http://hdl.handle.net/2117/5395 Wed, 19 Jun 2013 06:09:13 GMT 2013-06-19T06:09:13Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/17802 Title: Analysis of an unconditionally convergent stabilized finite element formulation for incompressible magnetohydrodynamics Authors: Badia Rodríguez, Santiago I.; Codina, Ramon; Planas Badenas, Ramon Abstract: In this work, we analyze a recently proposed stabilized finite element formulation for the approximation of the resistive magnetohydrodynamics equations. The novelty of this formulation with respect to existing ones is the fact that it always converges to the physical solution, even when it is singular. We have performed a detailed stability and convergence analysis of the formulation in a simplified setting. From the convergence analysis, we infer that a particular type of meshes with a macro-element structure is needed, which can be easily obtained after a straight modification of any original mesh. Fri, 15 Feb 2013 16:51:15 GMT http://hdl.handle.net/2117/17802 2013-02-15T16:51:15Z Badia Rodríguez, Santiago I.; Codina, Ramon; Planas Badenas, Ramon no magnetohydrodynamics, finite elements, singular solutions, stabilized finite element methods In this work, we analyze a recently proposed stabilized finite element formulation for the approximation of the resistive magnetohydrodynamics equations. The novelty of this formulation with respect to existing ones is the fact that it always converges to the physical solution, even when it is singular. We have performed a detailed stability and convergence analysis of the formulation in a simplified setting. From the convergence analysis, we infer that a particular type of meshes with a macro-element structure is needed, which can be easily obtained after a straight modification of any original mesh. http://hdl.handle.net/2117/16922 Title: Error analysis of discontinuous Galerkin methods for Stokes problem under minimal regularity Authors: Badia Rodríguez, Santiago I.; Codina, Ramon; Gudi, Thirupathi; Guzmán, Johnny Abstract: In this article, we analyze several discontinuous Galerkin methods (DG) for the Stokes problem under the minimal regularity on the solution. We assume that the velocity u belongs to [H1 0 (­)]d and the pressure p 2 L2 0 (­). First, we analyze standard DG methods assuming that the right hand side f belongs to [H¡1(­) \ L1(­)]d. A DG method that is well de¯ned for f belonging to [H¡1(­)]d is then investigated. The methods under study include stabilized DG methods using equal order spaces and inf-sup stable ones where the pressure space is one polynomial degree less than the velocity space. Wed, 14 Nov 2012 18:20:28 GMT http://hdl.handle.net/2117/16922 2012-11-14T18:20:28Z Badia Rodríguez, Santiago I.; Codina, Ramon; Gudi, Thirupathi; Guzmán, Johnny no In this article, we analyze several discontinuous Galerkin methods (DG) for the Stokes problem under the minimal regularity on the solution. We assume that the velocity u belongs to [H1 0 (­)]d and the pressure p 2 L2 0 (­). First, we analyze standard DG methods assuming that the right hand side f belongs to [H¡1(­) \ L1(­)]d. A DG method that is well de¯ned for f belonging to [H¡1(­)]d is then investigated. The methods under study include stabilized DG methods using equal order spaces and inf-sup stable ones where the pressure space is one polynomial degree less than the velocity space. http://hdl.handle.net/2117/16921 Title: On the design of discontinuous Galerkin methods for elliptic problems based on hybrid formulations Authors: Codina, Ramon; Badia Rodríguez, Santiago I. Abstract: The objective of this paper is to present a framework for the design of discontinuous Galerkin (dG) methods for elliptic problems. The idea is to start from a hybrid formulation of the problem involving as unknowns the main field in the interior of the element domains and its fluxes and traces on the element boundaries. Rather than working with this three-field formulation, fluxes are modeled using finite difference expressions and then the traces are determined by imposing continuity of fluxes, although other strategies could be devised. This procedure is applied to four elliptic problems, namely, the convection-diffusion equation (in the diffusion dominated regime), the Stokes problem, the Darcy problem and the Maxwell problem. We justify some well known dG methods with some modifications that in fact allow to improve the performance of the original methods, particularly when the physical properties are discontinuous. Wed, 14 Nov 2012 18:01:39 GMT http://hdl.handle.net/2117/16921 2012-11-14T18:01:39Z Codina, Ramon; Badia Rodríguez, Santiago I. no The objective of this paper is to present a framework for the design of discontinuous Galerkin (dG) methods for elliptic problems. The idea is to start from a hybrid formulation of the problem involving as unknowns the main field in the interior of the element domains and its fluxes and traces on the element