Now showing items 1-20 of 32

    • A mechanism for streamwise localisation of nonlinear waves in shear flows 

      Mellibovsky Elstein, Fernando; Meseguer Serrano, Álvaro (2015-09-01)
      Article
      Open Access
      We present the complete unfolding of streamwise localisation in a paradigm of extended shear flows, namely two-dimensional plane Poiseuille flow. Exact solutions of the Navier-Stokes equations are computed numerically and ...
    • Active flow control optimisation on SD7003 airfoil at pre and post-stall angles of attack using synthetic jets 

      Monshi Tousi, Navid; Coma Company, Martí; Bergadà Granyó, Josep Maria; Pons Prats, Jordi; Mellibovsky Elstein, Fernando; Bugeda Castelltort, Gabriel (2021-06-10)
      Article
      Restricted access - publisher's policy
      The use of Active Flow Control (AFC) technologies to modify the forces acting on streamlined bodies is one of the most active research fields in aerodynamics. For each particular application, finding the optimum set of AFC ...
    • Bone tissue properties measurement by reference point indentation in glucocorticoid-induced osteoporosis 

      Mellibovsky, Leonardo; Prieto Alhambra, Daniel; Mellibovsky Elstein, Fernando; Gueerri Fernandez, Roberto; Nogués, Xavier; Randall, Connor; Hansma, Paul K.; Diez Perez, Adolfo (2015-09-01)
      Article
      Open Access
      Glucocorticoids, widely used in inflammatory disorders, rapidly increase bone fragility and, therefore, fracture risk. However, common bone densitometry measurements are not sensitive enough to detect these changes. Moreover, ...
    • Characterization of three-dimensional vortical structures in the wake past a circular cylinder in the transitional regime 

      Sarwar, Wasim; Mellibovsky Elstein, Fernando (2020)
      Article
      Open Access
      The flow past a circular cylinder in the transitional regime at Re = 2000 has been thoroughly investigated via well resolved direct numerical simulation with a spectral element code. Spanwise periodic boundary conditions ...
    • Dynamics on the pipe flow critical threshold 

      Mellibovsky Elstein, Fernando; Meseguer Serrano, Álvaro (2009-07)
      Conference report
      Restricted access - publisher's policy
    • Edge state in pipe flow experiments 

      De Lozar, Alberto; Mellibovsky Elstein, Fernando; Avila, M.; Hof, Björn (2012-05-21)
      Article
      Open Access
      Recent numerical studies suggest that in pipe and related shear flows, the region of phase space separating laminar from turbulent motion is organized by a chaotic attractor, called an edge state, which mediates the ...
    • El enigma de Osborne Reynolds 

      Meseguer Serrano, Álvaro; Mellibovsky Elstein, Fernando (2010-03-01)
      Article
      Restricted access - publisher's policy
      Aunque se sigue desconociendo por qué un fl uido conducido por una tubería se vuelve turbulento, se ha dado un paso importante hacia la resolución del problema, formulado hace ya más de 125 años
    • El problema de Reynolds: transició subcrítica a la turbulència 

      Meseguer Serrano, Álvaro; Mellibovsky Elstein, Fernando (2008-12-30)
      Article
      Open Access
      Fa 125 anys, Osborne Reynolds, matemàtic i professor d’enginyeria de la Universitat de Manchester, va publicar el seu treball experimental i teòric sobre la transició a la turbulència de fluids en moviment dins de canonades. ...
    • 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 ...
    • Una Experiencia de unificación de asignaturas para desplegar PBL (y las quejas que originó) 

      Barrado Muxí, Cristina; Cuadrado Santolaria, Raúl; Delgado Muñoz, Luis; Mellibovsky Elstein, Fernando; Pastor Llorens, Enric; Pérez Batlle, Marcos; Prats Menéndez, Xavier; Rojas Gregorio, José Ignacio; Royo Chic, Pablo; Valero García, Miguel (Universitat Jaume I. Escola Superior de Tecnologia i Ciències Experimentals, 2013-07-10)
      Conference report
      Open Access
      En esta ponencia se describen los aspectos esenciales de una experiencia de unificación de parejas de asignaturas con el objetivo de crear un escenario más adecuado para el despliegue de Aprendizaje Basado en Proyectos. ...
    • Extensional channel flow revisited: a dynamical systems perspective 

