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  • High-order mesh generation on CAD geometries

     Gargallo Peiró, Abel; Roca Navarro, Xevi; Peraire Guitart, Jaume; Sarrate Ramos, Jose
    International Conference on Adaptive Modeling and Simulation
    Presentation's date: 2013-06-04
    Presentation of work at congresses

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    We present a technique to extend Jacobian-based distortion (quality) measures for planar triangles to high-order isoparametric elements of any interpolation degree on CAD parameterized surfaces. The resulting distortion (quality) measures are expressed in terms of the parametric coordinates of the nodes. These extended distortion (quality) measures can be used to check the quality and validity of a high-order surface mesh. We also apply them to simultaneously smooth and untangle high-order surface meshes by minimizing the extended distortion measure. The minimization is performed in terms of the parametric coordinates of the nodes. Thus, the nodes always lie on the surface. Finally, we include several examples to illustrate the application of the proposed technique.

  • Preserving isotropic element size functions in adaptivity, quadrilateral and hexahedral mesh generation

     Ruiz Girones, Eloi; Roca Navarro, Xevi; Sarrate Ramos, Jose
    Advances in engineering software
    Date of publication: 2013
    Journal article

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    In electric circuit theory, it is of great interest to compute the effective resistance between any pair of vertices of a network, as well as the Kirchhoff Index. During the last decade these parametres have been applied in Organic Chemistry as natural structural indexes different from the usual ones in order to achieve an improvement in the discrimination between different molecules which have similar structural behaviours. Moreover, a wide range of generalized Kirchhoff Indexes for some networks have been introduced. The objective of the present work is to obtain the Kirchhoff Index for a wide range of composite networks known as cluster networks

  • Least-squares approximation of affine mappings for sweep mesh generation: Functional analysis and applications

     Roca Navarro, Xevi; Sarrate Ramos, Jose
    Engineering with computers
    Date of publication: 2013-01
    Journal article

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  • Defining quality measures for mesh optimization on parameterized CAD surfaces

     Gargallo Peiró, Abel; Roca Navarro, Xevi; Peraire, Jaime; Sarrate Ramos, Jose
    International Meshing Roundtable
    Presentation's date: 2012-10-07
    Presentation of work at congresses

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    A new procedure to smooth and untangle meshes on parameterized surfaces  Open access

     Gargallo Peiró, Abel; Roca Navarro, Xevi; Sarrate Ramos, Jose
    European Congress on Computational Methods in Applied Sciences and Engineering
    Presentation's date: 2012-09-10
    Presentation of work at congresses

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    We present a technique to extend any distortion (quality) measure for planar meshes to meshes on parameterized surfaces. The resulting distortion (quality) measure is expressed in terms of the parametric coordinates of the nodes. This extended distortion (quality) measure can be used to check the quality and validity of both triangle and quadrilateral surface meshes. We also apply it to simultaneously smooth and untangle surface meshes by minimizing the extended distortion measure. The minimization is performed in terms of the parametric coordinates of the nodes and therefore, the nodes always lie on the surface. Finally, we include several examples to illustrate the applicability of the proposed technique. Specifically, we extend several Jacobian-based measures, and we us them to smooth and untangle triangle and quadrilateral meshes on CAD surfaces.

    Postprint (author’s final draft)

  • Meshing Maestro Poster Award 2012

     Gargallo Peiró, Abel; Sarrate Ramos, Jose
    Award or recognition

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  • Defining quality measures for high-order planar triangles and curved mesh generation

     Roca Navarro, Xevi; Gargallo Peiró, Abel; Sarrate Ramos, Jose
    International Meshing Roundtable
    Presentation's date: 2011-10-23
    Presentation of work at congresses

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  • Unstructured hexaedral mesh generation for exteroir domains by the receding front method

     Ruiz Girones, Eloi; Roca Navarro, Francisco Javier; Sarrate Ramos, Jose
    Congresso de Métodos Numéricos em Engenharia
    Presentation's date: 2011-06-14
    Presentation of work at congresses

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  • Automatic Hexahedral meshing algorithms: From structured to unstructured meshes

     Ruiz Girones, Eloi
    Defense's date: 2011-02-28
    Department of Applied Mathematics III, Universitat Politècnica de Catalunya
    Theses

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  • Automatic hexaedral meshing algorithms: from structured to unstructured meshes