boundaries. Rather than working with this three-field formulation, fluxes are modeled using finite difference expressions and then the traces are determined by imposing continuity of fluxes, although other strategies could be devised. This procedure is applied to four elliptic problems, namely, the convection-diffusion equation (in the diffusion dominated regime), the Stokes problem, the Darcy problem and the Maxwell problem. We justify some well known dG methods with some modifications that in fact allow to improve the performance of the original methods, particularly when the physical properties are discontinuous. http://hdl.handle.net/2117/16920 Title: Convergence towards weak solutions of the Navier-Stokes equations for a finite element approximation with numerical subgrid scale modeling Authors: Badia Rodríguez, Santiago I.; Gutiérrez Santacreu, Juan Vicente Abstract: Residual-based stabilized nite element techniques for the Navier-Stokes equations lead to numerical discretizations that provide convection stabilization as well as pressure stability without the need to satisfy an inf-sup condition. They can be motivated by using a variational multiscale framework, based on the decomposition of the uid velocity into a resolvable nite element component plus a modeled subgrid scale component. The subgrid closure acts as a large eddy simulation turbulence model, leading to accurate under-resolved simulations. However, even though variational multiscale formulations are increasingly used in the applied nite element community, their numerical analysis has been restricted to a priori estimates and convergence to smooth solutions only, via a priori error estimates. In this work we prove that some versions of these methods (based on dynamic and orthogonal closures) also converge to weak (turbulent) solutions of the Navier-Stokes equations. These results are obtained by using compactness results in Bochner-Lebesgue spaces. Navier-Stokes equations; stability; convergence; stabilized nite element methods; subgrid scales; variational multiscale methods. Wed, 14 Nov 2012 17:48:02 GMT http://hdl.handle.net/2117/16920 2012-11-14T17:48:02Z Badia Rodríguez, Santiago I.; Gutiérrez Santacreu, Juan Vicente no Residual-based stabilized nite element techniques for the Navier-Stokes equations lead to numerical discretizations that provide convection stabilization as well as pressure stability without the need to satisfy an inf-sup condition. They can be motivated by using a variational multiscale framework, based on the decomposition of the uid velocity into a resolvable nite element component plus a modeled subgrid scale component. The subgrid closure acts as a large eddy simulation turbulence model, leading to accurate under-resolved simulations. However, even though variational multiscale formulations are increasingly used in the applied nite element community, their numerical analysis has been restricted to a priori estimates and convergence to smooth solutions only, via a priori error estimates. In this work we prove that some versions of these methods (based on dynamic and orthogonal closures) also converge to weak (turbulent) solutions of the Navier-Stokes equations. These results are obtained by using compactness results in Bochner-Lebesgue spaces. Navier-Stokes equations; stability; convergence; stabilized nite element methods; subgrid scales; variational multiscale methods. http://hdl.handle.net/2117/16918 Title: Implementation and scalability analysis of balancing domain decomposition methods Authors: Badia Rodríguez, Santiago I.; Martín Huertas, Alberto Francisco; Principe, Ricardo Javier Abstract: Manuscript submitted for publication in SIAM Journal of Scientific Computing. Under Review. Wed, 14 Nov 2012 16:33:11 GMT http://hdl.handle.net/2117/16918 2012-11-14T16:33:11Z Badia Rodríguez, Santiago I.; Martín Huertas, Alberto Francisco; Principe, Ricardo Javier no BDDC, Domain decomposition, parallelization, scalability, coarse-grid correction, balancing domain decomposition, BNN Manuscript submitted for publication in SIAM Journal of Scientific Computing. Under Review. http://hdl.handle.net/2117/16917 Title: Enhanced balancing Neumann-Neumann preconditioning in computational fluid and solid mechanics Authors: Badia Rodríguez, Santiago I.; Martín Huertas, Alberto Francisco; Principe, Ricardo Javier Abstract: Manuscript submitted for publication in International Journal for Numerical Methods in Engineering. Under review. Wed, 14 Nov 2012 16:24:14 GMT http://hdl.handle.net/2117/16917 2012-11-14T16:24:14Z Badia Rodríguez, Santiago I.; Martín Huertas, Alberto Francisco; Principe, Ricardo Javier no parallelization, scalability, Domain decomposition, coarse-grid correction, balancing domain decomposition, BNN, BDDC, elasticity Manuscript submitted for publication in International Journal for Numerical Methods in Engineering. Under review. http://hdl.handle.net/2117/15755 Title: On an unconditionally