Redondo Apraiz, Jose Manuel
Total activity: 475
Areas of expertise
Applied Physics, Environmental Fluid Dynamics, Fractals, Mixing, Non-Linear Physics, Swimming, Thermoelectricity, Turbulence
h index
21
Professional category
College professor
Doctoral courses
Doctor en Ciencias Fisicas
PhD in Applied Mathematics
University degree
Ciencias Fisicas
Research group
DF - Nonlinear Fluid Dynamics
Department
Department of Applied Physics
School
Barcelona School of Building Construction (EPSEB)
E-mail
redondofa.upc.edu
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1 to 50 of 475 results
  • Thermocapilarity and radiative heat flux oscillations

     Redondo Apraiz, Jose Manuel; Lopez Gonzalez-Nieto, Pilar; Mahjoub, Otman; Ryazantsev, Yuri S.; Garcia Velarde, Manuel
    Topical Problems of Fluid Mechanics
    p. 117-122
    Presentation's date: 2014-02-19
    Presentation of work at congresses

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    We present a detailled experimental study of the thermocapillary motion of an aniline drop in an stably stratified fluid sytem driven by a laser beam. The thermocapillary motion of drops is the result of the temperature dependence of the interfacial tension. If the surface of the drop is subject to thermal gradients, then non-equilibrium surface tension effects appear, which in some cases can move the drop. We measure some of the velocity induced fields , vorticity, oscilations and intermittency of this complex flow. The source of the no uniformity of the temperature of the surface can be, as is in this experiment, the non uniform heating of the floating drop by a laser beam. In recent years, the thermocapillary movement of bubbles and drops under the influence of laser radiation has received more experimental attention thanks to the improvement in the flow visualization techniques.

  • Thermoelectric driven didactic flow experiments

     Redondo Apraiz, Jose Manuel; Sanchez Carcar, Jesus Maria
    Date: 2014-01-01
    Report

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    We present a versatile apparatus that allows students to understand, manipulate and measure many aspects of buoyancy driven convective flows. The basic prototype presented and described in this brochure is a sturdy and simple to use laboratory or demonstration lecture equipment. It consists of a visualization optimized Perspex enclosure of plane area 200mmx 200 mm and 100 mm thickness. Four thermoelectric Peltier effect coolers/heaters are used to generate different types of convective flows, both in steady state situations and in transients. The flow visualization patterns and techniques that are provided and may be used with ease will upgrade your student laboratory to the XXI st century. Here we show the technical details of the experimental apparatus and show some examples of its use in several disciplines.

  • Informe Termoelectricidad BEROTZA : fractal aspects

     Redondo Apraiz, Jose Manuel
    Date: 2013-10-17
    Report

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    We present a description and some applications of the basic relationships that may affect the figure of merit in complex multiscale thermoelectric materials. The success of Onsager¿s Linear relationships between Fluxes and Forces in explaining the reversible Thermoelectric effects and in deriving Kelvin¿s relationships (Onsager 1931) has been extended to include Magneto-Thermo- Electrical effects. Nerst or Nerst-Ettinghausen Effects, among others provide further examples of possible applications in thermal technologies. The way in which the material structure is built with a controllable multifractal aspect, alternating at many different scales the grains which, either due to intrinsic cristaline anisotropy or due to a selective doping produce power relationships between the interfacial line lengths and the areas in 2D, or beween the area of the surface separating subsets of different material properties and the volumes of the respective grains in 3D. The application of these fractal aspects in order to describe fluxes that may be very different when measured at different scales may also be stated in terms of the relationships between fluxes and forces or between fluxes per unit area and gradients perpendicular to that same area. When basic physical properties that are defined in a very different geometrical way, such as masic properties or surface properties, the need of integrating over all possible scales arises in order to avoid singularities in the theory. The effect of minimum and maximum grain size clusters and their geometrical self similarity is studied in terms of non-linear relationships and of higher order cumulants for several of the Magneto-Thermo-Electric (Devies 1952) and Thermo-electric Effects

  • Observation of the thermocapillary motion of a droplet in a laser beam

     Lopez, Pilar; Redondo Apraiz, Jose Manuel; Ryazantsev, Yuri S.; Garcia Velarde, Manuel; González Rubio, Ramón; Ortega Gómez, Francisco
    DOI: 10.1007/978-3-642-34070-3_17
    Date of publication: 2013-06-01
    Book chapter

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    In this Chapter we report on an experimental study of the thermocapillary motion of an aniline drop in an stably stratified fluid system and driven by a laser beam. The thermocapillary motion of drops is the result of the temperature dependence of the interfacial tension. If the surface of the drop is not isothermal gradients of the surface tension appear, which in some cases can move the drop. The source of the no uniformity of the temperature of the surface can be, in particular, the heating of the drop by a laser beam. In the last years, the thermocapillary movement of bubbles and drops under the influence of laser radiation was studied theoretically and experimentally. However, in the literature there is no data on observation of the movement of a single drop in a laser beam. In this paper an experimental methodology is proposed to study such a motion of a drop.