     Ruiz Girones, Eloi
    Defense's date: 2011-02-28
    Department of Applied Mathematics III, Universitat Politècnica de Catalunya
    Theses

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  • Q-00024

     Sarrate Ramos, Jose; Diez Mejia, Pedro
    Participation in a competitive project

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  • Using a computational domain and a three-stage node location procedure for multi-sweeping algorithms

     Ruiz Girones, Eloi; Roca Navarro, Francisco Javier; Sarrate Ramos, Jose
    Advances in engineering software
    Date of publication: 2011
    Journal article

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  • The receding front method applied to hexahedral mesh generation of exterior domains

     Ruiz Girones, Eloi; Roca Navarro, Francisco Javier; Sarrate Ramos, Jose
    Engineering with computers
    Date of publication: 2011-11-30
    Journal article

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  • Receding front method: a new approach applied to generate hexahedral meshes of outer domains

     Roca Navarro, Francisco Javier; Ruiz Girones, Eloi; Sarrate Ramos, Jose
    International Meshing Roundtable
    Presentation of work at congresses

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    Two of the most successful methods to generate unstructured hexahedral meshes are the grid-based methods and the advancing front methods. On the one hand, the grid-based methods generate high quality elements in the inner part of the domain using an inside-outside approach. On the other hand, advancing front methods generate high quality hexahedra near the boundary using an outside-inside approach. In this paper we propose the receding front method, an original approach that combines the advantages of both methodologies: we use an inside-outside mesh generation approach by means of a reversed front advance. We apply this approach to mesh outer domains. To reproduce the shape of the boundaries, we first precompute the mesh fronts by combining two solutions of the Eikonal equation on a tetrahedral reference mesh. Then, to generate high quality elements, we expand the quadrilateral surface mesh of the inner body towards the unmeshed external boundary using the pre-computed fronts as a guide. Further research is under way in order to apply the proposed method to more complicated geometries.

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    Automatic generation of hexahedral meshes for volumes with non-planar surfaces using the multi-sweeping method  Open access

     Ruiz Girones, Eloi; Roca Navarro, Francisco Javier; Sarrate Ramos, Jose
    International Conference on Engineering Computational Technology
    Presentation's date: 2010
    Presentation of work at congresses

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    One of the most used algorithms to generate hexahedral meshes for extrusion volumes is the multi-sweeping method. The algorithm decomposes the geometry into many-to-one sub-volumes and then meshes each sub-volume separately. However, the quality of the final mesh depends on the decomposition process. First, the location of inner nodes created during the decomposition process may induce bad quality elements. To avoid this drawback, we propose a three-stage decomposition process to locate those nodes. Second, the imprinting process is not robust when dealing with non-planar surfaces. For this reason, we introduce the new concept of the computational domain. The computational domain is a planar representation of the levels of the geometry. In this way, we improve the operations needed to perform imprints.

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    Generation of structured hexahedral meshes in volumes with holes  Open access

     Ruiz Girones, Eloi; Sarrate Ramos, Jose
    Finite elements in analysis and design
    Date of publication: 2010-10
    Journal article

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    The submapping method is one of the most used techniques to generate structured hexahedral meshes. This method splits the geometry into pieces logically equivalent to an hexahedron. Then, it meshes each patch keeping the mesh compatibility between pieces by solving an integer linear problem. The quality of the final discretization is governed by the objective function that defines the linear problem. Thus, in this work we propose a new objective function that better distributes the number of intervals among the edges of the geometry. In addition, special procedures have to be developed in order to apply the submapping method to volumes with holes. This article also presents two original contributions to efficiently mesh geometries that contain holes. Finally, it presents several numerical examples that show the applicability of the developed algorithms.

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    Generation of structured meshes in multiply connected surfaces using submapping  Open access

     Ruiz Girones, Eloi; Sarrate Ramos, Jose
    Advances in engineering software
    Date of publication: 2010-02
    Journal article

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    The submapping method is one of the most widely used techniques to generate structured quadrilateral meshes. This method splits the geometry into pieces logically equivalent to a quadrilateral. Then, it meshes each piece keeping the mesh compatibility between them by solving an integer linear problem. The main limitation of submapping algorithms is that it can only be applied to geometries in which the angle between two consecutive edges is, approximately, an integer multiple of p=2. In addition, special procedures are required in order to apply it to multiply connected domains. This article presents two original modifications to mitigate these shortcomings. Finally, it presents several numerical examples that show the applicability of the developed algorithms.