convergent stabilized finite element approximation of resistive magnetohydrodynamics Authors: Badia Rodríguez, Santiago I.; Codina, Ramon; Planas Badenas, Ramon Abstract: In this work, we propose a new stabilized finite element formulation for the approximation of the resistive magnetohydrodynamics equations. The novelty of this formulation with respect to existing ones is the fact that it always converges to the physical solution, even for singular ones. We have performed a detailed stability and convergence analysis of the formulation in a simplified setting. From the convergence analysis, we infer that a particular type of meshes with a macro-element structure is needed, which can be easily obtained after a straight modification of any original mesh. A detailed set of numerical experiments have been performed in order to validate our approach. Wed, 25 Apr 2012 08:43:13 GMT http://hdl.handle.net/2117/15755 2012-04-25T08:43:13Z Badia Rodríguez, Santiago I.; Codina, Ramon; Planas Badenas, Ramon no In this work, we propose a new stabilized finite element formulation for the approximation of the resistive magnetohydrodynamics equations. The novelty of this formulation with respect to existing ones is the fact that it always converges to the physical solution, even for singular ones. We have performed a detailed stability and convergence analysis of the formulation in a simplified setting. From the convergence analysis, we infer that a particular type of meshes with a macro-element structure is needed, which can be easily obtained after a straight modification of any original mesh. A detailed set of numerical experiments have been performed in order to validate our approach. http://hdl.handle.net/2117/14162 Title: Manual de buenas prácticas para fomentar el aprendizaje en las asignaturas de resistencia de materiales y estructuras Authors: Suárez Arroyo, Benjamín; Rivera Amores, Juan José; Ferrer Ballester, Miquel Abstract: El Manual está estructurado en tres grandes capítulos y unas consideraciones finales. Cada uno de estos capítulos trata aspectos diferentes pero complementarios. El primero nos introduce en el EEES, haciendo referencia a los diferentes modelos educativos y su incidencia en el entorno social. El segundo capítulo nos permite conocer propuestas formativas desarrolladas por diferentes profesores del Departamento de RMEE. El tercer capítulo enmarca todo lo que se ha comentado en los otros dos, mediante unas reflexiones estructuradas en cinco áreas que permiten entender cuál es el verdadero sentido de la propuesta EEES, cuál será el alcance de éste trabajo y como la afrontarán tanto los profesores como los estudiantes. Finalmente y como colofón encontramos unas consideraciones que hacen referencia a como la sociedad del siglo XXI afrontará estos cambios, tanto a nivel conceptual como estratégico. Fri, 02 Dec 2011 14:46:01 GMT http://hdl.handle.net/2117/14162 2011-12-02T14:46:01Z Suárez Arroyo, Benjamín; Rivera Amores, Juan José; Ferrer Ballester, Miquel no El Manual está estructurado en tres grandes capítulos y unas consideraciones finales. Cada uno de estos capítulos trata aspectos diferentes pero complementarios. El primero nos introduce en el EEES, haciendo referencia a los diferentes modelos educativos y su incidencia en el entorno social. El segundo capítulo nos permite conocer propuestas formativas desarrolladas por diferentes profesores del Departamento de RMEE. El tercer capítulo enmarca todo lo que se ha comentado en los otros dos, mediante unas reflexiones estructuradas en cinco áreas que permiten entender cuál es el verdadero sentido de la propuesta EEES, cuál será el alcance de éste trabajo y como la afrontarán tanto los profesores como los estudiantes. Finalmente y como colofón encontramos unas consideraciones que hacen referencia a como la sociedad del siglo XXI afrontará estos cambios, tanto a nivel conceptual como estratégico. http://hdl.handle.net/2117/6814 Title: Análisis numérico del proceso de filtración en presas de escollera Authors: Tapia Navarro, Cristian; Oñate Ibáñez de Navarra, Eugenio; Larese De Tetto, Antonia Abstract: Las presas de materiales sueltos funcionan como presas de gravedad, el peso propio de los materiales que la componen aportan la resistencia necesaria para soportar el empuje horizontal y la flexión que producen las aguas en el trasdós. El inconveniente principal de éstas presas está en el sobrevertido. Si se produce una avenida y el agua vierte sobre la presa, ésta se comporta de manera inestable y puede colapsarse y desmoronarse. Se sabe que este fenómeno del sobrevertido es una de las principales razones por las que colapsan este tipo de presas, pero se trata de un fenómeno poco conocido y poco desarrollado. Por ello existe un interés cada vez mayor en el estudio del comportamiento de las presas de materiales sueltos cuando se lleva a cabo el llenado, y el sobrevertido de agua sobre el talud aguas abajo. Este estudio está limitado por la