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    Percolation experiments in complex fractal media  Open access

     Redondo Apraiz, Jose Manuel; Tarquis Alfonso, Ana Maria; Cherubini, Claudia; Lopez Gonzalez-Nieto, Pilar; Vila, Teresa
    European Geosciences Union General Assembly
    p. 14224-14225
    Presentation's date: 2013-04-12
    Presentation of work at congresses

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    Series of flow percolation experiments under gravity were performed in different glass model and real karstic media samples. We present a multifractal characterization of the experiments in several parametric non-dimensional flow descriptors. Using the maximum local multifractal dimension as an additional flow indicator. Also experiments on Non laminar flow and transport conditions in fractured and karstified media were performed at Bari. The investigation on hypothesis of non linear flow and non fickian transport in fractured aquifers led to a distinction on the different role of channels and microchannels and of the presence of vortices and eddy trapping. The dominance of the elongated channels produced early arrival times, with the solute traveling along the high velocity channel network. On the other hand in a lumped structured karstic media, the percolation flow produced long tails with local Eddy mixing, entrapment in eddies, and slow flow out of the eddies.

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    SAR measurements of coastal features in the NW Mediterranean  Open access

     Redondo Apraiz, Jose Manuel; Martinez Benjamin, Juan Jose; Diez Rilova, Margarita; Lopez Gonzalez-Nieto, Pilar
    European Geosciences Union General Assembly
    p. 161-162
    Presentation's date: 2013-04-12
    Presentation of work at congresses

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    The Synthetic Aperture Radar (SAR) is a useful tool to study both marine water dynamics and its pollution, this is relevant near the coastline, where river pollution may be also important. Oil spills and natural slicks are detected with SAR to reveal river and vessel pollution as well as the complex eddy and current interaction in the ocean surface near the coastline. In the framework of the ESA and European Union contracts, more than 1000 SAR images of the North-west Mediterranean Sea area taken between December 1996 and December 2008 are presented using self-similar traces that may be used to parametrize mixing at both limits of the Rossby Deformation Radius scale. Results show the ability to identify different SAR signatures and at the same time provide calibrations for the different local configurations of vortices, spirals, oil spills and tensioactive slicks that eventually allow predicting the behaviour of different tracers and pollutants in the NW Mediterranean Sea.

  • A turbulent plume under different experimental conditions: entrainment, veolocity and vorticity fields

     Lopez Gonzalez-Nieto, Pilar; Matulka, Anna Magdalena; Redondo Apraiz, Jose Manuel; Tarquis Alfonso, Ana Maria
    International workshop on nonlinear processes in oceanic and atmospheric flows
    p. 57-59
    Presentation's date: 2012-06-01
    Presentation of work at congresses

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    Turbulent plumes are fluid motions whose primary source of kinetic energy and momentum flux is body forces derived from density inhomogeneities. The plume boundary acts as a phase boundary across which ambient fluid is entrained. The difference between the plume-fluid radial velocity and the total fluid velocity quantifies in a natural way the purely horizontal entrainment flux of ambient fluid into the plume across the phase boundary at the plume edge. At geophysics, it is usual the generation of turbulent plumes as a part of a dispersion process. For example, there are eruptionc plumes, river plumes (into a lake, sea or ocean), mantle plumes, hydrothermal plumes or contaminant plumes, for example. They also are important in engineering (building ventilation processes).

  • Caracterización de la dispersión de contaminantes en la zona costera  Open access

     Diez Rilova, Margarita
    Department of Hydraulic, Maritime and Environmental Engineering, Universitat Politècnica de Catalunya
    Theses