    Postprint (author’s final draft)

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    An automatic and general least-squares projection procedure for sweep meshing  Open access

     Roca Navarro, Francisco Javier; Sarrate Ramos, Jose
    Engineering with computers
    Date of publication: 2010-01-07
    Journal article

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    In this paper, we present a new and automatic node projection algorithm to generate hexahedral meshes in extrusion geometries. It is designed to preserve the shape of the cap surfaces in the inner layers of a sweeping mesh. The algorithm is based on least-squares approximation of affine mappings. We report that the functionals that have been traditionally used to compute the affine mapping generate four undesired effects on the inner layers of nodes. Namely, the flattening, skewing, offset scaling, and flipping of the inner layer meshes. To overcome these drawbacks we first analyze several properties of a new functional that depends on two vector parameters. Second, we introduce the concept of the pseudo-area and pseudo-normal vectors defined by a loop of nodes. In addition, we prove several geometrical properties of these vectors. Third, based on the properties of the new functional and on the definition of the pseudo-normal vector, we detail a new projection algorithm that automatically selects the functional vector parameters. The aim of this paper is to provide the implementation details to developers, although we also present the background of the algorithm. Finally, several mesh examples are discussed to assess the properties of the proposed algorithm.

  • A new least-squares approximation of affine mappings for sweep algorithms.

     Roca Navarro, Francisco Javier; Sarrate Ramos, Jose; Huerta Cerezuela, Antonio
    Engineering with computers
    Date of publication: 2010
    Journal article

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    Local dual contributions: representing dual surfaces for block meshing  Open access

     Roca Navarro, Francisco Javier; Sarrate Ramos, Jose
    International journal for numerical methods in engineering
    Date of publication: 2010-08-06
    Journal article

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    In this work we present a tool based on the new concept of local dual contributions for directly representing the topology and the approximated geometry of the dual of a block mesh. This tool allows us to obtain a valid block decomposition of a given geometry without a previous discretization of its boundary. Specifically, our tool is composed of a hierarchical scheme and a set of matching rules that explicitly insert descriptions of dual surfaces and handle their intersections. That is, the proposed tool generates a dual of the block mesh with intersections of the proper multiplicity without gaps and which respects the boundary features of the domain. Finally, we present several examples that illustrate the applicability of the tool.

  • Stabilized Finite Element Approximation of the Incompressible MHD Equations  Open access

     HERNÁNDEZ SILVA, NOEL
    Defense's date: 2010-07-12
    Department of Strength of Materials and Structural Engineering, Universitat Politècnica de Catalunya
    Theses

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    No es frecuente encontrar un campo donde dos ramas principales de la Física estén involucradas. La Magnetohidrodinámica es uno de tales campos debido a que involucra a la Mecánica de Fluidos y al Electromagnetismo. Aun cuando puede parecer que esas dos ramas de la Física tienen poco en común, comparten similitudes en las ecuaciones que gobiernan los fenómenos involucrados en ellas. Las ecuaciones de Navier-Stokes y las ecuaciones de Maxwell, ambas en la raíz de la Magnetohidrodinámica, tienen una condición de divergencia nula y es esta condición de divergencia nula sobre la velocidad del fluido y el campo magnético lo que origina algunos de los problemas numéricos que surgen en la modelación de los fenómenos donde el flujo de fluidos y los campos magnéticos están acoplados.El principal objetivo de este trabajo es desarrollar un algoritmo eficiente para la resolución mediante elementos finitos de las ecuaciones de la Magnetohidrodinámica de fluidos incompresibles.Para lograr esta meta, los conceptos básicos y las características de la Magnetohidrodinámica se presentan en una breve introducción informal.A continuación, se da una revisión completa de las ecuaciones de gobierno de la Magnetohidrodinámica, comenzando con las ecuaciones de Navier-Stokes y las ecuaciones de Maxwell. Se discute la aproximación que da origen a las ecuaciones de la Magnetohidrodinámica y finalmente se presentan las ecuaciones de la Magnetohidrodinámica.Una vez que las ecuaciones de gobierno de la Magnetohidrodinámica han sido definidas, se presentan los esquemas numéricos desarrollados, empezando con la linealización de las ecuaciones originales, la formulación estabilizada y finalmente el esquema numérico propuesto. En esta etapa se presenta una prueba de convergencia.Finalmente, se presentan los ejemplos numéricos desarrollados durante este trabajo.Estos ejemplos pueden dividirse en dos grupos: ejemplos numéricos de comparación y ejemplos de internes tecnológico. Dentro del primer grupo están incluidas simulaciones del flujo de Hartmann y del flujo sobre un escalón. El segundo grupo incluye simulaciones del flujo en una tobera de inyección de colada continua y el proceso Czochralski de crecimiento de cristales.

