Now showing items 1-20 of 58

    • A one-phase Stefan problem with size-dependent thermal conductivity 

      Font Martínez, Francesc (2018-07-02)
      Article
      Open Access
      In this paper a one-phase Stefan problem with size-dependent thermal conductivity is analysed. Approximate solutions to the problem are found via perturbation and numerical methods, and compared to the Neumann solution for ...
    • A refined statistical cloud closure using double-Gaussian probability density functions 

      Naumann, Ann Kristin; Seifert, Alex; Mellado González, Juan Pedro (2013-10-08)
      Article
      Open Access
      We introduce a probability density function (PDF)-based scheme to parameterize cloud fraction, average liquid water and liquid water flux in large-scale models, that is developed from and tested against large-eddy simulations ...
    • A robust procedure for Damage detection from strain measurements based on Principal Component Analysis 

      Güemes Gordo, Alfredo; Sierra Pérez, Julián; Rodellar Benedé, José; Mujica Delgado, Luis Eduardo (2013-04-17)
      Article
      Restricted access - publisher's policy
      FBGs are excellent strain sensors, because of its low size and multiplexing capability. Tens to hundred of sensors may be embedded into a s tructure, as it has already been demonstrated. Nevertheless, they only afford ...
    • Application of an ALE formulation for density-dependent hyperelastic-plastic models to the simulation of powder compaction processes 

      Pérez Foguet, Agustí; Rodríguez Ferran, Antonio; Huerta, Antonio (2001)
      Conference report
      Open Access
      Different quasi-static cold compaction processes of powders have been simulated with a density-dependent plastic model. The model is formulated within the framework of isotropic finite strain multiplicative hyperelastoplasticity. ...
    • Arbitrary lagrangian-eulerian finite element analysis of strain localization in transient problems 

      Pijaudier-Cabot, Gilles; Bode, L; Huerta, Antonio (John Wiley & Sons, 1995-10)
      Article
      Open Access
      Non-local models guaranty that finite element computations on strain softening materials remain sound up to failure from a theoretical and computational viewpoint. The non-locality prevents strain localization with zero ...
    • Arbitrary Lagrangian–Eulerian (ALE) formulation for hyperelastoplasticity 

      Rodríguez Ferran, Antonio; Pérez Foguet, Agustí; Huerta, Antonio (John Wiley & Sons, 2002)
      Article
      Open Access
      The arbitrary Lagrangian–Eulerian (ALE) description in non-linear solid mechanics is nowadays stan- dard for hypoelastic–plastic models. An extension to hyperelastic–plastic models is presented here. A fractional-step ...
    • Controlling chaotic transport in two-dimensional periodic potentials 

      Chacon, R.; Lacasta Palacio, Ana María (2010-10-07)
      Article
      Open Access
      We uncover and characterize different chaotic transport scenarios in perfect two-dimensional periodic potentials by controlling the chaotic dynamics of particles subjected to periodic external forces in the absence of a ...
    • Correlation studies for B-spline modeled F2 Chapman parameters obtained from FORMOSAT-3/COSMIC data 

      Limberger, Marco; Liang, W; Schmidt, Michael; Dettmering, D; Hernández Pajares, Manuel; Hugentobler, U (2014)
      Article
      Open Access
      The determination of ionospheric key quantities such as the maximum electron density of the F2 layer NmF2, the corresponding F2 peak height hmF2 and the F2 scale height HF2 are of high relevance in 4-D ionosphere modeling ...
    • Direct Numerical Simulation of evaporative cooling at the lateral boundary of shallow cumulus clouds 

      Abma, Dick; Heus, Thijs; Mellado González, Juan Pedro (2013-07-23)
      Article
      Open Access
      This study investigates the dynamics of the subsiding shell at the lateral boundary of cumulus clouds, focusing on the role of evaporative cooling. Since the size of this shell is well below what large-eddy simulations can ...
    • Dynamical sectors for a spinning particle in AdS(3) 