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    En nuestra sociedad los derivados del petróleo son la fuente principal de energía. Los accidentes con hidrocarburos han protagonizado episodios de contaminación trágicos para la biosfera del océano. Se analizan algunos de ellos, sus efectos y sistemas de limpieza. La complejidad de los procesos físicos, químicos o biológicos que actúan sobre el crudo en el mar, hacen difícil su estudio en laboratorio. Para ello se hacen numerosas campañas de campo con distintas escalas y procesos físicos predominantes diferentes: zonas costeras (Delta del Ebro y playa de Vilanova); en aguas confinadas (puerto de Barcelona y puerto de Recife); y en aguas abiertas (Mediterráneo Occidental), con diferentes tecnologías (foto, vídeo, satélite), para seguir trazadores eularianos (manchas de leche y fluoresceína, flotantes o hidrocarburos) y lagrangianos (boyas lastradas), se miden los agentes forzadores: viento, oleaje, marea, etc. y se correlacionan para caracterizar los diferentes escenarios. También se revisa el estado del arte. El tratamiento digital de imágenes de vídeo permite numerosas aplicaciones en el campo de la hidromorfodinámica, pues es posible controlar la evolución espacial y temporal de cualquier parámetro con evidencias visibles y es una técnica no intrusiva que ofrece datos de oleaje de una zona, en contraposición a los datos puntuales de los sensores. Las imágenes sufren numerosas alteraciones, deformaciones, ruidos, etc., que hay que depurar previamente. Los coeficientes de difusión presentan una gran variedad condicionada a la dependencia característica con la escala temporal y espacial de los fenómenos predominantes. Los coeficientes de difusión medidos se agruparon según el número de Reynolds y se hizo una clasificación: hipodifusividad, hiperdifusividad y difusión anómala. Esta caracterización de escenarios permite parametrizar el medio para modelizar su comportamiento y poder predecir su evolución. En el campo del oleaje se pueden obtener espectros de energía y otros parámetros para su caracterización, detectar la morfología de barras sumergidas, identificar corrientes de retorno, caracterizar run-up, etc. En el puerto de Barcelona se tomaron numerosos datos de velocidades de viento (Vv) y corriente (Vc) llegando a una buena correlación entre ambas (Vcx (cm/s)= 2.306 Vvx (m/s)+ 0.148) y constatando que hay una influencia de otros efectos como la marea, reflexión de los muelles o difracción que no se pueden obviar. Las imágenes de Rádar de Apertura sintética SAR permiten detectar episodios de contaminación y analizar la vorticidad a gran escala del medio. Resultó sorprendente el gran número de manchas detectadas. Se comprobó que los vertidos siguen la Ley de Zipp (distribución hiperbólica entre los accidentes y su tamaño). Se vió que los remolinos siguen la dirección de los cañones submarinos. Con el análisis fractal y multifractal del contorno de la mancha se puede caracterizar su origen (antropogénico o natural como masas de plankton) y su envejecimiento o persistencia, etc. Se comprueba que es posible que la intermitencia de la turbulencia pueda parametrizarse mediante medidas fractales y que el uso de momentos de orden superior ayuda a comparar medidas de difusión a distintas escalas mediante la Ley de Richardson Generalizada. Así se relaciona la pendiente del espectro, la intermitencia y la dependencia temporal de la difusión efectiva. Los distintos agentes que producen difusión en el mar sufren interacciones no-lineales complejas. Con todo ello, se pretende contribuir a comprender mejor los procesos de dispersión de los contaminantes en el mar y, por consiguiente, ayudar en la lucha contra este fenómeno.

    In our society the derivatives of petroleum are the main source of energy. The accidents with hydrocarbons have carried out tragic episodes of contamination for the biosphere of the ocean. Some of them, their effects and systems of cleaning are analyzed. The complexity of the physical, chemical or biological processes that act on the oil in the sea, makes their study in laboratory difficult. For it numerous campaigns of field with different scales and different predominant physical processes become: coastal zones (Delta of the Ebro and beach of Vilanova); in confined waters (port of Barcelona and port of Recife); and in open waters (West Mediterranean), with different technologies (photo, video, satellite), to follow Lagrangian tracers (milk spots and fluoresceine, floating or hydrocarbons) and Euler tracers (ballasted buoys), to measure the agents: wind, waves, tide, etc. and they are correlated to characterize the different scenes. Also the state-of-the-art is reviewed. Treatment digital of images of video allows many applications in field of hydromorfodynamics, because it is possible to control the space and temporary evolution of any parameter with visible evidences and is a nonintrusive technique that offers data of a zone, in contrast to the pointing data of the sensors. The images put up with numerous alterations, deformations, noises, etc., that have to purify previously. The diffusion coefficients present/display a great conditional variety to the dependency characteristic with the temporary and space scale of the main phenomena. The measured coefficients of diffusion were grouped according to the Reynolds number and a classification became: hypo-diffusion, hyper-diffusion and anomalous diffusion. This characterization of scenes allows obtaining the waves parameters, the average one to model its behavior and power to predict its evolution. In the field of the waves run-up, etc. can be obtained spectra of energy and other parameters for their characterization, the morphology of submerged bars, identification of return currents. In the port of Barcelona numerous speed data of wind (Vv) and current were taken (Vc) arriving at a good correlation between both (Vcx (cm/s) = 2,306 Vvx (m/s) + 0,148) and stating that an influence of other effects are as the tide, reflection of the wharves or diffraction that cannot be avoided. The images of Radar of synthetic Opening SAR allow to detect episodes of contamination and to analyze the vorticity on great scale of means. Was surprising the great number of spots identifies. It was verified that the spills follow the Law of Zipp (hyperbolic distribution between the accidents and their size). Saw that the eddies follow the direction of the submarine tubes. With the analysis fractal and multifractal of the contour of the spot it is possible to be characterized its origin (human or natural like masses of plankton) and its aging or persistence, etc. It is verified that it is possible that the intermitency of the turbulence can obtain parameters by means of measures fractals and that the use of moments of superior order aid to compare measures of diffusion on different scales by means of the Generalized Law of Richardson. Thus it is related the slope of the phantom, the intermitency and the temporary dependency of the effective diffusion. The different agents who produce diffusion in the sea undergo complex not-linear interactions. It, is tried yet to contribute to include/understand better the