    It is not frequent to find a field where two major branches of Physics are involved. Magnetohydrodynamics is one of such fields because it involves Fluid Mechanics and Electromagnetism. Although those two branches of Physics can seem to have little in common, they share similarities in the equations that govern the phenomena involved. The Navier-Stokes equations and the Maxwell equations, both at the root of Magnetohydrodynamics, have a divergence free condition and it is this divergence free condition over the velocity of the fluid and the magnetic field what gives origin to some of the numerical problems that appear when approximating the equations that model the phenomena where fluids flow and magnetic fields are coupled.The main objective of this work is to develop an efficient finite element algorithm for the incompressible Magnetohydrodynamics equations.In order to achieve this goal the basic concepts and characteristics of Magnetohydrodynamics are presented in a brief and informal introduction.Next, a full review of the governing equations of Magnetohydrodynamics is given, staring from the Navier-Stokes equations and the Maxwell equations. The MHD approximation is discussed at this stage and the proper Magnetohydrodynamics equations for incompressible fluid are reviewed.Once the governing equations have been defined, the numerical schemes developed are presented, starting with the linearization of the original equations, the stabilization formulations and finally the numerical scheme proposed. A convergence test is shown at this stage.Finally, the numerical examples performed while this work was developed are presented. These examples can be divided in two groups: numerical benchmarks and numerical examples of technological interest. In the first group, the numerical simulations for the Hartmann flow and the flow over a step are included. The second group includes the simulation of the clogging in a continuous casting nozzle and Czochralski crystal growth process.

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    A new procedure to compute imprints in multi-sweeping algorithms  Open access

     Ruiz Girones, Eloi; Roca Navarro, Francisco Javier; Sarrate Ramos, Jose
    International Meshing Roundtable
    Presentation's date: 2009-10-26
    Presentation of work at congresses

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    One of the most widely used algorithms to generate hexahedral meshes in extrusion volumes with several source and target surfaces is the multi-sweeping method. However, the multi-sweeping method is highly dependent on the final location of the nodes created during the decomposition process. Moreover, inaccurate location of inner nodes may generate erroneous imprints of the geometry surfaces such that a final mesh could not be generated. In this work, we present a new procedure to decompose the geometry in many-to-one sweepable volumes. The decomposition is based on a least-squares approximation of affine mappings defined between the loops of nodes that bound the sweep levels. In addition, we introduce the concept of computational domain, in which every sweep level is planar. We use this planar representation for two purposes. On the one hand, we use it to perform all the imprints between surfaces. Since the computational domain is planar, the robustness of the imprinting process is increased. On the other hand, the computational domain is also used to compute the projection onto source surfaces. Finally, the location of the inner nodes created during the decomposition process is computed by averaging the locations computed projecting from target and source surfaces.

  • High-order discontinuous Galerkin methods for incompressible flows  Open access

     de Villardi de Montlaur, Adeline
    Defense's date: 2009-09-22
    Universitat Politècnica de Catalunya
    Theses

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    Aquesta tesi doctoral proposa formulacions de Galerkin discontinu (DG) d'alt ordre per fluxos viscosos incompressibles. Es desenvolupa un nou mètode de DG amb penalti interior (IPM-DG), que condueix a una forma feble simètrica i coerciva pel terme de difusió, i que permet assolir una aproximació espacial d'alt ordre. Aquest mètode s'aplica per resoldre les equacions de Stokes i Navier-Stokes. L'espai d'aproximació de la velocitat es descompon dins de cada element en una part solenoidal i una altra irrotacional, de manera que es pot dividir la forma dèbil IPM-DG en dos problemes desacoblats. El primer permet el càlcul de les velocitats i de les pressions híbrides, mentre que el segon calcula les pressions en l'interior dels elements. Aquest desacoblament permet una reducció important del número de graus de llibertat tant per velocitat com per pressió. S'introdueix també un paràmetre extra de penalti resultant en una formulació DG alternativa per calcular les velocitats solenoidales, on les pressions no apareixen. Les pressions es poden calcular com un post-procés de la solució de les velocitats. Es contemplen altres formulacions DG, com per exemple el mètode Compact Discontinuous Galerkin, i es comparen al mètode IPM-DG. Es proposen mètodes implícits de Runge-Kutta d'alt ordre per problemes transitoris incompressibles, permetent obtenir esquemes incondicionalment estables i amb alt ordre de precisió temporal. Les equacions de Navier-Stokes incompressibles transitòries s'interpreten com un sistema de Equacions Algebraiques Diferencials, és a dir, un sistema d'equacions diferencials ordinàries corresponent a la equació de conservació del moment, més les restriccions algebraiques corresponent a la condició d'incompressibilitat. Mitjançant exemples numèrics es mostra l'aplicabilitat de les metodologies proposades i es comparen la seva eficiència i precisió.

