5,513 research outputs found
Contro la funzionalizzazione della contrattazione collettiva. Riflessioni sul pensiero di Mario Rusciano
No full textL'autore riflette sul pensiero di Mario Rusciano in punto di funzionalizzazione della contrattazione collettiva.The author reflects on the thought of Mario Rusciano in relation to the subject of the functionalisation of collective bargaining
An explicit residual based approach for shallow water flows
No full textWe describe a fully explicit residual based construction to discretize the shallow water equations with friction on unstructured grids. The approach is by construction exactly well balanced for al the simple known steady equilibria, and it shows a super-covergent behavior for smooth non-trivial equilibria, as the implicit residual schemes considered in (Ricchiuto, J.Sci.Comp. 48,2011). Moreover, by adapting the wetting drying technique discussed in (Ricchiuto and Bolermann, JCP 228, 2009) the scheme is able to preserve the non-negativity of the depth and to handle very well the runup and flooding of complex bathymetries. The approach is analyzed and tested thoroughly. The numerical results on a large variety of problems show the interest in the approach.On considere un schema explicite et residual based pour la discretisation des equations shallow water sur maillages non-structures. L'approche est par construction exactement well balanced pour tous les équilibres plus simples connus en littérature, mais il montre une super-convergence pour certains équilibres non-triviaux, comme les schemas implicites consideres en (Ricchiuto, J.Sci.Comp. 48,2011). En adaptant la strategie de wetting/drying présentée en (Ricchiuto and Bolermann, JCP 228, 2009) le schema permet en plus de garantir la non-négativite de la profondeur et de simuler runup et inondation de bathymetries complexes. La methode est analysée et testée sur un nombre important de problèmes. Les résultats montrent l'intérêt de l'approch
An explicit residual based approach for shallow water flows
No full textWe describe a fully explicit residual based construction to discretize the shallow water equations with friction on unstructured grids. The approach is by construction exactly well balanced for al the simple known steady equilibria, and it shows a super-covergent behavior for smooth non-trivial equilibria, as the implicit residual schemes considered in (Ricchiuto, J.Sci.Comp. 48,2011). Moreover, by adapting the wetting drying technique discussed in (Ricchiuto and Bolermann, JCP 228, 2009) the scheme is able to preserve the non-negativity of the depth and to handle very well the runup and flooding of complex bathymetries. The approach is analyzed and tested thoroughly. The numerical results on a large variety of problems show the interest in the approach.On considere un schema explicite et residual based pour la discretisation des equations shallow water sur maillages non-structures. L'approche est par construction exactement well balanced pour tous les équilibres plus simples connus en littérature, mais il montre une super-convergence pour certains équilibres non-triviaux, comme les schemas implicites consideres en (Ricchiuto, J.Sci.Comp. 48,2011). En adaptant la strategie de wetting/drying présentée en (Ricchiuto and Bolermann, JCP 228, 2009) le schema permet en plus de garantir la non-négativite de la profondeur et de simuler runup et inondation de bathymetries complexes. La methode est analysée et testée sur un nombre important de problèmes. Les résultats montrent l'intérêt de l'approch
An explicit residual based approach for shallow water flows
Full text linkWe describe a fully explicit residual based construction to discretize the shallow water equations with friction on unstructured grids. The approach is by construction exactly well balanced for al the simple known steady equilibria, and it shows a super-covergent behavior for smooth non-trivial equilibria, as the implicit residual schemes considered in (Ricchiuto, J.Sci.Comp. 48,2011). Moreover, by adapting the wetting drying technique discussed in (Ricchiuto and Bolermann, JCP 228, 2009) the scheme is able to preserve the non-negativity of the depth and to handle very well the runup and flooding of complex bathymetries. The approach is analyzed and tested thoroughly. The numerical results on a large variety of problems show the interest in the approach.On considere un schema explicite et residual based pour la discretisation des equations shallow water sur maillages non-structures. L'approche est par construction exactement well balanced pour tous les équilibres plus simples connus en littérature, mais il montre une super-convergence pour certains équilibres non-triviaux, comme les schemas implicites consideres en (Ricchiuto, J.Sci.Comp. 48,2011). En adaptant la strategie de wetting/drying présentée en (Ricchiuto and Bolermann, JCP 228, 2009) le schema permet en plus de garantir la non-négativite de la profondeur et de simuler runup et inondation de bathymetries complexes. La methode est analysée et testée sur un nombre important de problèmes. Les résultats montrent l'intérêt de l'approch
An explicit residual based approach for shallow water flows
