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  • A shallow water model by finite point method

     Bouchart, Chinapat; Kanok-Nukulchai, Worsak; Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio
    International journal of computational methods
    Date of publication: 2014-02-01
    Journal article

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    In this paper, "finite point method" (FPM) is presented for modeling 2D shallow water flow problem. The method is based on the use of a weighted least-square approximation procedure, incorporating QR factorization and an iterative adjustment of local approximation parameters. The stabilization of the convective term in this present work is derived from the approximate Riemann solver proposed by Roe. The present method is shown to produce competitive accuracy in the comparisons with the analytical solutions and the well-known Galerkin characteristic-based split (CBS) algorithm.

  • Development and applications of the Finite Point Method to compressible aerodynamics problems  Open access

     Ortega, Enrique
    Defense's date: 2014-05-12
    Universitat Politècnica de Catalunya
    Theses

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    En este trabajo se aborda el desarrollo del Método de Puntos Finitos (MPF) y su aplicación a problemas de aerodinámica de flujos compresibles. El objetivo principal es investigar el potencial de la técnica sin malla para la solución de problemas prácticos, lo cual constituye una de las limitaciones más importantes de los métodos sin malla.En primer lugar se estudia la aproximación espacial en el MPF, haciendo hincapié en aquéllos aspectos que pueden ser mejorados para incrementar la robustez y exactitud de la metodología. Se determinan rangos adecuados para el ajuste de los parámetros de la aproximación y su comportamiento en situaciones prácticas. Se propone además un procedimiento de ajuste automático de estos parámetros a fin de simplificar la aplicación del método y reducir la dependencia de factores como el tipo de problema y la intervención del usuario, sin afectar la flexibilidad de la técnica sin malla.A continuación se aborda el esquema de solución de las ecuaciones del flujo. La discretización de las mismas se lleva a cabo siguiendo métodos estándar, pero aprovechando las características de la técnica sin malla. Con el objetivo de abordar problemas prácticos, se pone énfasis en la robustez y eficiencia de la implementación numérica (se propone además una simplificación del procedimiento de solución). El comportamiento del esquema se estudia en detalle para evaluar su potencial y se analiza su exactitud, coste computacional y escalabilidad, todo ello en comparación con un método convencional basado en Elementos Finitos.Finalmente se presentan distintas aplicaciones y extensiones de la metodología desarrollada. Los ejemplos numéricos pretenden demostrar las capacidades del método y también aprovechar las ventajas de la metodología sin malla en áreas en que la misma puede ser de especial interés. Los problemas tratados incluyen, entre otras características, el refinamiento automático de la discretización, la presencia de fronteras móviles e interacción fluido-estructura, como así también una aplicación preliminar a flujos compresibles de alto número de Reynolds. Los resultados obtenidos muestran una exactitud satisfactoria. Además, en comparación con una técnica similar basada en Elementos Finitos, demuestran ser competitivos en términos del coste computacional. Esto indica que las ventajas de la metodología sin malla pueden ser explotadas con eficiencia, lo cual constituye un buen punto de partida para el desarrollo de ulteriores aplicaciones.

    This work deals with the development and application of the Finite Point Method (FPM) to compressible aerodynamics problems. The research focuses mainly on investigating the capabilities of the meshless technique to address practical problems, one of the most outstanding issues in meshless methods. The FPM spatial approximation is studied firstly, with emphasis on aspects of the methodology that can be improved to increase its robustness and accuracy. Suitable ranges for setting the relevant approximation parameters and the performance likely to be attained in practice are determined. An automatic procedure to adjust the approximation parameters is also proposed to simplify the application of the method, reducing problem- and user-dependence without affecting the flexibility of the meshless technique. The discretization of the flow equations is carried out following wellestablished approaches, but drawing on the meshless character of the methodology. In order to meet the requirements of practical applications, the procedures are designed and implemented placing emphasis on robustness and efficiency (a simplification of the basic FPM technique is proposed to this end). The flow solver is based on an upwind spatial discretization of the convective fluxes (using the approximate Riemann solver of Roe) and an explicit time integration scheme. Two additional artificial diffusion schemes are also proposed to suit those cases of study in which computational cost is a major concern. The performance of the flow solver is evaluated in order to determine the potential of the meshless approach. The accuracy, computational cost and parallel scalability of the method are studied in comparison with a conventional FEM-based technique. Finally, practical applications and extensions of the flow solution scheme are presented. The examples provided are intended not only to show the capabilities of the FPM, but also to exploit meshless advantages. Automatic hadaptive procedures, moving domain and fluid-structure interaction problems, as well as a preliminary approach to solve high-Reynolds viscous flows, are a sample of the topics explored. All in all, the results obtained are satisfactorily accurate and competitive in terms of computational cost (if compared with a similar mesh-based implementation). This indicates that meshless advantages can be exploited with efficiency and constitutes a good starting point towards more challenging applications.

