Ara es mostren els items 53-72 de 151

    • Fixed grid numerical modelling of frost growth and densification 

      Bartrons Casademont, Eduard; Galione, Pedro; Pérez Segarra, Carlos David (2019-03)
      Article
      Accés obert
      A fixed-grid-porous-media method capable of simulating the growth and densification of frost sheets is here presented. A velocity field is calculated across the entire domain, in which a porous media treatment is given to ...
    • Flamelet mathematical models for non-premixed laminar combustion 

      Carbonell Sánchez, Daniel; Pérez Segarra, Carlos David; Coelho, P.J.; Oliva Llena, Asensio (2009-02-01)
      Article
      Accés restringit per política de l'editorial
      Detailed numerical calculations based on the solution of the full transport equations have been compared with flamelet calculations in order to analyse the flamelet concept for laminar diffusion flames. The goal of this ...
    • Flow and heat transfer in a wall-bounded pin matrix 

      Paniagua Sánchez, Leslye; Oliet Casasayas, Carles; Lehmkuhl Barba, Oriol; Pérez Segarra, Carlos David (Begell House, 2012)
      Text en actes de congrés
      Accés restringit per política de l'editorial
    • 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 ...
    • Frost formation: optimizing solutions under a finite volume approach 

      Bartrons Casademont, Eduard; Pérez Segarra, Carlos David; Oliet Casasayas, Carles (Institute of Physics (IOP), 2016)
      Text en actes de congrés
      Accés obert
      A three-dimensional transient formulation of the frost formation process is developed by means of a finite volume approach. Emphasis is put on the frost surface boundary condition as well as the wide range of empirical ...
    • Heat and moisture insulation by means of air curtains: application to refrigerated chambers 

      Giráldez García, Héctor; Pérez Segarra, Carlos David; Oliet Casasayas, Carles; Oliva Llena, Asensio (Elsevier, 2016-08)
      Article
      Accés obert
      The present study is devoted to the determination of the efficiency of air curtain units (ACUs) applied to heat and moisture insulation of refrigerated chambers. A detailed study of the fluid dynamics and heat and mass ...
    • Implementation of two-equation soot flamelet models for laminar diffusion flames 

      Carbonell Sánchez, Daniel; Oliva Llena, Asensio; Pérez Segarra, Carlos David (2009-01-01)
      Article
      Accés restringit per política de l'editorial
      The two-equation soot model proposed by Leung et al. [K.M. Leung, R.P. Lindstedt, W.P. Jones, Combust. Flame 87 (1991) 289–305] has been derived in the mixture fraction space. The model has been implemented using both ...
    • Improved semi-analytical method for air curtains prediction 

      Giráldez García, Héctor; Pérez Segarra, Carlos David; Rodríguez Pérez, Ivette María; Oliva Llena, Asensio (2013-11)
      Article
      Accés restringit per política de l'editorial
      The present study is devoted to the analysis and prediction of the efficiency of air curtains. The attention is focused on improving existing semi-analytical methods with the information from CFD simulations and experimental ...
    • Improvements on the numerical analysis of viscoplastic-type non-Newtonian fluid flows 

      Carmona Muñoz, Ángel; Lehmkuhl Barba, Oriol; Pérez Segarra, Carlos David; Oliva Llena, Asensio (2014)
      Text en actes de congrés
      Accés obert
      The aim of this work is to delve into the numerical analysis of viscoplastic-type non-Newtonian fluid flows with the objective of carrying out more advanced numerical simulations for them. Specifically, improvements in the ...
    • Influence of rotation on the flow over a cylinder at Re=5000 

      Aljure Osorio, David E.; Rodríguez Pérez, Ivette María; Lehmkuhl Barba, Oriol; Pérez Segarra, Carlos David; Oliva Llena, Asensio (2015-10-15)
      Article
      Accés restringit per política de l'editorial
      The influence of the rotation ratio on the forces acting on a circular cylinder at Re ¼ 5000 has been investigated by means of direct numerical simulations (DNS). Spin ratios in the range 0-5 have been considered. The ...
    • Influence of rotation on the flow over cylinder at RE=5000 

