Now showing items 41-60 of 245

• #### On continuous and discrete maximum principles for elliptic problems with the third boundary condition ﻿

(2013-12-31)
In this work, we present and discuss some continuous and discrete maximum principles for linear elliptic problems of the second order with the third boundary condition (almost never addressed to in the available literature ...
• #### An IMEX scheme combined with Richardson extrapolation methods for some reaction-diffusion equations ﻿

(2013-12-31)
An implicit-explicit (IMEX) method is combined with some so-called Richardson extrapolation (RiEx) methods for the numerical solution of reaction-diffusion equations with pure Neumann boundary conditions. The results are ...
• #### A two-level finite element discretization of the streamfunction formulation of the stationary quasi-geostrophic equations of the ocean ﻿

(2013-12-31)
In this paper we proposed a two-level finite element discretization of the nonlinear stationary quasi-geostrophic equations, which model the wind driven large scale ocean circulation. Optimal error estimates for the two-level ...
• #### Towards the development of adaptive finite element methods for internal flow aeroacoustics ﻿

(2013-12-31)
We report the latest results obtained in the development of an adaptive finite element method for computational aeroacoustics (CAA). The new methodology is based on the General Galerkin (G2) method, which has been successfully ...
• #### Computation of slat noise sources using adaptive FEM and lighthill's analogy ﻿

(2013-12-31)
This is a summary of preliminary results from simulations with the 30P30N high-lift device. We used the General Galerkin finite element method (G2), where no explicit subgrid model is used, and where the computational mesh ...
• #### A variational finite element model for large-eddy simulations of turbulent flows ﻿

(2013-12-31)
The authors introduce a new Large Eddy Simulation model in a channel, based on the projection on finite element spaces as filtering operation in its variational form, for a given triangulation {T h}h&gt;0. The eddy viscosity ...
• #### Framework for adaptive fluid-structure interaction with industrial applications ﻿

(2013-12-31)
We present developments in the Unicorn-HPC framework for unified continuum mechanics, enabling adaptive finite element computation of fluid-structure interaction, and an overview of the larger FEniCS-HPC framework for ...
• #### High-order mixed weighted compact and non-compact scheme for shock and small length scale interaction ﻿

(2013-12-31)
It is critical for a numerical scheme to obtain numerical results as accurate as possible with limited computational resources. Turbulent processes are very sensitive to numerical dissipation, which may dissipate the small ...
• #### A Bochev-Dohrmann-Gunzburger stabilization method for the primitive equations of the ocean ﻿

(2013-12-31)
We introduce a low-order stabilized discretization of the primitive equations of the ocean with highly reduced computational complexity. We prove stability through a specific inf-sup condition, and weak convergence to a ...
• #### 3D hp-Adaptive Finite Element Simulations of Bend, Step, and Magic-T Electromagnetic Waveguide Structures ﻿

(2014-03)
Metallic rectangular waveguides are often the preferred choice on telecommunication systems and medical equipment working on the upper microwave and millimeter wave frequency bands due to the simplicity of its geometry, ...
• #### Fast 1D Inversion of Logging-While-Drilling Resistivity Measurements for Improved Estimation of Formation Resistivity in High-Angle and Horizontal Wells ﻿

(2014-12)
We have developed an efficient inversion method to estimate layer-by-layer electric resistivity from loggingwhile-drilling electromagnetic induction measurements. The method assumes a 1D model based on planarly layered ...
• #### A hybrid method for inversion of 3D DC resistivity logging measurements ﻿

(2014-12-31)
This paper focuses on the application of hp hierarchic genetic strategy (hp-HGS) for solution of a challenging problem, the inversion of 3D direct current (DC) resistivity logging measurements. The problem under consideration ...
• #### Fast simulation of through-casing resistivity measurements using semi-analytical asymptotic models. Part 1: Accuracy study ﻿

(2014-12-31)
When trying to obtain a better characterization of the Earth's subsurface, it is common to use borehole through-casing resistivity measurements. It is also common for the wells to be surrounded by a metal casing to protect ...
• #### Low cost a posteriori error estimators for an augmented mixed FEM in linear elasticity. Dedicated to Professor Rodolfo Rodríguez on the occasion of his 60th birthday. ﻿

(2014-12-31)
We consider an augmented mixed finite element method applied to the linear elasticity problem and derive a posteriori error estimators that are simpler and easier to implement than the ones available in the literature. In ...
• #### Analysis of extreme wave events on the southern coast of Brazil ﻿

(2014-12-31)
Using the wave model SWAN (simulating waves nearshore), high waves on the southwestern Atlantic generated by extra-tropical cyclones are simulated from 2000 to 2010, and their impact on the Rio Grande do Sul (RS) coast is ...
• #### Computational cost estimates for parallel shared memory isogeometric multi-frontal solvers ﻿

(2014-12-31)
• #### Red refinements of simplices into congruent subsimplices ﻿

(2014-12-31)
We show that in dimensions higher than two, the popular "red refinement" technique, commonly used for simplicial mesh refinements and adaptivity in the finite element analysis and practice, never yields subsimplices which ...
• #### Hypersingular integral equations over a disc: Convergence of a spectral method and connection with Tranter's method ﻿

(2014-12-31)
Two-dimensional hypersingular equations over a disc are considered. A spectral method is developed, using Fourier series in the azimuthal direction and orthogonal polynomials in the radial direction. The method is proved ...