    En este trabajo se aborda el desarrollo del Método de Puntos Finitos (MPF) y su aplicación a problemas de aerodinámica de flujos compresibles. El objetivo principal es investigar el potencial de la técnica sin malla para la solución de problemas prácticos, lo cual constituye una de las limitaciones más importantes de los métodos sin malla. En primer lugar se estudia la aproximación espacial en el MPF, haciendo hincapié en aquéllos aspectos que pueden ser mejorados para incrementar la robustez y exactitud de la metodología. Se determinan rangos adecuados para el ajuste de los parámetros de la aproximación y su comportamiento en situaciones prácticas. Se propone además un procedimiento de ajuste automático de estos parámetros a fin de simplificar la aplicación del método y reducir la dependencia de factores como el tipo de problema y la intervención del usuario, sin afectar la flexibilidad de la técnica sin malla. A continuación se aborda el esquema de solución de las ecuaciones del flujo. La discretización de las mismas se lleva a cabo siguiendo métodos estándar, pero aprovechando las características de la técnica sin malla. Con el objetivo de abordar problemas prácticos, se pone énfasis en la robustez y eficiencia de la implementación numérica (se propone además una simplificación del procedimiento de solución). El comportamiento del esquema se estudia en detalle para evaluar su potencial y se analiza su exactitud, coste computacional y escalabilidad, todo ello en comparación con un método convencional basado en Elementos Finitos. Finalmente se presentan distintas aplicaciones y extensiones de la metodología desarrollada. Los ejemplos numéricos pretenden demostrar las capacidades del método y también aprovechar las ventajas de la metodología sin malla en áreas en que la misma puede ser de especial interés. Los problemas tratados incluyen, entre otras características, el refinamiento automático de la discretización, la presencia de fronteras móviles e interacción fluido-estructura, como así también una aplicación preliminar a flujos compresibles de alto número de Reynolds. Los resultados obtenidos muestran una exactitud satisfactoria. Además, en comparación con una técnica similar basada en Elementos Finitos, demuestran ser competitivos en términos del coste computacional. Esto indica que las ventajas de la metodología sin malla pueden ser explotadas con eficiencia, lo cual constituye un buen punto de partida para el desarrollo de ulteriores aplicaciones.

  • Comparative accuracy and performance assessment of the finite point method in compressible flow problems

     Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio; Idelsohn Barg, Sergio Rodolfo; Flores Le Roux, Roberto Maurice
    Computers and fluids
    Date of publication: 2014-01-20
    Journal article

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    A comparative assessment of the Finite Point Method (FPM) is presented. Using a wing-fuselage configuration under transonic inviscid flow conditions as reference test case, the performance of the FPM flow solver is compared with an equivalent edge-based Finite Element (FEM) implementation. Efficiency issues have discouraged practical application of meshless methods in the past. Thus, a simplification of the basic FPM technique is proposed in order to reduce the performance gap with respect to classical grid-based algorithms. A comparative evaluation of the accuracy, computational cost and parallel performance of the meshless implementation is carried out with the objective to assess the level of maturity of the technique and identify improvements still required to tackle practical applications. The results obtained show accuracy and performance of the core algorithm comparable to a conventional FEM implementation, thus removing a major obstacle for further developments of the FPM.

  • Application of the finite point method to high- Reynolds number compressible flow problems

     Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio; Idelsohn Barg, Sergio Rodolfo; Flores Le Roux, Roberto Maurice
    International journal for numerical methods in fluids
    Date of publication: 2014-04-10
    Journal article

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    In this work, the finite point method is applied to the solution of high-Reynolds compressible viscous flows. The aim is to explore this important field of applications focusing on two main aspects: the easiness and automation of the meshless discretization of viscous layers and the construction of a robust numerical approximation in the highly stretched clouds of points resulting in such domain areas. The flow solution scheme adopts an upwind-biased scheme to solve the averaged Navier-Stokes equations in conjunction with an algebraic turbulence model. The numerical applications presented involve different attached boundary layer flows and are intended to show the performance of the numerical technique. The results obtained are satisfactory and indicative of the possibilities to extend the present meshless technique to more complex flow problems. Copyright (c) 2014 John Wiley & Sons, Ltd.

    In this work, the finite point method is applied to the solution of high-Reynolds compressible viscous flows. The aim is to explore this important field of applications focusing on two main aspects: the easiness and automation of the meshless discretization of viscous layers and the construction of a robust numerical approximation in the highly stretched clouds of points resulting in such domain areas. The flow solution scheme adopts an upwind-biased scheme to solve the averaged Navier-Stokes equations in conjunction with an algebraic turbulence model. The numerical applications presented involve different attached boundary layer flows and are intended to show the performance of the numerical technique. The results obtained are satisfactory and indicative of the possibilities to extend the present meshless technique to more complex flow problems. Copyright (c) 2014 John Wiley & Sons, Ltd.

