Ara es mostren els items 1-20 de 92

  • A coupled volume-of-fluid/level-set method for simulation of two-phase flows in unstructured meshes 

    Balcázar Arciniega, Néstor; Lehmkuhl Barba, Oriol; Jofre Cruanyes, Lluís; Rigola Serrano, Joaquim; Oliva Llena, Asensio (Elsevier, 2016-01)
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    This paper presents a methodology for simulation of two-phase flows with surface tension in the framework of unstructured meshes, which combines volume-of-fluid with level-set methods. While the volume-of-fluid transport ...
  • A filtered kinetic energy preserving finite volumes scheme for compressible flows 

    Baez Vidal, Aleix; Lehmkuhl Barba, Oriol; Pérez Segarra, Carlos David; Oliva Llena, Asensio (2012)
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    The Kinetic Energy Preserving Scheme (KEP) for compressible flows has been shown to solve 1-D shock waves without smearing them. The method does not add numerical diffusion to solutions but, as a counterpart, it needs ...
  • A finite-volume/level-set method for simulating two-phase flows on unstructured grids 

    Balcázar Arciniega, Néstor; Jofre Cruanyes, Lluís; Lehmkuhl Barba, Oriol; Castro González, Jesús; Rigola Serrano, Joaquim (2014-09)
    Article
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    The conservative level-set method for capturing the interface between two fluids is combined with a variable density projection scheme to simulate incompressible two-phase flows on unstructured meshes. All equations are ...
  • A multiple marker level-set method for simulation of deformable fluid particles 

    Balcázar Arciniega, Néstor; Lehmkuhl Barba, Oriol; Rigola Serrano, Joaquim; Oliva Llena, Asensio (2015-09-01)
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    A novel multiple marker level-set method is introduced for Direct Numerical Simulation of deformable fluid particles (bubbles and droplets), which is integrated in a finite-volume framework on collocated unstructured grids. ...
  • A new statistical model for subgrid dispersion in large eddy simulations of particle-laden flows 

    Muela Castro, Jordi; Lehmkuhl Barba, Oriol; Pérez Segarra, Carlos David; Oliva Llena, Asensio (Institute of Physics (IOP), 2016)
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    Dispersed multiphase turbulent flows are present in many industrial and commercial applications like internal combustion engines, turbofans, dispersion of contaminants, steam turbines, etc. Therefore, there is a clear interest ...
  • A parallel three-dimensional radial basis function interpolation method for unstructured dynamic meshes 

    Estruch Pérez, Olga; Lehmkuhl Barba, Oriol; Borrell Pol, Ricard; Pérez Segarra, Carlos David (2011)
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    A radial basis function (RBF) interpolation method is implemented to be applied in computational fluid dynamics (CFD) problems with dynamic meshes. It is compared with the classic springs analogy smoothing, focusing on the ...
  • A PLIC-VOF implementation on parallel 3D unstructured meshes 

    Jofre Cruanyes, Lluís; Lehmkuhl Barba, Oriol; Castro González, Jesús; Oliva Llena, Asensio (2010)
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    The numerical simulation of interfacial and free surface ows is a vast and interesting topic in the areas of engineering and fundamental physics, such as the study of liquid-gas interfaces, formation of droplets, bubbles ...
  • A self-adaptive strategy for the time integration of navier-stokes equations 

    Trias Miquel, Francesc Xavier; Lehmkuhl Barba, Oriol (2011-08)
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    An efficient self-adaptive strategy for the explicit time integration of Navier-Stokes equations is presented. Unlike the conventional explicit integration schemes, it is not based on a standard CFL condition. Instead, the ...
  • Assessment of the symmetry-preserving regularization model on complex flows using unstructured grids 

    Lehmkuhl Barba, Oriol; Borrell Pol, Ricard; Rodríguez Pérez, Ivette María; Pérez Segarra, Carlos David; Oliva Llena, Asensio (2012-05-15)
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    The main objective of the present paper is the assessment of symmetry-preserving regularization models on unstructured meshes. Three different test cases have been studied: the impinging jet flow, the flow past a circular ...
  • CFD simulation of the thermal behavior of a wind mill power generator nacelle 

    Colomer Rey, Guillem; Lehmkuhl Barba, Oriol; Borrell Pol, Ricard; Oliva Llena, Asensio (2009)
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    In this work we use the Large Eddy Simulation model to predict the thermal behavior of the air inside of a wind generator nacelle, where several elements with di erent thermal characteristics are found. Outside air enters ...
  • Combined heat and moisture transfer in buildings systems 