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    Turbulent diffusion and mixing in non-homogeneous environments  Open access

     Redondo Apraiz, Jose Manuel; Diez Rilova, Margarita; Sekula, Emil; Mahjoub, Otman
    European Geosciences Union General Assembly
    p. 1
    Presentation's date: 2012-04-27
    Presentation of work at congresses

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    Many experimental and field studies have been devoted to the understanding of non-homogeneous turbulent dynamics. Activity in this area intensified when the basic Kolmogorov self-similar theory was extended to two-dimensional or quasi 2D turbulent flows such as those appearing in the environment, that seem to control mixing [1,2]. The statistical description and the dynamics of these geophysical flows depend strongly on the distribution of long lived organized (coherent) structures. These flows show a complex topology, but may be subdivided in terms of strongly elliptical domains (high vorticity regions), strong hyperbolic domains (deformation cells with high energy condensations) and the background turbulent field of moderate elliptic and hyperbolic characteristics. It is of fundamental importance to investigate the different influence of these topological diverse regions.

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    Fractal approach of turbulent dispersion  Open access

     Redondo Apraiz, Jose Manuel
    Journées Scientifiques de l'Université du Sud Toulon-Var
    p. 1-7
    Presentation's date: 2012-04-18
    Presentation of work at congresses

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    There are several techniques suitable for measuring and modelling dispersion from scalar or velocity-field measurements in a turbulent flow. Each of these has peculiar features and sometimes, even different scaling, and a careful choice has to be made depending on the kind of information available and needed. A useful way to investigate diffusion is to make use of the fractal and multifractal information that ocean and atmospheric flows provide. Here we present some fractal based techniques, where the velocity and scalar fields are related to the spectral spatial information that they provide and are used to predict diffusivity and mixing.In addition an Eulerian description can be obtained by interpolation from Lagrangian information, which is much easier to model via Kinematic Simulation or synthetic turbulence type models, because the detail velocity field is eventually sampled in a random statistical way in the whole domain during their time evolution. It is not possible to get reliable Lagrangian information using PIV since the transformation from the Eulerian description to the Lagrangian one implies an integration in time of the velocity field, especially when considering phenomena that show high sensitivity to initial conditions (turbulent flows). We show some examples of oil spill dispersion in the ocean surface and discuss several multifractal and scaling approaches.

  • Swimming propulsion due to vortices

     Redondo Apraiz, Jose Manuel; Arellano, Raul; Carrillo Cortes, Jose Alejandro; Matulka, Annia; Ben Mahjoub Akalay, Otman; Sekula, Emil
    Date of publication: 2012-02-15
    Book chapter

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    Postprint (author’s final draft)

  • Mixing efficiency in buoyant flows

     Redondo Apraiz, Jose Manuel; Lopez Gonzalez-Nieto, Pilar; Diez Rilova, Margarita
    Date of publication: 2012-02-15
    Book chapter

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  • New approaches in modeling multiphase flows and dispersion in turbulence, fractal methods and synthetic turbulence

    Date of publication: 2012-01-01
    Book

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    This book series is a collection of the main contributions from the first five workshops held by Ercoftac Special Interest Group on Synthetic Turbulence Models (SIG42), a summary of each workshop can be found in Ercoftac Bulletin, Synthetic turbulence can model diffusion , and was simulated on a one dimensional grid with a random velocity field. Kraichnan continued with a random flow field in three dimensions, and constructed an isotropically random sum of unsteady Fourier waves with distributed frequencies. Most of the applications really started with what was to be called Kinematic Simulation (KS). Kinematic simulation are perhaps the best known of the synthetic turbulence models. They are based on a simplified incompressible velocity field which kinematically simulates the Eulerian velocity field and is generated as a sum of random incompressible Fourier modes with a given wavenumber-energy spectrum. More generally by synthetic turbulence models we mean Lagrangian models for turbulent diffusion which simulate the Lagrangian statistics that would arise from the underlying Eulerian field. Synthetic turbulence has been used as an approach to understand the general mechanisms of turbulent diffusion, but also to make quantitative predictions of relative dispersion and higher order statistical moments. While remaining as simple a model as possible, synthetic turbulence models are expected to capture the essence rather than the details of the bigger picture, synthetic turbulence models have now moved from simple to more complex flows, some are discussed in contributions herein, KS for stratified and rotating flows and other complex turbulent flow Angilella, J.R., Nicolleau, F., Redondo, J.-M.: Synthetic Turbulence Model and Particle-Laden Flows, Ecole de Géologie, Nancy, France. ERCOFTAC Bull. 79, 32¿35 (2009) Redondo, J.-M., Nicolleau, F., Cambon, C.: Synthetic Turbulence Models II, SIG 42 and 35 ERCOFTAC Workshop. ERCOFTAC Bull. 77, 5¿7 (2008)

