Now showing items 1-20 of 64

  • Análisis multifractal de procesos autosimilares : imágenes de satélite e inestabilidades baroclinas 

    Redondo Apraiz, José Manuel; Busquets Grau, Joan; Platónov, Alexéi Konstantínovich; Garzón Bedoya, Germán (2008-05-05)
    Article
    Open Access
  • A new subgrid characteristic length for turbulence simulations on anisotropic grids 

    Trias Miquel, Francesc Xavier; Gorobets, Andrei; Silvis, Maurits; Verstappen, Roel; Oliva Llena, Asensio (2017-11-29)
    Article
    Open Access
    Direct numerical simulations of the incompressible Navier-Stokes equations are not feasible yet for most practical turbulent flows. Therefore, dynamically less complex mathematical formulations are necessary for coarse-grained ...
  • A priori study of subgrid-scale features in turbulent Rayleigh-Bénard convection 

    Dabbagh, Firas; Trias Miquel, Francesc Xavier; Gorobets, Andrei; Oliva Llena, Asensio (2017-10-06)
    Article
    Open Access
    At the crossroad between flow topology analysis and turbulence modeling, a priori studies are a reliable tool to understand the underlying physics of the subgrid-scale (SGS) motions in turbulent flows. In this paper, ...
  • A simple approach to discretize the viscous term with spatially varying (eddy-)viscosity 

    Trias Miquel, Francesc Xavier; Gorobets, Andrei; Oliva Llena, Asensio (2013-11-15)
    Article
    Restricted access - publisher's policy
    A simple approach to discretize the viscous dissipation term in the incompressible Navier–Stokes equations with spatially varying viscosity is presented. Unlike the case where the viscosity remains constant, its discretization ...
  • Atmospheric-turbulence-induced power-fade statistics for a multiaperture optical receiver 

    Belmonte Molina, Aniceto; Comerón Tejero, Adolfo; Rubio, Juan Antonio; Fernández (OPTICAL SOC AMER, 1997-01-31)
    Article
    Open Access
    To estimate the probability distributions of power fades, we consider two basic types of disturbance in electromagnetic wave propagation through atmospheric turbulence: wave-front intensity fluctuations and wave-front ...
  • Blending regularization and large-eddy simulation. From homogeneous isotropic turbulence to wind farm boundary layers 

    Folch Flórez, David; Trias Miquel, Francesc Xavier; Gorobets, Andrei; Oliva Llena, Asensio (2013)
    Conference lecture
    Restricted access - publisher's policy
    The incompressible Navier-Stokes equations form an excellent mathematical model for turbulent flows. However, direct simulations at high Reynolds numbers are not feasible because the convective term produces far too many ...
  • Building a proper tensor-diffusivity model for large-eddy simulation of buoyancy-driven flows 

    Trias Miquel, Francesc Xavier; Dabbagh, Firas; Gorobets, Andrei; Oliva Llena, Asensio (International Centre for Numerical Methods in Engineering (CIMNE), 2018)
    Conference report
    Restricted access - publisher's policy
    In this work, we plan to shed light on the following research question: can we ¿nd a nonlinear tensorial subgrid-scale (SGS) heat ¿ux model with good physical and numerical properties, such that we can obtain satisfactory ...
  • Building proper invariants for eddy-viscosity subgrid-scale models 

    Trias Miquel, Francesc Xavier; Folch, David; Gorobets, Andrei; Oliva Llena, Asensio (2015-06-23)
    Article
    Open Access
    Direct simulations of the incompressible Navier-Stokes equations are limited to relatively low-Reynolds numbers. Hence, dynamically less complex mathematical formulations are necessary for coarse-grain simulations. ...
  • Detached-eddy simulation of a wall-mounted cylinder flow 

    Contel Anguix, Alejandro (Universitat Politècnica de Catalunya, 2016-09-14)
    Bachelor thesis
    Open Access
    Covenantee:  Technische Universität München
    The aim of this project is to study the effect of different turbulence models on the detachment point on the cylinder surface and the vortex shedding frequencies. The turbulence models considered are Spallart-Allmaras DDES, ...
  • Detailed numerical study of turbulent flows in air curtains 