    This PhD thesis proposes divergence-free Discontinuous Galerkin formulations providing high orders of accuracy for incompressible viscous flows. A new Interior Penalty Discontinuous Galerkin (IPM-DG) formulation is developed, leading to a symmetric and coercive bilinear weak form for the diffusion term, and achieving high-order spatial approximations. It is applied to the solution of the Stokes and Navier-Stokes equations. The velocity approximation space is decomposed in every element into a solenoidal part and an irrotational part. This allows to split the IPM weak form in two uncoupled problems. The first one solves for velocity and hybrid pressure, and the second one allows the evaluation of pressures in the interior of the elements. This results in an important reduction of the total number of degrees of freedom for both velocity and pressure. The introduction of an extra penalty parameter leads to an alternative DG formulation for the computation of solenoidal velocities with no presence of pressure terms. Pressure can then be computed as a post-process of the velocity solution. Other DG formulations, such as the Compact Discontinuous Galerkin method, are contemplated and compared to IPM-DG. High-order Implicit Runge-Kutta methods are then proposed to solve transient incompressible problems, allowing to obtain unconditionally stable schemes with high orders of accuracy in time. For this purpose, the unsteady incompressible Navier-Stokes equations are interpreted as a system of Differential Algebraic Equations, that is, a system of ordinary differential equations corresponding to the conservation of momentum equation, plus algebraic constraints corresponding to the incompressibility condition. Numerical examples demonstrate the applicability of the proposed methodologies and compare their efficiency and accuracy.

  • Paving the path towards automatic hexahedral mesh generation  Open access

     Roca Navarro, Francisco Javier
    Defense's date: 2009-07-23
    Department of Applied Mathematics III, Universitat Politècnica de Catalunya
    Theses

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    Esta tesis versa sobre el desarrollo de las tecnologías para la generación de mallas de hexaedros. El proceso de generar una malla de hexaedros no es automático y su generación requiere varias horas te trabajo de un ingeniero especializado. Por lo tanto, es importante desarrollar herramientas que faciliten dicho proceso de generación. Con este fin, se presenta y desarrolla un método de proyección de mallas, una técnica de sweeping o barrido, un algoritmo para la obtención de mallas por bloques, y un entorno de generación de mallas. Las implementaciones más competitivas del método de sweeping utilizan técnicas de proyección de mallas basadas en métodos afines. Los métodos afines más habituales presentan varios problemas relacionados con la obtención de sistemas de ecuaciones normales de rango deficiente. Para solucionar dichos problemas se presenta y analiza un nuevo método afín que depende de dos parámetros vectoriales. Además, se detalla un procedimiento automático para la selección de dichos vectores. El método de proyección resultante preserva la forma de las mallas proyectadas. Esta proyección es incorporada también en una nueva herramienta de sweeping. Dicha herramienta genera capas de nodos internos que respetan la curvatura de las superficies inicial y final. La herramienta de sweeping es capaz de mallar geometrías de extrusión definidas por trayectorias curvas, secciones no constantes a lo largo del eje de sweeping, y superficies inicial y final con diferente forma y curvatura.En las últimas décadas se han propuesto varios ataques para la generación automática de mallas de hexahedros. Sin embargo, todavía no existe un algoritmo rápido y robusto que genere automáticamente mallas de hexaedros de alta calidad. Se propone un nuevo ataque para la generación de mallas por bloques mediante la representación de la geometría y la topología del dual de una malla de hexaedros. En dicho ataque, primero se genera una malla grosera de tetraedros. Después, varió polígonos planos se añaden al interior de los elementos de la malla grosera inicial. Dichos polígonos se denotan como contribuciones duales locales y representan una versión discreta del dual de una malla de hexaedros. En el último paso, la malla por bloques se obtiene como el dual de la representación del dual generada. El algoritmo de generación de mallas por bloques es aplicado a geometrías que presentan diferentes características geométricas como son superficies planas, superficies curvas, configuraciones delgadas, agujeros, y vértices con valencia mayor que tres.Las mallas se generan habitualmente con la ayuda de entornos interactivos que integran una interfaz CAD y varios algoritmos de generación de mallas. Se presenta un nuevo entorno de generación de mallas especializado en la generación de cuadriláteros y hexaedros. Este entorno proporciona la tecnología necesaria para implementar les técnicas de generación de mallas de hexaedros presentadas en esta tesis.