      Batlle Arnau, Carles; Gomis, Jaoquim; Kamimura, kiyoshi; Zanelli, Jorge (American Physical Society, 2014-09-12)
      Article
      Open Access
      We consider the dynamics of a particle of mass M and spin J in AdS(3). The study reveals the presence of different dynamical sectors depending on the relative values of M, J and the AdS(3) radius R. For the subcritical ...
    • Dynamics of Many-Body Quantum Systems 

      Giménez Grau, Aleix (Universitat Politècnica de Catalunya, 2015-07-03)
      Bachelor thesis
      Open Access
      We study the ground state and the excitations of quantum bose systems. The hypernetted chain equations (HNC) are introduced and we show that the methods based on them produce acceptable approximations of the static structure ...
    • Experimental and numerical characterization of metallic studs 

      Poblet-Puig, Jordi; Guigou-Carter, C; Villot, M; Rodríguez Ferran, Antonio (European Acoustics Association, 2006)
      Conference report
      Open Access
      In this paper, the characterization of metallic studs used to mount lightweight double wall systems is studied both experimentally and numerically. The metallic studs are usually considered by introducing translational and ...
    • Exponential stability in thermoelasticity with microtemperatures 

      Sánchez Casas, José Pablo; Quintanilla de Latorre, Ramón (2003)
      Article
      Open Access
      This article is concerned with a linear theory for elastic materials with inner structure, whose particles in addition to the classical displacement, possess microtemperatures. In the main part of the paper we restrict ...
    • Factorization of the Fourier transform of the pressure-Poisson equation using finite differences in colocated grids 

      Mellado González, Juan Pedro; Ansorge, Cedrick (Wiley-VCH, 2012-02-29)
      Article
      Open Access
      The zero-divergence constraint on the velocity field in the numerical simulation of incompressible flows can be reduced, in certain cases, to a set of one-dimensional linear difference equations for the pressure. These ...
    • Flow computations on imprecise terrains 

      Driemel, Anne; Haverkort, Herman; Löffler, Maarten; Silveira, Rodrigo Ignacio (Springer Verlag, 2011)
      Conference report
      Restricted access - confidentiality agreement
      We study water flow computation on imprecise terrains. We consider two approaches to modeling flow on a terrain: one where water flows across the surface of a polyhedral terrain in the direction of steepest descent, and ...
    • Geometric Hamilton-Jacobi theory for higher-order autonomous systems 

      Colombo, Leonardo; de León, Manuel; Prieto Martínez, Pedro Daniel; Román Roy, Narciso (2013-09-09)
      External research report
      Open Access
      The geometric framework for the Hamilton-Jacobi theory is used to study this theory in the ambient of higher-order mechanical systems, both in the Lagrangian and Hamiltonian formalisms. Thus, we state the corresponding ...
    • Geometric Quantization of real polarizations via sheaves 

      Miranda Galcerán, Eva; Presas, Francisco (2013-01)
      External research report
      Open Access
      In this article we develop tools to compute the Geometric Quantization of a symplectic manifold with respect to a regular Lagrangian foliation via sheaf cohomology. The starting point is the definition of representation ...
    • Gravitational Particle Production in Massive Chaotic Inflation and the Moduli Problem 

      Haro Cases, Jaume; Elizalde, Emilio (2012-02)
      Article
      Restricted access - publisher's policy
      Particle production from vacuum fluctuations during inflation is briefly revisited. The moduli problem occurring with light particles produced at the end of inflation is addressed, namely the fact that some results are in ...
    • Groupoids and Faà di Bruno formulae for Green functions in bialgebras of trees 

      Gálvez Carrillo, Maria Immaculada; Kock, Joachim; Tonks, Andrew (2014)
      Article
      Restricted access - publisher's policy
      We prove a Faà di Bruno formula for the Green function in the bialgebra of P-trees, for any polynomial endofunctor P. The formula appears as relative homotopy cardinality of an equivalence of groupoids.