Listar por autor "Navarrina, Fermín"
Mostrando ítems 21-40 de 98
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A numerical formulation for grounding analysis in stratified soils
Colominas, Ignasi; Navarrina, Fermín; Casteleiro, Manuel (IEEE Power Engineering Society, 2002)[Abstract] The design of safe grounding systems in electrical installations is essential to assure the security of the persons, the protection of the equipment and the continuity of the power supply. In order to achieve ... -
A particle numerical approach based on the SPH method for computational fluid Mechanics
Colominas, Ignasi; Cueto-Felgueroso Landeira, Luis; Mosqueira Martínez, Gonzalo; Navarrina, Fermín; Casteleiro, Manuel (2004)[Abstract] Meshfree methods have experimented an important improvement in the last decade. Actually, we can say that the emerging meshless technology constitutes the most promising tool to simulate complex problems in ... -
A stabilized finite element approach for advective-diffusive transport problems
Figueroa Álvarez, Carlos Alberto; Colominas, Ignasi; Mosqueira Martínez, Gonzalo; Navarrina, Fermín; Casteleiro, Manuel (Escola Politécnica da Universidade de Sao Paulo, 1999)[Abstract] As it is well-know, the numerical simulation in fluid mechanics is quite difficult specially when the velocity of the fluid is important. These problems are reflected in the apparearance of numerical oscillations ... -
A unified approach for high order sensitivity analysis
Navarrina, Fermín; Colominas, Ignasi; Juanes, Rubén; Bendito Pérez, Enrique; Casteleiro, Manuel (Computational Mechanics Publications, 2001)[Abstract] Many engineering problems require solving PDEs by means of numerical methods (type FEM/BEM) which sensivity analysis entails taking derivatives of functions defined through integration. In sizing optimization ... -
A validation of the boundary element method for grounding grid design and computation
Colominas, Ignasi; Navarrina, Fermín; Casteleiro, Manuel (Centro Internacional de Métodos Numéricos en Ingeniería, CIMNE (Barcelona), 1992)[Abstract] Several widespread intuitive techniques developed during the last two decades for substation grounding analysis, such as the Average Potential Method (APM), have been recently identified as particular cases of ... -
An efficient MP algorithm for structural shape optimization problems
Navarrina, Fermín; Tarrech i Masdeu, Ramón; Colominas, Ignasi; Mosqueira Martínez, Gonzalo; Gómez Calviño, Javier; Casteleiro, Manuel (Computational Mechanics Publications, 2001)[Abstract] Integral methods -such as the Finite Element Method (FEM) and the Boundary Element Method (BEM)- are frequently used in structural optimization problems to solve systems of partial differential equations. ... -
An enriched meshless numerical approach for potential theory problems
Mosqueira Martínez, Gonzalo; Colominas, Ignasi; Navarrina, Fermín; Casteleiro, Manuel (The International Center of Numerical Methods in Engineering, 2000)[Abstract] One of the meshless thechniques that have been recently proposed for solving Boundary Value Problems is the so-called Weighted Least Square (WLS) Method with a Point Collocation approach. Meshless methods were ... -
Analysis of transferred earth potentials in grounding systems: a BEM numerical approach
Colominas, Ignasi; Navarrina, Fermín; Casteleiro, Manuel (IEEE Power Engineering Society, 2003)[Abstract] In this work we present a numerical formulation for the analysis of a common problem in electrical engineering practice, that is, the existence of transferred earth potentials in a grounding installation [1]. ... -
Analytical integration techniques for earthing grid computation by boundary element methods
Navarrina, Fermín; Colominas, Ignasi; Casteleiro, Manuel (Centro Internacional de Métodos Numéricos en Ingeniería, CIMNE (Barcelona), 1992)[Abstract] Analysis and design of substation earthing involves computing the equivalent resistance of grounding systems, but also distribution of potentials on the earth surface due to fault currents [1]. While very crude ... -
Análisis de formulaciones numéricas SPH para la resolución de problemas de flujo con superficie libre
Cueto-Felgueroso Landeira, Luis; Mosqueira Martínez, Gonzalo; Colominas, Ignasi; Navarrina, Fermín; Casteleiro, Manuel (2002)[Abstract] El objetivo de este artículo es estudiar las distintas formulaciones tipo Smooth Particle Hydrodynamics (SPH) propuestas para aplicaciones a problemas de fluidos, especialmente los relacionados con flujo en ... -
