1,721,234 research outputs found
Unstructured mesh generation and adaption
No full textAn overview of unstructured mesh generation algorithms and adaption methodologies is given. Some general features are illustrated, trying to stress the key points without detailing the algorithms, whose description may be easily found in the literature
A Stability Analysis for the Arbitrary Lagrangian Eulerian Formulation with Finite Elements
No full textThree-stage multiscale algebraic preconditioner for highly heterogeneous diffusion subsurface problem
No full textPerformances of the Mixed Virtual Element Method on Complex Grids for Underground Flow
No full textThe numerical simulation of physical processes in the underground frequently entails challenges related to the geometry and/or data. The former are mainly due to the shape of sedimentary layers and the presence of fractures and faults, while the latter are connected to the properties of the rock matrix which might vary abruptly in space. The development of approximation schemes has recently focused on the overcoming of such difficulties with the objective of obtaining numerical schemes with good approximation properties. In this work we carry out a numerical study on the performance of the Mixed Virtual Element Method (MVEM) for the solution of a single-phase flow model in fractured porous media. This method is able to handle grid cells of polytopal type and treat hybrid dimensional problems. It has been proven to be robust with respect to the variation of the permeability field and of the shape of the elements. Our numerical experiments focus on two test cases that cover several of the aforementioned critical aspects
Three-stage multiscale algebraic preconditioner for highly heterogeneous diffusion subsurface problem on unstructured mesh
No full textUnified construction of finite element and finite volume discretizations for compressible flows
No full textA framework for the construction of node-centred schemes to solve the compressible Euler and Navier-Stokes equations is presented. The metric quantities are derived by exploiting some properties of CO finite element shape functions. The resulting algorithm allows to implement both artificial diffusion and one-dimensional upwind-type discretizations. The proposed methodology adopts a uniform data structure for diverse grid topologies (structured, unstructured and hybrid) and different element shapes, thus easing code development and maintenance. The final schemes are well suited to run on vector/parallel computer architectures. In the case of linear elements, the equivalence of the proposed method with a particular finite volume formulation is demonstrated
Multiscale algebraic domain decomposition solver with application to uncertainty quantification in highly heterogeneous Darcy flow
No full text
Stability analysis of second order time accurate schemes for ALE-FEM
No full textIn this work we will introduce and analyze the Arbitrary Lagrangian Eulerian formulation for a model problem of a scalar advection-diffusion equation defined on a moving domain. Moving from the results illustrated in our previous work [J. Num. Math. 7 (1999) 105], we will consider first and second-order time advancing schemes and analyze how the movement of the domain might affect accuracy and stability properties of the numerical schemes with respect to their counterpart on fixed domains. Theoretical and numerical results will be presented, showing that stability properties are not, in general, preserved, while accuracy is maintained
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