  • A meshless finite point method for the three-dimensional analysis of compressible flow problems involving moving boundaries and adaptivity

     Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio; Idelsohn Barg, Sergio Rodolfo; Flores Le Roux, Roberto Maurice
    International journal for numerical methods in fluids
    Date of publication: 2013-10-10
    Journal article

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    A finite point method for solving compressible flow problems involving moving boundaries and adaptivity is presented. The numerical methodology is based on an upwind-biased discretization of the Euler equations, written in arbitrary Lagrangian¿Eulerian form and integrated in time by means of a dual-time steeping technique. In order to exploit the meshless potential of the method, a domain deformation approach based on the spring network analogy is implemented, and h-adaptivity is also employed in the computations. Typical movable boundary problems in transonic flow regime are solved to assess the performance of the proposed technique. In addition, an application to a fluid¿structure interaction problem involving static aeroelasticity illustrates the capability of the method to deal with practical engineering analyses. The computational cost and multi-core performance of the proposed technique is also discussed through the examples provided.

  • An adaptive finite point method for the shallow water equations

     Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio; Idelsohn Barg, Sergio Rodolfo; Buachart, Chinapat
    International journal for numerical methods in engineering
    Date of publication: 2011-09-13
    Journal article

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  • PUMI: un código explícito no estructurado para resolver las ecuaciones de Euler

     Flores Le Roux, Roberto Maurice; Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio
    Revista internacional de métodos numéricos para cálculo y diseño en ingeniería
    Date of publication: 2011
    Journal article

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  • Explicit dynamic analysis of thin membrane structures

     Flores Le Roux, Roberto Maurice; Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio
    Date: 2011-02
    Report

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  • An adaptive finite point method for aeroelastic analysis

     Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio; Idelsohn Barg, Sergio Rodolfo
    Date: 2011-10
    Report

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  • Development of a 6-Dof simulator for analysis and evaluation of autonomous parafoil systems

     González, Esteban; Sacco, Carlos; Ortega, Enrique; Flores Le Roux, Roberto Maurice
    Date: 2011-04
    Report

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  • (0718-3291) INGENIARE. Revista Chilena de Ingeniería

     Ortega, Enrique
    Collaboration in journals

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  • Journal of the Franklin Institute

     Ortega, Enrique
    Collaboration in journals

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  • Numerical tools for the analysis of parachutes

     Flores Le Roux, Roberto Maurice; Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio
    International Conference on Textile Composites and Inflatable Structures
    Presentation's date: 2011-10
    Presentation of work at congresses

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  • Numerical Investigation of Wind-Tunnel Model Deformations Caused by the Twin-Sting Support System

     Flores Le Roux, Roberto Maurice; Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio
    Journal of aircraft
    Date of publication: 2010-03
    Journal article

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  • A 3D low-order panel method for unsteady aerodynamic problems

     Ortega, Enrique; Flores Le Roux, Roberto Maurice; Oñate Ibáñez de Navarra, Eugenio
    Date: 2010
    Report

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  • Innovative numerical tools for the simulation of parachutes

     Ortega, Enrique; Flores Le Roux, Roberto Maurice; Oñate Ibáñez de Navarra, Eugenio; Sacco, Carlos; González, Esteban
    Date: 2010
    Report

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  • A finite point method for adaptive three-dimensional compressible flow calculations

     Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio; Idelsohn Barg, Sergio Rodolfo
    International journal for numerical methods in fluids
    Date of publication: 2009-07-30
    Journal article

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  • A finite point method to solve shallow water equations

     Buachart, Chinapat; Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio
    Date: 2009
    Report

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  • A finite point method for compressible flow fluid-structure interaction problems

     Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio; Idelsohn Barg, Sergio Rodolfo
    International Conference on Particle-based Methods
    Presentation's date: 2009-11
    Presentation of work at congresses

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  • (0965-9978) Advances in engineering software

     Ortega, Enrique
    Collaboration in journals

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  • An improved finite point method for tridimensional potential flows

     Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio; Idelsohn Barg, Sergio Rodolfo
    Computational Mechanics
    Date of publication: 2007-11
    Journal article

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  • Stabilized fem-fic formulation for fluid-flow problems with sharp gradients

     Oñate Ibáñez de Navarra, Eugenio; Flores Le Roux, Roberto Maurice; Ortega, Enrique; Idelsohn Barg, Sergio Rodolfo
    Eighth U.S. National Congress on Computational Mechanics
    Presentation's date: 2005
    Presentation of work at congresses

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  • Avances en el método de puntos finitos para problemas de dinámica de fluídos

     Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio; Sacco, C.
    Congreso de Métodos Numéricos en Ingeniería
    Presentation's date: 2005
    Presentation of work at congresses

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  • An edge-based solver for compressible flow

     Ortega, Enrique; Flores Le Roux, Roberto Maurice; Oñate Ibáñez de Navarra, Eugenio
    Date: 2005-10
    Report

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  • Solución de las ecuaciones de flujo compresible mediante el método de puntos finitos

     Ortega, Enrique; Sacco, Carlos G.
    Mecánica computacional
    Date of publication: 2003-11-01
    Journal article

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