an arbitrarily high consistency error O(δ2N+2) for N = 1, 2, 3, . . . that are based on the van Cittert deconvolution procedure. This family of models has been proposed and tested for LES with success by Adams and Stolz in a series of papers, e.g., [Deconvolution methods for subgrid-scale approximation in largeeddy simulation, in M...