Ara es mostren els items 21-40 de 80

    • DNS and LES on unstructured grids: playing with matrices to preserve symmetries using a minimal set of algebraic kernels 

      Trias Miquel, Francesc Xavier; Álvarez Farré, Xavier; Alsalti Baldellou, Àdel; Gorobets, Andrei; Oliva Llena, Asensio (Scipedia, 2022)
      Text en actes de congrés
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      The essence of turbulence are the smallest scales of motion. They result from asubtle balance between two differential operators differing in symmetry: The convective operator is skew-symmetric, whereas the diffusive is ...
    • DNS and regularization modeling of a turbulent differentially heated cavity of aspect ratio 5 

      Trias Miquel, Francesc Xavier; Gorobets, Andrei; Oliva Llena, Asensio; Pérez Segarra, Carlos David (2013-01-15)
      Article
      Accés obert
      This work is devoted to the study of turbulent natural convection flows in differentially heated cavities. The adopted configuration corresponds to an airfilled (Pr = 0.7) cavity of aspect ratio 5 and Rayleigh number Ra ...
    • DNS of turbulent natural convection flows on the MareNostrum supercomputer 

      Trias Miquel, Francesc Xavier; Gorobets, Andrei; Soria Guerrero, Manel; Oliva Llena, Asensio (2009)
      Article
      Accés restringit per política de l'editorial
      A code for the direct numerical simulation (DNS) of incompressible turbulent flows that provides a fairly good scalability for a wide range of computer architectures has been developed. The spatial discretization of the ...
    • DNS/LES using a minimal set of algebraic Kernels: challenges and opportunities 

      Trias Miquel, Francesc Xavier; Álvarez Farré, Xavier; Alsalti Baldellou, Àdel; Gorobets, Andrei; Oliva Llena, Asensio (Parallel Computational Fluid Dynamics (ParCFD), 2022)
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      In the last decades, CFD has become a standard design tool in many fields such as automotive, aeronautical and wind power industries. The driven force behind this is the development of numerical techniques in conjunction ...
    • Effect of collisions on the particle behavior in a turbulent square duct flow 

      Zhang, Hao; Trias Miquel, Francesc Xavier; Gorobets, Andrei; Oliva Llena, Asensio; Yang, Dongmin; Tan, Yuanqiang; Sheng, Yong (2015-01-01)
      Article
      Accés restringit per política de l'editorial
      The effect of collisions on the particle behavior in a fully developed turbulent flow in a straight square duct at Re-r = 300 is numerically investigated. The hydrodynamic modeling of the fluid phase is based on direct ...
    • Efficiency of large-scale CFD simulations on modern supercomputers using thousands of CPUS and hybrid MPI+OPENMP parallelization 

      Gorobets, Andrei; Borrell Pol, Ricard; Trias Miquel, Francesc Xavier; Kozubskaya, T.K.; Oliva Llena, Asensio (2010)
      Comunicació de congrés
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      This work represents an experience in using the hybrid parallel model to perform large-scale DNS. Advantages of the hybrid approach compared to the MPI-only approach are presented and discussed. The use of OpenMP in addition ...
    • Efficient CFD code implementation for the ARM-based Mont-Blanc architecture 

      Oyarzun Altamirano, Guillermo; Borrell Pol, Ricard; Gorobets, Andrei; Mantovani, Filippo; Oliva Llena, Asensio (Elsevier, 2017-09-20)
      Article
      Accés obert
      Since 2011, the European project Mont-Blanc has been focused on enabling ARM-based technology for HPC, developing both hardware platforms and system software. The latest Mont-Blanc prototypes use system-on-chip (SoC) devices ...
    • Efficient CFD code implementation for the ARM-based Mont-Blanc architecture 

      Oyarzun Altamirano, Guillermo; Borrell Pol, Ricard; Gorobets, Andrei; Mantovani, Filippo; Oliva Llena, Asensio (Elsevier, 2018-02)
      Article
      Accés obert
      Since 2011, the European project Mont-Blanc has been focused on enabling ARM-based technology for HPC, developing both hardware platforms and system software. The latest Mont-Blanc prototypes use system-on-chip (SoC) devices ...
    • Efficient strategies for solving the variable Poisson equation with large contrasts in the coefficients 

      Alsalti Baldellou, Àdel; Álvarez Farré, Xavier; Gorobets, Andrei; Trias Miquel, Francesc Xavier; Oliva Llena, Asensio (2022)
      Text en actes de congrés
      Accés obert
      Discrete versions of Poisson’s equation with large contrasts in the coefficients result in very ill-conditioned systems. Thus, its iterative solution represents a major challenge, for instance, in porous media and multiphase ...
    • Evaluation of enhanced gray area mitigation approaches based on jet aeroacoustics 

