Ara es mostren els items 80-99 de 149

    • Memory aware poisson solver for peta-scale simulations with one FFT diagonalizable direction 

      Oyarzun Altamirano, Guillermo; Borrell Pol, Ricard; Trias Miquel, Francesc Xavier; Oliva Llena, Asensio (Institute of Electrical and Electronics Engineers (IEEE), 2017)
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      Problems with some sort of divergence constraint are found in many disciplines: computational fluid dynamics, linear elasticity and electrostatics are examples thereof. Such a constraint leads to a Poisson equation which ...
    • 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)
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      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 ...
    • New subgrid-scale models for large-eddy simulation of Rayleigh-Bénard convection 

      Dabbagh, Firas; Trias Miquel, Francesc Xavier; Gorobets, Andrei; Oliva Llena, Asensio (Institute of Physics (IOP), 2016)
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      At the crossroad between flow topology analysis and the theory of turbulence, a new eddy-viscosity model for Large-eddy simulation has been recently proposed by Trias et al.[PoF, 27, 065103 (2015)]. The S3PQR-model has the ...
    • Non-Oberbeck-Boussinesq effects in a turbulent tall water-filled differentially heated cavity 

      Kizildag, Deniz; Rodríguez Pérez, Ivette María; Trias Miquel, Francesc Xavier; Oliva Llena, Asensio; Pérez Segarra, Carlos David (Begell House, 2015)
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      The present work studies the non-Oberbeck-Boussinesq (NOB) effects in a tall water-filled differentially heated cavity by means of direct numerical simulation. The obtained results reveal significant NOB effects for this ...
    • NUMA-Aware strategies for the efficient execution of CFD simulations on CPU supercomputers 

      Álvarez Farré, Xavier; Gorobets, Andrei; Trias Miquel, Francesc Xavier; Oliva Llena, Asensio (2021)
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      The growing variety of computing architectures and the hybridization of high-performance computing systems encourage the research for portable implementations of numerical methods in simulation codes. However, the pursuit ...
    • NUMA-Aware Strategies for the Heterogeneous Execution of SPMV on Modern Supercomputers 

      Álvarez Farré, Xavier; Gorobets, Andrei; Trias Miquel, Francesc Xavier; Oliva Llena, Asensio (2021)
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      The sparse matrix-vector product is a widespread operation amongst the scientific computing community. It represents the dominant computational cost in many large-scale simulations relying on iterative methods, and its ...
    • Numerical analysis of parcel tracking in large eddy simulation of polydispersed multiphase flows: assessment of different parcel modeling techniques 

      Bahramian, Linda; Trias Miquel, Francesc Xavier; Oliet Casasayas, Carles; Pérez Segarra, Carlos David (2023)
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      In order to assess the impacts of parcel modeling, the Eulerian-Lagrangian method, by using the Particle-In-Cell model, is implemented for a three-dimensional polydispersed two-phase turbulent flow. First, the benchmark ...
    • Numerical assessment of parcel modeling in large eddy simulation for dispersed multiphase flows 

      Bahramian, Linda; Trias Miquel, Francesc Xavier; Oliet Casasayas, Carles; Pérez Segarra, Carlos David (2023)
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      The particle-laden turbulent flow benchmark case of a confined jet by Hishida (1987) was selected for validation purposes of the Eulerian-Lagrangian method in Large Eddy Simulation (LES). After validation, a particle size ...
    • Numerical investigation of the location of maximum erosive wear damage in elbow: Effect of slurry velocity, bend orientation and angle of elbow 

      Zhang, Hao; Tan, Yuanqiang; Yang, Dongmin; Trias Miquel, Francesc Xavier; Jiang, Shengqiang; Sheng, Yong; Oliva Llena, Asensio (2011-02-01)
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    • Numerical investigation on the role of discrete element method in combined LBM-IBM-DEM modeling 

      Zhang, Hao; Tan, Yuanqiang; Shu, Shi; niu, Xiaodong; Trias Miquel, Francesc Xavier; Yang, Dongmin; Li, Hao; Sheng, Yong (Elsevier, 2014-05-01)
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      Particle collisions play a very important role in determining the fluid-particle multiphase flow, and thus it is crucial to treat the particle-particle interaction using a felicitous method in numerical simulations. A novel ...
    • Numerical simulation of turbulence at lower costs: regularization modeling 