    Damle, Rashmin; Lehmkuhl Barba, Oriol; Rigola Serrano, Joaquim; Oliva Llena, Asensio (2012)
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    Temperature and humidity are the two main parameters indicating the comfort level of the building occupants. Although the effect of temperature is taken into account in thermal simulation of buildings, the moisture transfer ...
  • Comparative study of subfilter scalar dissipation rate and mixture fraction variance models 

    Ventosa Molina, Jordi; Lehmkuhl Barba, Oriol; Pérez Segarra, Carlos David; Muela Castro, Jordi; Oliva Llena, Asensio (2014)
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    Accurate characterisation of mixing at the subfilter level is a critical aspect in many LES combustion models, such as flamelet based and Conditional Moment Closure models. Several models can be found in the literature, ...
  • Detailed numerical model for the resolution of molten salt storage tanks for CSP plants 

    Pérez Segarra, Carlos David; Rodríguez Pérez, Ivette María; Oliva Llena, Asensio; Torras Ortíz, Santiago; Lehmkuhl Barba, Oriol (2012)
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    Considering the state-of-the-art in TES technologies, two-tank indirect system using molten salt is the most widespread within CSP plants. However, current techniques for design and optimization, as well as, for assessing ...
  • Detailed numerical study of turbulent flows in air curtains 

    Jaramillo Ibarra, Julian Ernesto; Pérez Segarra, Carlos David; Lehmkuhl Barba, Oriol; Oliva Llena, Asensio (2010)
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    Air curtains are generally a set of vertical or horizontal plane jets used as ambient separator. In order to prevent entrainment, a good air curtain should provide a jet with low turbulence level, enough momentum to ...
  • Direct numerical simulation and Large-Eddy simulations of the turbulent flow around a NACA-0012 airfoil 

    Lehmkuhl Barba, Oriol; Baez Vidal, Aleix; Rodríguez Pérez, Ivette María; Pérez Segarra, Carlos David (2011)
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    This paper investigates the capabilities of two subgrid-scale (SGS) models for predicting the complex flow in transitional separated bubbles. We consider here the flow over a NACA 0012 airfoil at Reynolds number Re = 5×10 ...
  • Direct numerical simulation of a NACA0012 in full stall 

    Rodríguez Pérez, Ivette María; Lehmkuhl Barba, Oriol; Borrell Pol, Ricard; Oliva Llena, Asensio (2013-10-15)
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    This work aims at investigating the mechanisms of separation and the transition to turbulence in the separated shear-layer of aerodynamic profiles, while at the same time to gain insight into coherent structures formed ...
  • Direct Numerical Simulation of the flow over a sphere at Re = 3700 

    Rodríguez Pérez, Ivette María; Borrell Pol, Ricard; Lehmkuhl Barba, Oriol; Oliva Llena, Asensio; Pérez Segarra, Carlos David (2009)
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    The direct numerical simulation of the flow past a sphere at Re=3700 is presented. The computations are carried out with a parallel unstructured symmetry preserving information for accurate solving complex geometries. As ...
  • Direct numerical simulation of the flow over a sphere at Re = 3700 

    Rodríguez Pérez, Ivette María; Borrell Pol, Ricard; Lehmkuhl Barba, Oriol; Pérez Segarra, Carlos David; Oliva Llena, Asensio (2011-05-19)
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    The direct numerical simulation of the flow over a sphere is performed. The computations are carried out in the sub-critical regime at Re = 3700 (based on the free-stream velocity and the sphere diameter). A parallel ...
  • Direct numerical simulation of the flow over a spherical bubble in a turbulent pipe flow 

    Jofre Cruanyes, Lluís; Balcázar Arciniega, Néstor; Lehmkuhl Barba, Oriol; Borrell Pol, Ricard; Castro González, Jesús (International Association for Computational Mechanics (IACM), 2014)
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    This work aims at investigating, by means of a direct numerical simulation, the flow over a clean spherical bubble fixed on the axis of a turbulent pipe flow. The simulation is performed by means of a parallel unstructured ...
  • Direct Numerical Simulation of the turbulent flow around a NACA 0012 airfoil at different angles of attack 

    Baez Vidal, Aleix; Lehmkuhl Barba, Oriol; Rodríguez Pérez, Ivette María; Pérez Segarra, Carlos David (2011)
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    Direct numerical simulations (DNS) of the flow dynamics over a NACA 0012 airfoil at Reynolds number Re = 5×104 at different angles of attack are presented. The dynamic of the large separation bubble, characterised by laminar ...