      Duben, Alexey; Ruano Pérez, Jesús; Gorobets, Andrei; Rigola Serrano, Joaquim; Trias Miquel, Francesc Xavier (2023-02)
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      Accés obert
      An investigation of various eddy viscosity models for accurate scale-resolving simulation of aerodynamics and aeroacoustics of a turbulent jet is presented. The models are considered from the perspective of solving the ...
    • Fine-scale dynamics in turbulent Rayleigh-Bénard convection 

      Dabbagh, Firas; Trias Miquel, Francesc Xavier; Gorobets, Andrei; Oliva Llena, Asensio (Begell House, 2015)
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      Small-scale universal features captured normally in many turbulent flows have been reviewed in Rayleigh-Bénard convection. Namely, dynamical Lagrangian representations of the velocity gradient tensor invariants have displayed ...
    • Flow topology dynamics in a three-dimensional phase space for turbulent Rayleigh-Bénard convection 

      Dabbagh, Firas; Trias Miquel, Francesc Xavier; Gorobets, Andrei; Oliva Llena, Asensio (2020-02-28)
      Article
      Accés obert
    • From extruded-2D to fully-3D geometries for DNS: a multigrid-based extension of the Poisson solver 

      Gorobets, Andrei; Trias Miquel, Francesc Xavier; Soria Guerrero, Manel; Pérez Segarra, Carlos David; Oliva Llena, Asensio (2010)
      Article
      Accés restringit per política de l'editorial
      Direct numerical simulation (DNS) of incompressible flows is an essential tool for improving the understanding of the physics of turbulence and for the development of better turbulence models. The Poisson equation, the ...
    • HPC² - A fully-portable, algebra-based framework for heterogeneous computing. Application to CFD 

      Álvarez Farré, Xavier; Gorobets, Andrei; Trias Miquel, Francesc Xavier; Borrell Pol, Ricard; Oyarzun Altamirano, Guillermo (Elsevier, 2018-09)
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      Accés obert
      The variety of computing architectures competing in the exascale race makes the portability of codes of major importance. In this work, the HPC2 code is presented as a fully-portable, algebra-based framework suitable for ...
    • Hybrid MPI+OpenMP parallelization of a Navier-Stokes solver for large-scale DNS 

      Gorobets, Andrei; Trias Miquel, Francesc Xavier; Borrell Pol, Ricard; Soria Guerrero, Manel; Oliva Llena, Asensio (2011)
      Comunicació de congrés
      Accés restringit per política de l'editorial
      This work presents a parallel Navier-Stokes solver for the large-scale direct numerical simulation (DNS) of incompressible flows with one periodic direction. It is based on a scalable Poisson solver that combines an FFT ...
    • Hybrid MPI+OpenMP parallelization of an FFT-based 3D Poisson solver that can reach 100000 CPU cores 

      Gorobets, Andrei; Trias Miquel, Francesc Xavier; Borrell Pol, Ricard; Soria Guerrero, Manel; Oliva Llena, Asensio (2011)
      Text en actes de congrés
      Accés obert
      This work is devoted to the development of efficient parallel algorithms for the direct numerical simulation (DNS) of incompressible flows on modern supercomputers. A Poisson solver for problems with one uniform periodic ...
    • Hybrid MPI+OpenMP parallelization of an FFT-based 3D Poisson solver with one periodic direction 

      Gorobets, Andrei; Trias Miquel, Francesc Xavier; Borrell Pol, Ricard; Lehmkuhl Barba, Oriol; Oliva Llena, Asensio (2011-10)
      Article
      Accés restringit per política de l'editorial
      This work is devoted to the development of efficient parallel algorithms for the direct numerical simulation (DNS) of incompressible flows on modern supercomputers. In doing so, a Poisson equation needs to be solved at ...
    • Implementation of a flux-limiter into a fully-portable, algebra-based framework for heterogeneous computing 

      Álvarez Farré, Xavier; Valle Marchante, Nicolás; Gorobets, Andrei; Trias Miquel, Francesc Xavier (2018)
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      During the last years, there has been a signi¿cant increment in the variety of hardware to overcome the power constraint in the context of the exascale challenge. This progress is leading to an increasing hybridisation of ...
    • New differential operators and discretization methods for large-eddy simulation and regularization modeling 

      Trias Miquel, Francesc Xavier; Gorobets, Andrei; Pérez Segarra, Carlos David; Oliva Llena, Asensio (International Association for Computational Mechanics (IACM), 2014)
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      Direct numerical simulations (DNS) of the incompressible Navier-Stokes equations are limited to relatively low-Reynolds numbers. Therefore, dynamically less complex mathematical formulations are necessary for coarse-grain ...
    • New Strategies for Mitigating the Gray Area in Delayed-Detached Eddy Simulation Models 

      Pont Vilchez, Arnau; Duben, Alexey; Gorobets, Andrei; Revell, Alistair; Oliva Llena, Asensio; Trias Miquel, Francesc Xavier (2021-09)
      Article
      Accés obert
      This paper presents a new approach for mitigating the unphysical delay in the Reynolds-averaged Navier–Stokes (RANS) to large-eddy simulation (LES) transition, often referred to as the gray area, which is a common issue ...