  • Programa de la "WEEK OF SCIENCE" Madrid 12-16 Sept. 2011

     Redondo Apraiz, Jose Manuel; Ferriz, Antonio; Morozov, Evgeny
    Symposium on Geophysical and Astrophysical Flows and Related Problems
    p. 1-19
    Presentation's date: 2011-09-16
    Presentation of work at congresses

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  • Multiscale analysis of SAR and ASAR river plumes and coastal features

     Redondo Apraiz, Jose Manuel; Sekula, Emil; Martinez Benjamin, Juan Jose
    International Workshop on Science and Applications of SAR Polarimetry and Polarimetric Interferometry
    p. 140-141
    Presentation's date: 2011-01-24
    Presentation of work at congresses

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  • Summer Course and workshop on Environmental Turbulence (2-7 August 2010)

     Lopez Gonzalez-Nieto, Pilar; Tarquis Alfonso, Ana Maria; Redondo Apraiz, Jose Manuel
    DOI: /www.ucm.es/info/fluidos
    Date: 2010-08-02
    Report

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  • Multifractality in the atmospheric boundary layer

     Vindel, Jose M.; Yagüe, C.; Redondo Apraiz, Jose Manuel
    Workshop on Advances in Turbulence
    p. 1
    Presentation's date: 2010-08-02
    Presentation of work at congresses

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  • Richmyer-Meshkov and Rayleigh-Taylor turbulent mixing fronts and instabilities

     Redondo Apraiz, Jose Manuel; GARZON BEDOYA, GERMAN; Rozanov, V.B.; Gushkov, S.
    Workshop on Advances in Turbulence
    p. 1-14
    Presentation's date: 2010-08
    Presentation of work at congresses

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  • Numerical LES models of Richtmyer-Meshkov and Rayleigh-Taylor instabilities

     GARZON BEDOYA, GERMAN; Redondo Apraiz, Jose Manuel; Rozanov, V.B.; Gushkov, S.
    Workshop on Advances in Turbulence
    p. 1-15
    Presentation's date: 2010-08-03
    Presentation of work at congresses

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    ROFI structure in the gulf of Lions and the NW Mediterranean Sea: field and remote sensing observations of surface coherent structures  Open access

     Fraunie, Philippe; Redondo Apraiz, Jose Manuel; Platonov, Alexei; Diez Rilova, Margarita; Matulka, Anna Magdalena
    Workshop on Advances in Turbulence
    p. 1-18
    Presentation's date: 2010-08-04
    Presentation of work at congresses

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    The advances in radar sensors may be applied to study the flow in the region of fresh water influence (ROFI) region of the ocean. The Synthetic Aperture Radar (SAR) is a useful tool that may be used to study both marine water dynamics and its pollution. Oil spills and natural slicks may be detected and processed with advanced computer techniques to reveal vortex dynamics and turbulence spectral characteristics of the complex eddy and current interaction in the ocean surface. In the framework of the European Union contract Clean Seas, more than 300 SAR images of the North-west Mediterranean Sea area taken between December 1996 and December 1998 were analyzed. 255 eddies can be detected under certain conditions and we analyzed statistically the appearance, size and position of vortices in the test area. It is shown that the maximum size of the eddies detected near the coast is limited by the Rossby deformation radius To be discussed and that there is a decrease in size in the coastal waters in the direction of the Liguro-Provenzal current with the largest eddies occurring near the cape of Rosas. The role of submarine canyons in the vortex generation is indicated by the asymmetry of their distribution with respect to the thalwegs. It is demonstrated that useful information of a geometrical nature obtained by SAR satellite images may be used to estimate relevant dynamical parameters of coastal flows

    Postprint (author’s final draft)

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    Multiscale analysis of SAR from the earth surface  Open access

     Redondo Apraiz, Jose Manuel; Tarquis Alfonso, Ana Maria; Matulka, Anna Magdalena; Platonov, Alexei
    Workshop on Advances in Turbulence
    p. 1-8
    Presentation's date: 2010-08
    Presentation of work at congresses

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    The use of Synthetic Aperture Radar (SAR) to investigate the earth’s surface provides a wealth of useful information. Here we will discuss some recent fractal and multi-fractal techniques used to identify oil spills and the dynamic state of the Ocean as well as the mountain structures in the solid earth. It is important both in the Ocean and in the Atmosphere to be able to parametrize mixing at the Rossby Deformation Radius scale (i.e. most energetic eddy scale) to aid in the prediction of pollutant dispersion. Results presented here aim to identify different SAR signatures and at the same time provide calibrations for the different local configurations that allow to predict the behaviour of different tracers in the sea surface, in the atmosphere or in the earth. We also compare different SAR images of the Eastern Pyrenees, evaluating the changes in structure as a function of average height. The multiple correlations between HH HV VV polarizations and the images are used to calculate the fractal dimension with the Box-Counting method. The distribution of the boxes is accomplished systematically for each SAR intensity level, ρ the intersection of these boxes with the images gives N(ρ) boxes with a non void intersection, which may be compared with the standard multifractal formalism.