      Trias Miquel, Francesc Xavier; Gorobets, Andrei; Soria Guerrero, Manel; Oliva Llena, Asensio (2011)
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      This work is devoted to the development of efficient methods for the numerical simulation of incompressible flows on modern supercomputers. Direct simulation of the Navier-Stokes equations is nowadays an essential tool ...
    • Numerical simulations of turbulent natural convection coupled and uncoupled with radiation 

      Capdevila Paramio, Roser; Lehmkuhl Barba, Oriol; Trias Miquel, Francesc Xavier; Colomer Rey, Guillem; Pérez Segarra, Carlos David (2011)
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      In the present work, turbulent natural convection in a tall differentially heated cavity of aspect ratio 5:1, filled with air (Pr = 0.7) under a Rayleigh number based on the height of 4.5 · 1010, is studied numerically. ...
    • On a checkerboard-free, conservative method for turbulent flows 

      Hopman, Johannes Arend; Alsalti Baldellou, Àdel; Trias Miquel, Francesc Xavier; Rigola Serrano, Joaquim (Begell House, 2023)
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      In computational fluid dynamics (CFD), the checkerboard problem remains a challenging issue when employing collocated grid arrangements for complex geometries. It manifests as oscillatory and nonphysical pressure modes, ...
    • On a conservative solution to checkerboarding: examining the causes of non-physical pressure modes 

      Hopman, Johannes Arend; Alsalti Baldellou, Àdel; Trias Miquel, Francesc Xavier; Oliva Llena, Asensio (European Research Community on Flow, Turbulence, and Conbustion (ERCOFTAC), 2023)
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      In computational fluid dynamics (CFD), the checkerboard problem remains a challenging issue when employing collocated grid arrangements for complex geometries. It manifests as oscillatory and non-physical pressure modes, ...
    • On a conservative solution to checkerboarding: examining the discrete Laplacian kernel using mesh connectivity 

      Hopman, Johannes Arend; Trias Miquel, Francesc Xavier; Rigola Serrano, Joaquim (Springer, 2022)
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      CFD codes that are used for industrial applications commonly use a collocated grid arrangement to calculate the physical flow variables. When using a central differencing gradient (CDG) to discretise the continuous operators ...
    • On a high-order energy-preserving unconditionally stable discretization on collocated unstructured grids 

      Santos Serrano, Daniel; Trias Miquel, Francesc Xavier; Verstappen, R.W.C.P.; Pérez Segarra, Carlos David (European Research Community on Flow, Turbulence, and Conbustion (ERCOFTAC), 2023)
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      In this work, an energy-preserving unconditionally stable fractional step method on collocated unstructured grids is presented. Its formulation is based on preserving the underlying symmetries of the differential operators. ...
    • On a physically-consistent nonlinear subgrid-scale heat flux model for LES of buoyancy driven flows 

      Trias Miquel, Francesc Xavier; Dabbagh, Firas; Gorobets, Andrei; Oliva Llena, Asensio (2018)
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      Small-scale dynamics is the spirit of turbulence physics. It delivers complex mechanisms when turbulence is purely sustained by buoyancy. This takes place in Rayleigh-Bénard convection (RBC). Most of the existing RBC ...
    • On a Proper Tensor-Diffusivity Model for Large-Eddy Simulation of Buoyancy-Driven Turbulence 

      Trias Miquel, Francesc Xavier; Dabbagh, Firas; Gorobets, Andrei; Oliet Casasayas, Carles (Springer, 2020-03-26)
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      In this work, we aim to shed light to the following research question: can we find a nonlinear tensorial subgrid-scale (SGS) heat flux model with good physical and numerical properties, such that we can obtain satisfactory ...
    • On a proper tensor-diffusivity model for large-eddy simulations of buoyancy driven flows 

      Trias Miquel, Francesc Xavier; Dabbagh, Firas; Gorobets, Andrei; Oliva Llena, Asensio (2019)
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