ausencia de un método de cálculo, por lo que es esencial llegar a constituir un método numérico que modelice el comportamiento físico de estos procesos en dichas presas. Fri, 26 Mar 2010 17:59:59 GMT http://hdl.handle.net/2117/6814 2010-03-26T17:59:59Z Tapia Navarro, Cristian; Oñate Ibáñez de Navarra, Eugenio; Larese De Tetto, Antonia no UPM, CIMNE, KRATOS, CEDEX, presas de materiales sueltos, sobrevertido, filtración, método numérico, elementos finitos, datos experimentales Las presas de materiales sueltos funcionan como presas de gravedad, el peso propio de los materiales que la componen aportan la resistencia necesaria para soportar el empuje horizontal y la flexión que producen las aguas en el trasdós. El inconveniente principal de éstas presas está en el sobrevertido. Si se produce una avenida y el agua vierte sobre la presa, ésta se comporta de manera inestable y puede colapsarse y desmoronarse. Se sabe que este fenómeno del sobrevertido es una de las principales razones por las que colapsan este tipo de presas, pero se trata de un fenómeno poco conocido y poco desarrollado. Por ello existe un interés cada vez mayor en el estudio del comportamiento de las presas de materiales sueltos cuando se lleva a cabo el llenado, y el sobrevertido de agua sobre el talud aguas abajo. Este estudio está limitado por la ausencia de un método de cálculo, por lo que es esencial llegar a constituir un método numérico que modelice el comportamiento físico de estos procesos en dichas presas. http://hdl.handle.net/2117/6812 Title: CIMNE Verification of the validation analisis of Xfinas elements database Authors: Larese De Tetto, Antonia; Oñate Ibáñez de Navarra, Eugenio Abstract: In order to validate the Xfinas code a very comprehensive series of test examples were solved by Prof Ki-Du Kim and his co-workers. A collection of the more representative benchmarks were chosen at CIMNE for testing the good behavior of every element implemented in the software. The aim of the validation work carried out at CIMNE has been to asses the accuracy of the Xfinas program. This was done studying the whole validation process carried out by Prof Ki-Du Kim’s team in detail. For this purpose we have chosen at CIMNE randomly the different benchmarks to be reproduced between those of the validation manual (VM from now on). In every example we checked the agreement of the results with the Xfinas validation data. Fri, 26 Mar 2010 17:52:21 GMT http://hdl.handle.net/2117/6812 2010-03-26T17:52:21Z Larese De Tetto, Antonia; Oñate Ibáñez de Navarra, Eugenio no In order to validate the Xfinas code a very comprehensive series of test examples were solved by Prof Ki-Du Kim and his co-workers. A collection of the more representative benchmarks were chosen at CIMNE for testing the good behavior of every element implemented in the software. The aim of the validation work carried out at CIMNE has been to asses the accuracy of the Xfinas program. This was done studying the whole validation process carried out by Prof Ki-Du Kim’s team in detail. For this purpose we have chosen at CIMNE randomly the different benchmarks to be reproduced between those of the validation manual (VM from now on). In every example we checked the agreement of the results with the Xfinas validation data. http://hdl.handle.net/2117/6809 Title: Trabajo realizado por CIMNE en relacción con la rotura del muelle del Prat del puerto de Barcelona Authors: Oñate Ibáñez de Navarra, Eugenio; Suárez Arroyo, Benjamín; Idelsohn Barg, Sergio Rodolfo; Rossi, Riccardo; Celigueta Jordana, Miguel Ángel; Larese De Tetto, Antonia Abstract: La Autoridad Portuaria de Barcelona (APB) está interesada en conocer las causas que originaron la avería del Muelle de Prat el día 1 de Enero de 2007. El Centro Internacional de Métodos Numéricos en Ingeniería (CIMNE), consorcio entre la Generalitat de Cataluña y la Universidad Politécnica de Cataluña, ha desarrollado durante los últimos años formulaciones matemáticas y herramientas de cálculo específicas para resolver este tipo de problemas. APB y CIMNE tienen una gran experiencia en trabajar juntos en estudios y análisis de carácter científico técnico. Fri, 26 Mar 2010 15:57:40 GMT http://hdl.handle.net/2117/6809 2010-03-26T15:57:40Z Oñate Ibáñez de Navarra, Eugenio; Suárez Arroyo, Benjamín; Idelsohn Barg, Sergio Rodolfo; Rossi, Riccardo; Celigueta Jordana, Miguel Ángel; Larese De Tetto, Antonia no La Autoridad Portuaria de Barcelona (APB) está interesada en conocer las causas que originaron la avería del Muelle de Prat el día 1 de Enero de 2007. El Centro Internacional de Métodos Numéricos en Ingeniería (CIMNE), consorcio entre la Generalitat de Cataluña y la Universidad Politécnica de Cataluña, ha desarrollado durante los últimos años formulaciones matemáticas y herramientas de cálculo específicas para resolver este tipo de problemas. APB y CIMNE tienen una gran experiencia en trabajar juntos en estudios y análisis de carácter científico técnico.