      Marqués Truyol, Francisco; Meseguer Serrano, Álvaro; Mellibovsky Elstein, Fernando; Weidman, Patrick (2017-06-07)
      Article
      Open Access
      Extensional self-similar flows in a channel are explored numerically for arbitrary stretching–shrinking rates of the confining parallel walls. The present analysis embraces time integrations, and continuations of steady ...
    • Fluidic oscillators, feedback channel effect under compressible flow conditions 

      Bergadà Granyó, Josep Maria; Baghaei, Masoud; Prakash, Bhanu; Mellibovsky Elstein, Fernando (Multidisciplinary Digital Publishing Institute (MDPI), 2021-09-01)
      Article
      Open Access
      Fluidic oscillators are often used to modify the forces fluid generates on any given bluff body; they can also be used as flow, pressure or acoustic sensors, with each application requiring a particular oscillator ...
    • Fold-pitchfork bifurcation for maps with Z(2) symmetry in pipe flow 

      Marqués Truyol, Francisco; Mellibovsky Elstein, Fernando; Meseguer Serrano, Álvaro (2013-07-11)
      Article
      Open Access
      This study aims to provide a better understanding of recently identified transition scenarios exhibited by traveling wave solutions in pipe flow. This particular family of solutions are invariant under certain reflectional ...
    • From travelling waves to mild chaos: a supercritical bifurcation cascade in pipe flow 

      Mellibovsky Elstein, Fernando; Eckhardt, Bruno (2012-10-25)
      Article
      Restricted access - publisher's policy
      We study numerically a succession of transitions in pipe Poiseuille flow that leads from simple travelling waves to waves with chaotic time-dependence. The waves at the origin of the bifurcation cascade possess a shift-reflect ...
    • Fully nonlinear mode competition in magnetised Taylor-Couette flow 

      Ayats López, Roger; Deguchi, Kengo; Mellibovsky Elstein, Fernando; Meseguer Serrano, Álvaro (2020-08-25)
      Article
      Open Access
      We study the nonlinear mode competition of various spiral instabilities in magnetised Taylor-Couette flow. The resulting finite-amplitude mixed-mode solution branches are tracked using the annular-parallelogram periodic ...
    • Instability mechanisms and transition scenarios of spiral turbulence in Taylor-Couette flow 

      Meseguer Serrano, Álvaro; Mellibovsky Elstein, Fernando; Àvila Cañellas, Marc; Marqués Truyol, Francisco (2009-10)
      Article
      Open Access
      Alternating laminar and turbulent helical bands appearing in shear flows between counterrotating cylinders are accurately computed and the near-wall instability phenomena responsible for their generation identified for the ...
    • NACA 2412 performance modification via using AFC 

      Summ, Thorsten; Prakash, Bhanu; Bergadà Granyó, Josep Maria; Wierschem, Andreas; Mellibovsky Elstein, Fernando (2017)
      Conference report
      Restricted access - publisher's policy
      The NACA 2412 profile was numerically studied via employing 2D-DNS and implementing Active Flow Control (AFC), the Reynolds number considered was 6757, being the angle of attack of 8º. Initially, the basic flow without ...
    • New applications of numerical simulation based on lattice Boltzmann method at high Reynolds numbers 

      An, Bo; Bergadà Granyó, Josep Maria; Mellibovsky Elstein, Fernando; Sang, WM (2020-03-15)
      Article
      Restricted access - publisher's policy
      In order to study the flow behavior at high Reynolds numbers, two modified models, known as the multiple-relaxation-time lattice Boltzmann method (MRT-LBM) and large-eddy-simulation lattice Boltzmann method (LES-LBM), have ...
    • Numerical investigation on the flow around a square cylinder with an upstream splitter plate at low Reynolds numbers 

      An, Bo; Bergadà Granyó, Josep Maria; Mellibovsky Elstein, Fernando; Sang, W.M.; Xi, C. (2020-03-13)
      Article
      Open Access
      The present study focuses on the flow over a 2D square cylinder with a plate placed in front of it. An in-house code using the lattice Boltzmann method was employed for all the simulations presented. Few cases were simulated ...
    • Onset of temporal dynamics within a low reynolds-number laminar fluidic oscillator 

      Sarwar, Wasim; Bergadà Granyó, Josep Maria; Mellibovsky Elstein, Fernando (2021-02-18)
      Article
      Restricted access - publisher's policy
      We investigate the onset of temporal dynamics of a fluidic oscillator (FO) in the laminar regime at very low Reynolds number ( where and are the velocity and channel height at inlet, and is the kinematic viscosity of the ...