    Postprint (author’s final draft)

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    Evolution of the Thorpe and Ozmidov scales at the lower atmospheric and planetary boundary layer  Open access

     Lopez Gonzalez-Nieto, Pilar; Cano Marchante, Jose Leandro; Redondo Apraiz, Jose Manuel
    Workshop on Advances in Turbulence
    p. 1-18
    Presentation's date: 2010-08-05
    Presentation of work at congresses

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    Turbulence affects the dynamics of atmospheric processes by enhancing the transport of mass, heat, humidity and pollutants. The global objective of our work is to analyze some turbulent descriptors which reflect the mixing processes in the atmospheric boundary layer (ABL). In this paper we present results related to the Thorpe displacements dT, the maximum Thorpe displacement (dT)max, the Thorpe scale LT and the Ozmidov scale, LO, and their time evolution in the ABL during a day cycle. A tethered balloon was used to obtain vertical profiles of the atmospheric physical magnitudes up to 1000 m. We discuss their vertical and time variability, and also their relationships.

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    Flow structure and resistance in flexible vegetated channels  Open access

     Velasco Montes, David; Bateman Pinzon, Allen; Redondo Apraiz, Jose Manuel
    Workshop on Advances in Turbulence
    p. 1-3
    Presentation's date: 2010-08-05
    Presentation of work at congresses

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    The present paper helps to understand the behaviour of the flow through plants, as a first approximation to the environmental interactions happening in natural rivers.

    Postprint (author’s final draft)

  • Irregularity of wetting fronts in heterogeneous porous media

     Tarquis Alfonso, Ana Maria; Redondo Apraiz, Jose Manuel; Ryansantsev, Yury; Lopez Gonzalez-Nieto, Pilar
    Workshop on Advances in Turbulence
    p. 1
    Presentation's date: 2010-08
    Presentation of work at congresses

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  • The structure of rotating stratified flows

     Redondo Apraiz, Jose Manuel
    International Workshop on the Physics of Compressible Turbulence Mixing
    p. 1-5
    Presentation's date: 2010-07-16
    Presentation of work at congresses

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  • Direct numerical simulation of internal waves formation in highly stratified wake flow

     Houcine, H.; Chaschechkin, Yuli; Fraunie, Philippe; Redondo Apraiz, Jose Manuel; Gharbi, Abdel
    European Conference on Computational Fluid Dynamics
    p. 1
    Presentation's date: 2010-06-16
    Presentation of work at congresses

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  • Oil spill detection and prediction in the NW Mediterranean Sea: new multifractal methods for SAR analysis

     Redondo Apraiz, Jose Manuel; Platonov, Alexei
    European Conference on Computational Fluid Dynamics
    p. 1-12
    Presentation's date: 2010-06-17
    Presentation of work at congresses

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    The oil pollution of Gulf of Lion in the NW Mediterranean has been studied with SAR images during the period 1999 -2005. We have analyzed these SAR images with respect to other surface features such as wind, river plumes, eddies and convergence areas. Some results of our statistical analysis are presented showing that the NW Mediterranean is most polluted along the main ship traffic routes, but comparatively less that near other routes in the Indic and the Pacific. The oils spill index is higher than one. The sizes of the detected oil spills vary over a large range, and if the statistics of the largest accidents are also considered on a longer timescale, we show that Zipf's Law, relating the frequency and the size of the spill in a hyperbolic fashion is applicable. Advanced image analysis techniques, such as the calculation of the multi-fractal dimensions of the observed SAR signatures, have been applied to distinguish between natural slicks and antropogenic spills. Fractal dimensions can also be used to predict the time of release of the spill, non-dimensionalised with local turbulent dissipation. The multi-scale appearance and the topological structure of the slicks and spills may also be used as a useful measure of the diffusivity, yielding additional information which in turn may improve automated detection algorithms and be used in numerical models.

    Postprint (author’s final draft)

  • Multifractal analysis of SAR of the ocean surface, currents, eddy structure, oil slicks and diffusivity analysis

     Redondo Apraiz, Jose Manuel; Grau, J.; Matulka, Anna Magdalena; Platonov, Alexei
    European Conference on Computational Fluid Dynamics
    p. 1-8
    Presentation's date: 2010-06-17
    Presentation of work at congresses

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    Postprint (author’s final draft)

  • Scaling and isotropy in the inertial range of atmospheric turbulence

     Marino, Rafaelle; Sorriso, Luca; Redondo Apraiz, Jose Manuel; Yague, Carlos
    European Geosciences Union General Assembly
    p. 8725
    Presentation's date: 2010-05-05
    Presentation of work at congresses

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  • Mixing in Richtmyer Meshkov and Rayleigh Taylor fronts