No full textWe describe a fully explicit residual based construction to discretize the shallow water equations with friction on unstructured grids. The approach is by construction exactly well balanced for al the simple known steady equilibria, and it shows a super-covergent behavior for smooth non-trivial equilibria, as the implicit residual schemes considered in (Ricchiuto, J.Sci.Comp. 48,2011). Moreover, by adapting the wetting drying technique discussed in (Ricchiuto and Bolermann, JCP 228, 2009) the scheme is able to preserve the non-negativity of the depth and to handle very well the runup and flooding of complex bathymetries. The approach is analyzed and tested thoroughly. The numerical results on a large variety of problems show the interest in the approach.On considere un schema explicite et residual based pour la discretisation des equations shallow water sur maillages non-structures. L'approche est par construction exactement well balanced pour tous les équilibres plus simples connus en littérature, mais il montre une super-convergence pour certains équilibres non-triviaux, comme les schemas implicites consideres en (Ricchiuto, J.Sci.Comp. 48,2011). En adaptant la strategie de wetting/drying présentée en (Ricchiuto and Bolermann, JCP 228, 2009) le schema permet en plus de garantir la non-négativite de la profondeur et de simuler runup et inondation de bathymetries complexes. La methode est analysée et testée sur un nombre important de problèmes. Les résultats montrent l'intérêt de l'approch
An explicit residual based approach for shallow water flows
Full text linkInternational audienceWe describe fully explicit residual based discretizations of the shallow water equations with friction on unstructured grids. The schemes are obtained by properly adapting the explicit construction proposed in Ricchiuto and Abgrall (2010) . In particular, previous work on well balanced integration (Ricchiuto, 2011 ) and preservation of the depth non-negativity (Ricchiuto and Bollermann, 2009 ) is reformulated in the context of a genuinely explicit time stepping still based on a weighted residual approximation. The paper discusses in depth how to achieve in this context an exact preservation of all the simple known steady equilibria, and how to obtain a super-consistent approximation for smooth non-trivial moving equilibria. The treatment of the wetting/drying interface is also discussed, giving formal conditions for the preservation of the non-negativity of the depth for a particular case, based on a nonlinear variant of a Lax–Friedrichs type scheme. The approach is analyzed and tested thoroughly. The quality of the numerical results shows the interest in the proposed approach over previously proposed schemes, in terms of accuracy and efficiency
An ALE formulation for explicit Runge-Kutta Residual Distribution
No full textIn this paper we consider the solution of hyperbolic conservation laws on moving meshes by means of an Arbitrary Lagrangian Eulerian (ALE) formulation. In particular we propose an ALE framework for the genuinely explicit residual distribution schemes of (Ricchiuto and Abgrall {\it J.Comput.Phys} 229, 2010). The discretizations obtained are thoroughly tested on a large number of benchmarks.Dans ce travail on considére la resolution de lois de conservation sur maillages mobiles par une formulation Arbitrary Lagrangian Eulerian (ALE). On propose en particulier un formalisme ALE pour les schémas RD explicites de (Ricchiuto and Abgrall {\it J.Comput.Phys} 229, 2010). Les schémas ainsi obtenus sont testés sur des nombreux benchmarks
An ALE formulation for explicit Runge-Kutta Residual Distribution
No full textIn this paper we consider the solution of hyperbolic conservation laws on moving meshes by means of an Arbitrary Lagrangian Eulerian (ALE) formulation. In particular we propose an ALE framework for the genuinely explicit residual distribution schemes of (Ricchiuto and Abgrall {\it J.Comput.Phys} 229, 2010). The discretizations obtained are thoroughly tested on a large number of benchmarks.Dans ce travail on considére la resolution de lois de conservation sur maillages mobiles par une formulation Arbitrary Lagrangian Eulerian (ALE). On propose en particulier un formalisme ALE pour les schémas RD explicites de (Ricchiuto and Abgrall {\it J.Comput.Phys} 229, 2010). Les schémas ainsi obtenus sont testés sur des nombreux benchmarks
High order methods for CFD
Full text linkInternational audienceWe provide a review of high order methods for CFD. Besides recalling some classical methods, we show a framework allowing on one hand to see and work with these methods under a different light, and on the other to provide a different path to construct numerical methods for flow equations. In particular, we focus on Residual Based techniques, and Residual Distribution methods, as a framework to construct schemes of arbitrary order. The somewhat classical second-order multidimensional upwind fluctuation-splitting/residual-distribution schemes are reviewed in the chapter by Deconinck and Ricchiuto
High order methods for CFD
No full textInternational audienceWe provide a review of high order methods for CFD. Besides recalling some classical methods, we show a framework allowing on one hand to see and work with these methods under a different light, and on the other to provide a different path to construct numerical methods for flow equations. In particular, we focus on Residual Based techniques, and Residual Distribution methods, as a framework to construct schemes of arbitrary order. The somewhat classical second-order multidimensional upwind fluctuation-splitting/residual-distribution schemes are reviewed in the chapter by Deconinck and Ricchiuto
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