Michel Deville - Academia.edu (original) (raw)
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Pakistan Institute of engineering and applied science (PIEAS)
Institute of Archaeology and Ethnology Polish Academy of Sciences
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Papers by Michel Deville
Physics of Fluids, 2001
Traditional large-eddy simulation ͑LES͒ provides good results on standard benchmark turbulent flo... more Traditional large-eddy simulation ͑LES͒ provides good results on standard benchmark turbulent flows, but engineering applications involving more complex geometries are restricted. This is mainly due to the physical hypotheses of homogeneity, isotropy, or local equilibrium of the subgrid-scale ͑SGS͒ models, which are questionable in more realistic configurations. It appears essential to qualify the built-in filters of LES models before performing coarse mesh/high Reynolds number computations. A study of the Smagorinsky and the Schumann models with a mesh-independent filtering length larger than the mesh size is presented in this paper. The forms of the associated built-in filters are identified, and a control of the filter length through the SGS model is performed. Finally an asymptotic behavior of the filter is found to be independent of the spatial scheme for large filter length. This work is partly an assessment of previous theoretical studies on LES filters and kinetic energy spectra.
Physical review. E, Statistical, nonlinear, and soft matter physics, 2008
Various ways of implementing boundary conditions for the numerical solution of the Navier-Stokes ... more Various ways of implementing boundary conditions for the numerical solution of the Navier-Stokes equations by a lattice Boltzmann method are discussed. Five commonly adopted approaches are reviewed, analyzed, and compared, including local and nonlocal methods. The discussion is restricted to velocity Dirichlet boundary conditions, and to straight on-lattice boundaries which are aligned with the horizontal and vertical lattice directions. The boundary conditions are first inspected analytically by applying systematically the results of a multiscale analysis to boundary nodes. This procedure makes it possible to compare boundary conditions on an equal footing, although they were originally derived from very different principles. It is concluded that all five boundary conditions exhibit second-order accuracy, consistent with the accuracy of the lattice Boltzmann method. The five methods are then compared numerically for accuracy and stability through benchmarks of two-dimensional and t...
Physics of Fluids, 2001
Traditional large-eddy simulation ͑LES͒ provides good results on standard benchmark turbulent flo... more Traditional large-eddy simulation ͑LES͒ provides good results on standard benchmark turbulent flows, but engineering applications involving more complex geometries are restricted. This is mainly due to the physical hypotheses of homogeneity, isotropy, or local equilibrium of the subgrid-scale ͑SGS͒ models, which are questionable in more realistic configurations. It appears essential to qualify the built-in filters of LES models before performing coarse mesh/high Reynolds number computations. A study of the Smagorinsky and the Schumann models with a mesh-independent filtering length larger than the mesh size is presented in this paper. The forms of the associated built-in filters are identified, and a control of the filter length through the SGS model is performed. Finally an asymptotic behavior of the filter is found to be independent of the spatial scheme for large filter length. This work is partly an assessment of previous theoretical studies on LES filters and kinetic energy spectra.
Physical review. E, Statistical, nonlinear, and soft matter physics, 2008
Various ways of implementing boundary conditions for the numerical solution of the Navier-Stokes ... more Various ways of implementing boundary conditions for the numerical solution of the Navier-Stokes equations by a lattice Boltzmann method are discussed. Five commonly adopted approaches are reviewed, analyzed, and compared, including local and nonlocal methods. The discussion is restricted to velocity Dirichlet boundary conditions, and to straight on-lattice boundaries which are aligned with the horizontal and vertical lattice directions. The boundary conditions are first inspected analytically by applying systematically the results of a multiscale analysis to boundary nodes. This procedure makes it possible to compare boundary conditions on an equal footing, although they were originally derived from very different principles. It is concluded that all five boundary conditions exhibit second-order accuracy, consistent with the accuracy of the lattice Boltzmann method. The five methods are then compared numerically for accuracy and stability through benchmarks of two-dimensional and t...