     Redondo Apraiz, Jose Manuel; Vila, Teresa; Garzon, G.; Rozanov, V.B.; Gushkov, S.
    European Geosciences Union General Assembly
    p. 14565-
    Presentation's date: 2010-05-05
    Presentation of work at congresses

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  • Flow percolation in non homogeneous Hele-Shaw flows

     Lopez Gonzalez-Nieto, Pilar; Redondo Apraiz, Jose Manuel; Hernández, David; Tarquis Alfonso, Ana Maria
    European Geosciences Union General Assembly
    p. 15080
    Presentation's date: 2010-05-06
    Presentation of work at congresses

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  • Hierarchy compensation of non-homogeneous intermittent atmospheric turbulence

     Redondo Apraiz, Jose Manuel; Ben Mahjoub Akalay, Otman; Rodriguez Cantalapiedra, Inmaculada
    European Geosciences Union General Assembly
    p. 1755
    Presentation's date: 2010-05-04
    Presentation of work at congresses

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  • Environmental geosciences lectures and transversal public workshops

     Redondo Apraiz, Jose Manuel; Redondo, A.; Babiano, Armando
    European Geosciences Union General Assembly
    p. 14513-
    DOI: doi 10.1029/2009GL03748
    Presentation's date: 2010-05-04
    Presentation of work at congresses

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  • Gravity and turbidity currents

     Bolster, Diogo; Bateman Pinzon, Allen; Redondo Apraiz, Jose Manuel; Bezerra Menezes, Maria Ozilea
    European Geosciences Union General Assembly
    p. 1
    Presentation's date: 2010-05-02
    Presentation of work at congresses

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  • Turbulent structure in environmental flows: effects of stratification and rotation  Open access

     Matulka, Anna Magdalena
    Department of Engineering Design, Universitat Politècnica de Catalunya
    Theses

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    Several series of experiments in stratified and in rotating/stratified decaying flows after a grid is used to stir the two layer stable fluid brine and fresh water set up. We measure by comparing the gained potential energy with the available kinetic energy AKE, the relative efficiency of mixing. The experiments in stratified rotating flows with grid driven turbulence were both periodic (quasi stationary) and non-monotonic (decaying) forcing. This thesis compares experimental, numerical and field observations on the structure and Topology of the Stratified Rotating Flows as well as their decay, the horizontal spectra changes appreciable with slopes from 1.1 to 5, but vorticity and local circulation, and also the initial topology and forcing of the flow. A detailed study of the vorticity decay and vortex and energy structure has been performed, the new results show that neither stratified nor rotating flows exhibit pure 2D structures. The work parameterizes the role of the Richardson number and the Rossby number, both in the experiments and in the ocean visualizations is very important. The conditions of vortex decay show the effects of the internal waves in the decay turbulent conditions both for stratified and rotating flows. The parameter space (Re,Ri,Ro) has been used to interpret many previously disconnected explanations of the 2D-3D turbulent behaviour. The comparison of numerical simulations with experiments has allowed implementing new theoretical aspects of the interaction between waves and vortices finding the surprising and very interesting result that these interactions depend on the level of enstrophy. This also leads to new ways of using multifractal analysis ad intermittency in ocean environmental observations. A large collection of SAR images obtained from three European coastal areas were used for routine satellite analysis by SAR and other sensors, which seem very important to build seasonal databases of the dynamic conditions of ocean mixing. The topology of the basic flow is very important and in particular the topology of the vortices and their decay which depends on ambient factors such as wave activity, wind and currents. We find more realistic estimates of the spatial/temporal non-homogeneities (and intermittency obtained as spatial correlations of the turbulent dissipation); these values are used to parameterize the sea surface turbulence, as well as a laboratory experiments at a variety of scales. Using multi-fractal geometry as well, we can establish now a theoretical pattern for the turbulence behaviour that is reflected in the different descriptors. Vorticity evolution is smoother and different than that of scalar or tracer density. The correlation between the local Ri and the fractal dimension detected from energy or entropy is good. Using multi-fractal geometry we can also establish certain regions of higher local activity used to establish the geometry of the turbulence mixing that needs to be studied in detail when interpreting the complex balance between the direct 3D Kolmogorov type cascade and the Inverse 2D Kraichnan type cascade.