    This thesis deals with the development of hexahedral mesh generation technology. The process of generating hexahedral meshes is not fully automatic and it is a time consuming task. Therefore, it is important to develop tools that facilitate the generation of hexahedral meshes. To this end, a mesh projection method, a sweeping technique, a block-meshing algorithm, and an interactive mesh generation environment are presented and developed. Competitive implementations of the sweeping method use mesh projection techniques based on affine methods. Standard affine methods have several drawbacks related to the statement of rank deficient sets of normal equations. To overcome these drawbacks a new affine method that depends on two vector parameters is presented and analyzed. Moreover, an automatic procedure that selects these two vector parameters is detailed. The resulting projection procedure preserves the shape of projected meshes. Then, this procedure is incorporated in a new sweeping tool. This tool generates inner layers of nodes that preserve the curvature of the cap surfaces. The sweeping tool is able to mesh extrusion geometries defined by non-linear sweeping trajectories, non-constant cross sections along the sweep axis, non-parallel cap surfaces, and cap surfaces with different shape and curvature. In the last decades, several general-purpose approaches to generate automatically hexahedral meshes have been proposed. However, a fast and robust algorithm that automatically generates high-quality hexahedral meshes is not available. A novel approach for block meshing by representing the geometry and the topology of a hexahedral mesh is presented. The block-meshing algorithm first generates an initial coarse mesh of tetrahedral elements. Second, several planar polygons are added inside the elements of the initial coarse mesh. These polygons are referred as local dual contributions and represent a discrete version of the dual of a hexahedral mesh. Finally, the dual representation is dualized to obtain the final block mesh. The block-meshing algorithm is applied to mesh geometries that present different geometrical characteristics such as planar surfaces, curved surfaces, thin configurations, holes, and vertices with valence greater than three.Meshes are usually generated with the help of interactive environments that integrate a CAD interface and several meshing algorithms. An overview of a new mesh generation environment focused in quadrilateral and hexahedral mesh generation is presented. This environment provides the technology required to implement the hexahedral meshing techniques presented in this thesis.

  • MÈTODES NUMÈRICS EN CIÈNCIES APLICADES I ENGINYERIA

     Roca Navarro, Francisco Javier; Giorgiani, Giorgio; Zlotnik, Sergio; Fernandez Mendez, Sonia; Rodriguez Ferran, Antonio; Muñoz Romero, Jose Javier; Arias Vicente, Irene; de Villardi de Montlaur, Adeline; Sarrate Ramos, Jose; Diez Mejia, Pedro; Arroyo Balaguer, Marino; Sevilla Cardenas, Ruben; Parés Mariné, Núria; Casoni Rero, Eva; Ruiz Girones, Eloi; Modesto Galende, David; Millan, Raul Daniel; Abdollahi Hosnijeh, Amir; Steffens, Lindaura Maria; Discacciati, Marco; Shen, Yongxing; Rahimi Lenji, Mohammad; Tamayo Mas, Elena; Diaz Cereceda, Cristina; Prat Robles, David; Verdugo Rojano, Francesc; Zhang, Kuan; Estela Carbonell, M. Rosa; Peco Regales, Christian; Huerta Cerezuela, Antonio
    Participation in a competitive project

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    Discretización de superficies múltiplemente conexas mediante submapping  Open access

     Ruiz Girones, Eloi; Sarrate Ramos, Jose
    Revista internacional de métodos numéricos para cálculo y diseño en ingeniería
    Date of publication: 2008-09
    Journal article