Aplicación de una formulación numérica de elementos finitos para el estudio de problemas de transporte convectivo en zonas portuarias
Figueroa Álvarez, Carlos Alberto; Colominas, Ignasi; Iglesias Rodríguez, Gregorio; Navarrina, Fermín; Casteleiro, Manuel (Sociedad Española de Métodos Numéricos en Ingeniería, 1999)[Resumen] La ecuación diferencial del trasporte por convección-difusión permite modelizar un gran número de procesos de interés en la ingeniería. Así, fenómenos com el estudio de la distribución de temperaturas en una pieza ... -
Application of meshless methods to the analysis and design of grounding systems
Colominas, Ignasi; Chao López, Mar; Navarrina, Fermín; Casteleiro, Manuel (Centro Internacional de Métodos Numéricos en Ingeniería, 1998)[Abstract] Analysis and design of grounding systems of electrical installations involves computing the potential distribution in the earth and the equivalent resistance of the system. Several numerical formulations based ... -
Boundary element formulation for the analysis of transferred potentials in electrical installations
Colominas, Ignasi; Navarrina, Fermín; Casteleiro, Manuel (Elsevier, 2004)[Abstract] In this work we present a BEM numerical formulation for the analysis of a common problem in electrical engineering practice, that is, the existence of transferred earth potentials in a grounding installation ... -
Cálculo de potenciales transferidos en grandes sistemas de redes de tierra de subestaciones eléctricas
Colominas, Ignasi; Navarrina, Fermín; Gómez Calviño, Javier; Casteleiro, Manuel (Departamento de Matemática Aplicada, Universidad de Salamanca, 2001)[Resumen] En este artículo se presenta el análisis mediante una formulación numérica de elementos de contorno de un problema común en la ingeniería eléctrica como es la existencia de potenciales transferidos en una instalación ... -
Cálculo y diseño asistido por ordenador de tomas de tierra para subestaciones eléctricas
Colominas, Ignasi; Navarrina, Fermín; Casteleiro, Manuel (2002)[Resumen] En este trabajo se presenta una formulaci´on num´erica para el c´alculo y dise˜no asistido por ordenador de tomas de tierra que es aplicable a un amplio rango de instalaciones el´ectricas reales. La formulaci´on ... -
Computer analysis of earthing systems in horizontally or vertically layered soils
Colominas, Ignasi; Gómez Calviño, Javier; Navarrina, Fermín; Casteleiro, Manuel (Elsevier, 2001)[Abstract] The main objectives of grounding systems are to guarantee the personal safety, the equipment protection and the continuity of the power supply. To attain these goals, the potential distribution on the earth ... -
Computer software for analysis and design optimization of power transmission structures by simulated annealing and sensitivity analysis
Couceiro, Iván; París, José; Navarrina, Fermín; Colominas, Ignasi; Martínez Varela, Santiago (Springer, 2021)[Abstract:] This paper presents a computer software for the optimization of power transmission structures. The software employs a modified version of the Simulated Annealing algorithm that has been proven effective in large ... -
Computing stabilization parameters in numerical models for advective-diffusive transport problems
Colominas, Ignasi; López Jato, Raquel; Figueroa Álvarez, Carlos Alberto; Navarrina, Fermín; Casteleiro, Manuel (Universidade de Aveiro, 2000)[Abstract] Numerical modelling in Fluid Mechanics is particulary difficult in high-advective fluid problems. The Finite Element Method, which has been sucessfully applied to very challenging problems in Computational ... -
Desarrollo de una formulación basada en los métodos multiescala para la resolución de problemas de transporte convectivo-difusivos
López Jato, Raquel; Colominas, Ignasi; Navarrina, Fermín; Casteleiro, Manuel (2002)[Resumen] La resolución de la ecuación de convección-difusión mediante el Método de los Elementos Finitos con ponderación convencional tipo Galerkin presenta numerosas inestabilidades cuando la velocidad del fluido es ... -
Desarrollo de una formulación numérica basada en el MEF para la estabilización de problemas de transporte por convección-difusión
Figueroa Álvarez, Carlos Alberto; Colominas, Ignasi; Mosqueira Martínez, Gonzalo; Navarrina, Fermín; Casteleiro, Manuel (Sociedad Española de Métodos Numéricos en Ingeniería, 1999)[Resumen] La modelización de problemas en mecánica de fluidos cuando la velocidad del fluido es elevada resulta complicada debido a la aparición de inestabilidades en la solución numérica al emplear esquemas convencionales ...