  • Diffusion and scaling in the ocean surface

     Diez, Margarita; Bezerra, Maria Ozilea; Vila, Teresa; Castilla Lopez, Roberto; Redondo Apraiz, Jose Manuel
    Topical Problems of Fluid Mechanics
    p. 31-39
    Presentation's date: 2010-02-10
    Presentation of work at congresses

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  • Vortex decay in stratified flows

     Redondo Apraiz, Jose Manuel; Matulka, Anna Magdalena; Carrillo Cortes, Jose Alejandro
    Topical Problems of Fluid Mechanics
    p. 127-130
    Presentation's date: 2010-02-11
    Presentation of work at congresses

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  • Workshop in Environmental and Geo-Astrophysical Turbulence

     Carrillo Cortes, Jose Alejandro; Sekula, Emil; Castilla Lopez, Roberto; Ben Mahjoub Akalay, Otman; Sanchez Ariz, Miguel A.; Rodriguez Cantalapiedra, Inmaculada; Redondo Apraiz, Jose Manuel
    Competitive project

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  • Editorial: advances in environmental turbulence

     Redondo Apraiz, Jose Manuel; Rodriguez Cantalapiedra, Inmaculada; Carrillo Cortes, Jose Alejandro
    Environmental Turbulence - Campus Universitari de la Mediterrania
    p. 1-4
    Presentation's date: 2009-06-15
    Presentation of work at congresses

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  • Structure of 3D turbulent wall jets: acoustic doppler velocity measurements

     Sekula, Emil; Redondo Apraiz, Jose Manuel
    Environmental Turbulence - Campus Universitari de la Mediterrania
    p. 123-133
    Presentation's date: 2009-06-15
    Presentation of work at congresses

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    The main aim of this research is to understand and describe key aspects of the structure of turbulent jets and plumes and their interaction with coherent structures together with the effects connected with them (for example boundary layer - jet interactions). The present work is based principally on experiments. We will discuss and compare here the different series of detailed experiments that have been performed in the Laboratory of Fluid Dynamics of the UPC. Measurements of the 3 components of turbulent velocity and their spectra are presented in order to obtain a basic understanding on the interaction that leads to mixing and mass transport in wall jets, where there is coupling between the boundary and the jet or free shear layer structure. We aim to compare different wall and boundary effects on the structure of jets including vorticity production. We present ADV velocity measurements along the centreline of wall jets and compare mean and fluctuating velocity components as well as their PDF’s and spectra. The turbulent interactions between the jet structure and the boundary layer structure generated by the wall are discussed taking into account both the inverse and direct cascades of the jets as a function of their distance to the wall. These complex non homogeneous jets occur in many industrial and environmental applications and elucidating their structure will be useful for better estimates of entrainment, mixing efficiency and other useful parameters. The 3D turbulent wall jet configuration occurs in several applications such as aeronautics design, heating, cooling, ventilation and environmental fluid dynamics

  • Oil spill detection and prediction in the NW Mediterranean Sea, multifractal methods for space based SAR analysis

     Redondo Apraiz, Jose Manuel; Matulka, Annia; Platonov, Alexei
    Environmental Turbulence - Campus Universitari de la Mediterrania
    p. 100-113
    Presentation's date: 2009-06-15
    Presentation of work at congresses

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    This paper presents a statistical analysis of the oil spill detection in European coastal waters, as well as a methodological description on how to distinguish by means of multi-fractal analysis oil spills and biological tensioacive activity in the ocean surface. We discuss different satellite detected oil spills and their distribution in size. The detectability of the oil by SAR derives from the decrease in roughness of the ocean surface at small wavelengths and depends strongly on the wind speed as well as other varying environmental conditions. In particular, we concentrate on the use of scaling approaches to discriminate between antropogenyc oil spills and natural slicks, also named as look-alikes SAR detections.

  • The inertial range of atmospheric turbulence

     Marino, Rafaelle; Sorriso, Luca; Redondo Apraiz, Jose Manuel; Yague, Carlos; Carbone, V; Noullez, A.
    European Geosciences Union General Assembly
    p. 677-
    Presentation's date: 2009-04-19
    Presentation of work at congresses

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  • Multifractal discrimination of 2D-3D turbulent processes in the ocean surface by SAR imaging

     Platonov, Alexei; Sekula, Emil; Redondo Apraiz, Jose Manuel
    Topical Problems of Fluid Mechanics
    p. 1-6
    Presentation of work at congresses

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  • Multifractal analysis of SAR of the ocean surface, currents, eddy structure, oil slicks and diffusivity analysis

     Redondo Apraiz, Jose Manuel
    II International Workshop on Marine Technology (MARTECH 2007)
    Presentation's date: 2007-11-05
    Presentation of work at congresses

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  • Aplicaciones Informáticas y simulación visual 2002/2007

     Monedero Isorna, Francisco Javier A.; Redondo Apraiz, Jose Manuel; Vila Robert, Jorge
    Collaboration in exhibitions

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  • Vortex Structure in the North of the Ebro Delta Shelf (NW Mediterranean Sea)

     Platonov, Alexei; Carrillo Cortes, Jose Alejandro; Redondo Apraiz, Jose Manuel
    European Geosciences Union General Assembly
    p. 1-2
    Presentation's date: 2007-04-25
    Presentation of work at congresses

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  • Intermittency of ABL turbulence

     Rodriguez Cantalapiedra, Inmaculada; Yague, C; Mahoub, B; Redondo Apraiz, Jose Manuel
    European Geosciences Union General Assembly
    p. 23-24
    Presentation's date: 2007-04-15
    Presentation of work at congresses

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