      Aljure Osorio, David E.; Rodríguez Pérez, Ivette María; Lehmkuhl Barba, Oriol; Pérez Segarra, Carlos David; Oliva Llena, Asensio (2014)
      Text en actes de congrés
      Accés obert
    • Large eddy simulation model assessment of the turbulent flow through dynamic compressor valves 

      Estruch Pérez, Olga; Lehmkuhl Barba, Oriol; Rigola Serrano, Joaquim; Oliva Llena, Asensio; Pérez Segarra, Carlos David (2013)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      The present paper attempts the dynamic simulation of the fluid flow through the valve reed taking into account valve movement due to piston displacement. This work widens previous studies based on numerical experiments ...
    • Large eddy simulation of a turbulent diffusion flame: some aspects of subgrid modelling consistency 

      Ventosa Molina, Jordi; Lehmkuhl Barba, Oriol; Pérez Segarra, Carlos David; Oliva Llena, Asensio (2017-04-26)
      Article
      Accés obert
      In the context of Large Eddy Simulation (LES) solely for the momentum transport equation there may be found several models for the turbulent subgrid fluxes. Furthermore, among those relying on the eddy diffusivity approach, ...
    • Large eddy simulation of a turbulent jet diffusion flame using the Flamelet-Progress Variable model 

      Ventosa, Jordi; Lehmkuhl Barba, Oriol; Pérez Segarra, Carlos David; Oliva Llena, Asensio (2013)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      In this work an hydrogen enriched methane flame in a non-premixed configuration is studied, which corresponds to the DLR flame A. Large Eddy Simulation (LES) will be used to numerically analyse the case. Unstructured meshes ...
    • Large-eddy simulation of turbulent dynamic fluid-structure interaction 

      Estruch Pérez, Olga; Lehmkuhl Barba, Oriol; Borrell Pol, Ricard; Pérez Segarra, Carlos David (Begell House, 2012)
      Text en actes de congrés
      Accés restringit per política de l'editorial
    • Low Mach Navier-Stokes equations on unstructured meshes 

      Ventosa Molina, Jordi; Chiva Segura, Jorge; Lehmkuhl Barba, Oriol; Pérez Segarra, Carlos David; Oliva Llena, Asensio (2012)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      Numerical methods for fluxes with strong density variations but with speeds much lower than the sound speed, known as low Mach flows, present some particularities with respect to incompressible formulations. Despite ...
    • Low-frequency variations in the wake of a circular cylinder at Re = 3900 

      Lehmkuhl Barba, Oriol; Rodríguez Pérez, Ivette María; Borrell Pol, Ricard; Pérez Segarra, Carlos David; Oliva Llena, Asensio (2011)
      Comunicació de congrés
      Accés obert
      Flow around cylindrical structures is of relevance for many practical applications. Knowledge of flow-related unsteady loading of such structures is crucial for hydro- and aerodynamic control and design. In order to obtain ...
    • Modelization of a molten salt thermal energy storage for concentrated solar power 

      Vera i Fernández, Jordi; Colomer Rey, Guillem; Sanmartí Perona, Oriol; Pérez Segarra, Carlos David (Scipedia, 2022)
      Text en actes de congrés
      Accés obert
      A numerical model for studying a storage tank for concentrated solar power is presented. The model consists of solving the heat equation for the solid part made from ceramic materials, a one-dimensional model for the molten ...
    • Modelization of the Low-Mach Navier Stokes equations in unstructured meshes 

      Chiva Segura, Jorge; Ventosa, Jordi; Lehmkuhl Barba, Oriol; Pérez Segarra, Carlos David (2011)
      Comunicació de congrés
      Accés restringit per política de l'editorial
      In this paper a Low-Mach number approximation of the Navier Stokes Equations in unstructured meshes is presented. Both staggered and collocated formulations for unstructured grids will be used.The aim is to develop a ...
    • Modular object-oriented methodology for the resolution of molten salt storage tanks for CSP plants 

      Rodríguez Pérez, Ivette María; Pérez Segarra, Carlos David; Lehmkuhl Barba, Oriol; Oliva Llena, Asensio (2013-09)
      Article
      Accés obert
      Two-tank molten salt storages are the most widespread thermal energy storage technology within concentrated solar power plants. In spite of this, there are design aspects such as thermal losses control, optimisation of the ...