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    Una de las técnicas más utilizadas para generar mallas estructuradas de cuadriláteros es el método de submapping. Este método descompone la geometría en piezas lógicamente equivalentes a un cuadrilátero y después malla cada una de ellas por separado manteniendo la compatibilidad de la malla mediante la resolución de un problema lineal entero. El algoritmo de submapping tiene dos limitaciones principales. La primera de ellas es que sólo se puede aplicar en geometrías tales que el ángulo entre dos aristas consecutivas es, aproximadamente, un múltiplo entero de π/2. La segunda limitación es que la geometría tiene que ser simplemente conexa. Con el objetivo de mitigar estas restricciones, en este artículo se presentan dos modificaciones originales que permiten reducir el efecto de dichas limitaciones. Finalmente, se presentan diversos ejemplos numéricos que ponen de manifiesto la robustez y la aplicabilidad de los algoritmos desarrollados.

  • Local dual contributions on simplices: a tool for block meshing

     Roca, X.; Sarrate Ramos, Jose
    International Meshing Roundtable
    Presentation's date: 2008-10-13
    Presentation of work at congresses

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  • Automatic generation of structured hexahedral meshes for non-simply connected geometries using submapping

     Sarrate Ramos, Jose; Ruiz Gironés, Eloi
    International Conference on Engineering Computational Technology
    Presentation's date: 2008-09-02
    Presentation of work at congresses

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  • Minimization of the distortion of quadrilateral and hexahedral meshes

     Sarrate Ramos, Jose; COLL, A
    Revista internacional de métodos numéricos para cálculo y diseño en ingeniería
    Date of publication: 2007-01
    Journal article

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  • Automatic Generation of Structured Meshes Using Linear Programming and Transfinite Interpolation Artículo

     Ruiz, E; Sarrate Ramos, Jose
    Congresso de Métodos Numéricos em Engenharia
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  • Aproximacion Mediante Mínimos Cuadrados de Proyecciones Afines para la Generacion de Hexaedros en Algoritmos de Barrido

     Sarrate Ramos, Jose; Roca Navarro, Francisco Javier
    Congresso de Métodos Numéricos em Engenharia
    Presentation's date: 2007-06-13
    Presentation of work at congresses

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  • Fomento de las acciones de innovación pedagógica en la Ingeniería Civil

     Sarrate Ramos, Jose
    International Conference on Adaptive Modeling and Simulation
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  • Diseny Workpack per a una Casa d'Acer

     Huerta Cerezuela, Antonio; Rodriguez Ferran, Antonio; Diez Mejia, Pedro; Sarrate Ramos, Jose
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  • Modelització numérica d'estructures e infraestructures: disseny, durabilitat y estats límit.

     Huerta Cerezuela, Antonio; Sarrate Ramos, Jose
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  • Modelización numérica de flujos, solidos y estructuras para aplicaciones industriales

     de Villardi de Montlaur, Adeline; Diez Mejia, Pedro; Estela Carbonell, M. Rosa; Arias Vicente, Irene; Fernandez Mendez, Sonia; Sarrate Ramos, Jose; Vidal Segui, Yolanda; Parés Mariné, Núria; Sevilla Cardenas, Ruben; Casoni Rero, Eva
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  • A Graphical Modeling and Mesh Generation Environment for Simulations Based on Boundary Representation Data

     Roca Navarro, Francisco Javier; Sarrate Ramos, Jose; Ruiz-Gironés, E
    Congresso de Métodos Numéricos em Engenharia
    Presentation's date: 2007-06-13
    Presentation of work at congresses

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  • Developing a graphical modeling and mesh generation evironment using open sourde software

     Sarrate Ramos, Jose; Roca Navarro, Francisco Javier; Ruiz-Gironés, E
    International Conference on Adaptive Modeling and Simulation
    Presentation's date: 2007-10-22
    Presentation of work at congresses

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  • Access to the full text
    Minimización de la distorsión de mallas formadas por cuadriláteros o hexaedros  Open access

     Sarrate Ramos, Jose; Coll, Abel
    Revista internacional de métodos numéricos para cálculo y diseño en ingeniería
    Date of publication: 2007
    Journal article