    Jaramillo Ibarra, Julian Ernesto; Pérez Segarra, Carlos David; Lehmkuhl Barba, Oriol; Oliva Llena, Asensio (2010)
    Conference lecture
    Restricted access - publisher's policy
    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 of a fully developed turbulent square duct flow up to Re-tau=1200 

    Zhang, Hao; Trias Miquel, Francesc Xavier; Gorobets, Andrey; Tan, Yuanqiang; Oliva Llena, Asensio (2015-08-01)
    Article
    Open Access
    Various fundamental studies based on a turbulent duct flow have gained popularity including heat transfer, magnetohydrodynamics as well as particle-laden transportation. An accurate prediction on the turbulent flow field ...
  • 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)
    Article
    Open Access
    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 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)
    Conference report
    Restricted access - publisher's policy
    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 viscoplastic-type non-Newtonian fluid flows in stenosed arteries 

    Carmona Muñoz, Ángel; Lehmkuhl Barba, Oriol; Pérez Segarra, Carlos David; Oliva Llena, Asensio (2013)
    Conference report
    Restricted access - publisher's policy
    The aim of this work is to provide DNS solutions for turbulence flows of viscoplastic-type non-Newtonian fluids and thus contribute to gain insight into the underlying physics of the non-Newtonian turbulent flows. This ...
  • Emergence of spatio-temporal dynamics from exact coherent solutions in pipe flow 

    Ritter, Paul; Mellibovsky Elstein, Fernando; Àvila Cañellas, Marc (2016-08-12)
    Article
    Open Access
    Turbulent-laminar patterns are ubiquitous near transition in wall-bounded shear flows. Despite recent progress in describing their dynamics in analogy to non-equilibrium phase transitions, there is no theory explaining ...
  • Estudi aerodinàmic d'un edifici. Comparació de resultats obtinguts amb diferents programaris de CFD 

    Ricart Rius, Marc; Subirats Soler, Monica (Universitat Politècnica de Catalunya, 2009-07-24)
    Master thesis (pre-Bologna period)
    Restricted access - author's decision
  • Estudio de los cambios en el comportamiento motriz de una población de lenguado (Solea senegalensis) en diferentes situaciones de cultivo 

    Crespo Abril, Maria (Universitat Politècnica de Catalunya, 2014-07-07)
    Bachelor thesis
    Open Access
    The knowledge of the farmed fish behavior is very important to control and improve their growth and reproduction. In this study, Doppler Acoustic Velocimeter (ADV) has been proposed as a tool to study the behavior of sole ...
  • Experimental analysis of the flow dynamics in the suction chamber of an external gear pump 

    Ertürk, Nihal; Vernet, Anton; Castilla López, Roberto; Gámez Montero, Pedro Javier; Ferre, Josep Anton (2011-01)
    Article
    Restricted access - publisher's policy
    Time-Resolved Particle Image Velocimetry (TRPIV) has been used to investigate the flow inside the suction chamber of an external gear pump where the movement of the fluid through the pump is maintained by the rotation of ...
  • EXPERIMENTS AND SIMULATIONS OF MAXIMAL SCULLING PROPULSION: VORTICITY IMPULSE IN HUMAN BIOMECHANICS 

    Furmanek, Petr; Redondo Apraiz, José Manuel; García Carrillo, Àgueda; Tellez Alvarez, Jackson David; Arellano, Raul; Sanchez, Jesus maria (2016)
    Conference report
    Open Access
    The detailed study of the turbulence and the fluid flow in sport is an open and exciting field of research, in particular in swimming and aquatic sports there is a wealth of new techniques that may aid performance. In ...
  • Fine-scale dynamics in turbulent Rayleigh-Bénard convection 

    Dabbagh, Firas; Trias Miquel, Francesc Xavier; Gorobets, Andrei; Oliva Llena, Asensio (Begell House, 2015)
    Conference report
    Restricted access - publisher's policy
    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 ...