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    En este artículo se presenta un algoritmo para la minimización de la medida de la distorsión definida por Oddy para una malla formada por cuadriláteros o hexaedros. Aunque dicha medida ha sido ampliamente utilizada, su definición original presenta varias propiedades que limitan su utilización en un algoritmo de minimización. Por ejemplo, sólo es válida para cuadriláteros o hexaedros convexos y proporciona un valor infinito de la distorsión en un cuadrilátero en el que tres vértices están alineados. Con el fin de superar estas limitaciones, en este trabajo primero se deduce una interpretación geométrica de la definición original de la medida de la distorsión. Además se demuestra que dicha interpretación es válida tanto para cuadriláteros como para hexaedros. Seguidamente y basándose en dicha interpretación, se desarrolla una medida de la distorsión para cuadriláteros y hexaedros no convexos. Finalmente, se presenta un algoritmo para la minimización de la nueva medida de la distorsión de la malla basado en el método de Newton-Raphson. Es importante resaltar que ambas definiciones coinciden cerca de la solución óptima. Así mismo, se presentan varios ejemplos que confirman la eficiencia del algoritmo desarrollado.

  • An Automatic and General Least-Squares Projection for Sweep Meshing

     Roca Navarro, Francisco Javier; Sarrate Ramos, Jose
    International Meshing Roundtable
    Presentation's date: 2006-09-17
    Presentation of work at congresses

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  • A Comparative Analysis of Sweeping Schemes Based on Affine Mapping Projections

     Roca Navarro, Francisco Javier; Sarrate Ramos, Jose
    International Conference on Engineering Computational Technology
    Presentation's date: 2006-09-12
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  • Generación y adaptación de mallas

     Sarrate Ramos, Jose
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  • Verificación y validación de modelos numéricos en medio poroso

     Arias Vicente, Irene; Diez Mejia, Pedro; Arroyo Balaguer, Marino; Sarrate Ramos, Jose
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  • Generación y adaptación de mallas

     Sarrate Ramos, Jose; Diez Mejia, Pedro
    Participation in a competitive project

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  • Ajudes per a la financiació de grups d'investigació de Catalunya. (Grup consolidat d'investigació en el marc del Plan d'Investigació e Innovació de Catalunya 2005-2008)

     Sala Lardies, Esther; Huerta Cerezuela, Antonio; Rodriguez Ferran, Antonio; Arias Vicente, Irene; Perez Foguet, Agusti; Arroyo Balaguer, Marino; Fernandez Mendez, Sonia; Sarrate Ramos, Jose
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  • LIGHTFRAME. Desenvolupament de prototipus d'estructura metálica amb propietats acústiques i de vibració millorades (2005-2007)

     Huerta Cerezuela, Antonio; Rodriguez Ferran, Antonio; Diez Mejia, Pedro; Perez Foguet, Agusti; Fernandez Mendez, Sonia; Sarrate Ramos, Jose
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  • Access to the full text
    Mesh projection between parametric surfaces  Open access

     Roca Navarro, Francisco Javier; Sarrate Ramos, Jose; Huerta Cerezuela, Antonio
    Communications in numerical methods in engineering
    Date of publication: 2006-06
    Journal article

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    This paper presents a new algorithm to map a given mesh over a source surface onto a target surface. This projection is determined by means of a least-squares approximation of a transformation defined between the loops of boundary nodes of the cap surfaces in the parametric spaces. Once the new mesh is obtained on the parametric space of the target surface, it is mapped to the target surface according to its parameterization. Therefore, in contrast with the usual techniques, the developed algorithm does not require solving any root finding problem to ensure that the projected nodes are on the target surface. Finally, this projection algorithm is extended to three-dimensional cases and included in a sweep meshing tool in order to generate the inner layers of elements in the physical space.

    Postprint (author’s final draft)

  • A new least-squares approximation of affine mappings for sweep algorithms

     Roca Navarro, Francisco Javier; Sarrate Ramos, Jose; Huerta Cerezuela, Antonio
    International Meshing Roundtable
    Presentation of work at congresses

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  • Determination of affine mesh projections via functional minimization

     Roca Navarro, Francisco Javier; Sarrate Ramos, Jose
    Workshop on Numerical Methods in Applied Science and Engineering
    Presentation's date: 2005-01-18
    Presentation of work at congresses

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  • Generación de Mallas de cuadriláreros sobre superficies paramétricas

     Roca Navarro, Francisco Javier; Sarrate Ramos, Jose; Huerta Cerezuela, Antonio
    Congreso de Métodos Numéricos en Ingeniería
    Presentation's date: 2005-07-04
    Presentation of work at congresses

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