Now showing items 144-163 of 171

• #### Semi-analytical response of acoustic logging measurements in frequency domain ﻿

(Computers and Mathematics with Applications, 2015-12-31)
This work proposes a semi-analytical method for simulation of the acoustic response of multipole eccentered sources in a fluid-filled borehole. Assuming a geometry that is invariant with respect to the azimuthal and vertical ...
• #### Sensitivity study of borehole-to-surface and crosswell electromagnetic measurements acquired with energized steel casing to water displacement in hydrocarbon-bearing layers ﻿

(Geophysics, 2008-12-31)
We study the theoretical response of electromagnetically energized steel casing in the presence of subsurface variations of electrical resistivity. Casing is energized with a finite-size solenoid antenna located along the ...
• #### SimTek - an edX-based platform for Mathematical Multi-physics Simulation ﻿

(International Conference on MOOCs in Scandinavia, 2015-12-31)
[No abstract available]
• #### Simulation of DC dual-laterolog measurements in complex formations: A Fourier-series approach with nonorthogonal coordinates and self-adapting finite elements ﻿

(Geophysics, 2009-12-31)
Dual laterolog (DLL) makes use of a galvanic conduction principle to focus electrical currents into rock formations, thereby minimizing shoulder and borehole effects in the measurement of formation resistivity. The tool ...
• #### Simulation of marine controlled source electromagnetic measurements using a parallel fourier hp-finite element method ﻿

(Computational Geosciences, 2011-12-31)
We introduce a new numerical method to simulate geophysical marine controlled source electromagnetic (CSEM) measurements for the case of 2D structures and finite 3D sources of electromagnetic (EM) excitation. The method ...
• #### Simulation of the HarshLab floating platform for offshore experimentation using FEniCS-HPC ﻿

(Poster EUSKAMPUS IV Marine Energy Conference, 2017)
• #### Singular dynamics under a weak potential on a sphere ﻿

(Nonlinear Differential Equations and Applications, 2013-12-31)
We give a detailed analytical description of the global dynamics of a point mass moving on a sphere under the action of a logarithmic potential. We perform a McGehee-type blow-up in order to cope with the singularity of ...
• #### Some discrete maximum principles arising for nonlinear elliptic finite element problems ﻿

(Computers and Mathematics with Applications, 2015-12-31)
The discrete maximum principle (DMP) is an important measure of the qualitative reliability of the applied numerical scheme for elliptic problems. This paper starts with formulating simple sufficient conditions for the ...
• #### Source time reversal (STR) method for linear elasticity ﻿

(Computers & Mathematics with Applications, 2018)
We study the problem of source reconstruction for a linear elasticity problem applied to seismicity induced by mining. We assume the source is written as a variable separable function $\mathbf{f(x)}\>g(t)$ . We first present ...
• #### A source time reversal method for seismicity induced by mining ﻿

(Inverse Problems and Imaging, 2017-01-01)
In this work, we present a modified Time-Reversal Mirror (TRM) Method, called Source Time Reversal (STR), to find the spatial distribution of a seismic source induced by mining activity. This methodology is based on a known ...
• #### A space-time DPG method for the wave equation in multiple dimensions ﻿

(RICAM book series, 2019)
A space-time discontinuous Petrov–Galerkin (DPG) method for the linear wave equation is presented. This method is based on a weak formulation that uses a broken graph space. The well-posedness of this formulation is ...
• #### Spray Drag Effect of Fluidized Sand for a Supersonic Vehicle ﻿

(Journal of Coupled Systems and Multiscale Dynamics, 2014-12-31)
This paper deals with fluidized sand simulation in order to estimate the impact of sand particle motion on the BLOODHOUND SuperSonic Car (SSC) drag forces, such phenomenon is known as a spray drag effect. A gas-particle ...
• #### Stabilized dual-mixed method for the problem of linear elasticity with mixed boundary conditions ﻿

(Applied Mathematics Letters, 2014-12-31)
We extend the applicability of the augmented dual-mixed method introduced recently in Gatica (2007), Gatica et al. (2009) to the problem of linear elasticity with mixed boundary conditions. The method is based on the ...
• #### Super Abrasive Machining of Integral Rotary Components Using Grinding Flank Tools ﻿

(Metals, 2018-01-01)
Manufacturing techniques that are applied to turbomachinery components represent a challenge in the aeronautic sector. These components require high resistant super-alloys in order to satisfy the extreme working conditions ...
• #### The maximum angle condition is not necessary for convergence of the finite element method ﻿

(Numerische Mathematik, 2012-12-31)
We show that the famous maximum angle condition in the finite element analysis is not necessary to achieve the optimal convergence rate when simplicial finite elements are used to solve elliptic problems. This condition ...
• #### The Modellers' Halting Foray into Ecological Theory: Or, What is This Thing Called 'Growth Rate'? ﻿

(Acta Biotheoretica, 2015-12-31)
This discussion paper describes the attempt of an imagined group of non-ecologists ("Modellers" ) to determine the population growth rate from field data. The Modellers wrestle with the multiple definitions of the growth ...
• #### Time-Domain Goal-Oriented Adaptivity Using Pseudo-Dual Error Representations ﻿

(Computer Methods in Applied Mechanics and Engineering, 2017-12)
Goal-oriented adaptive algorithms produce optimal grids to solve challenging engineering problems. Recently, a novel error representation using (unconventional) pseudo-dual problems for goal-oriented adaptivity in the ...
• #### Time-resolved Adaptive Direct FEM Simulation of High-lift Aircraft Configurations ﻿

(Numerical simulation of the aerodynamics of high-lift configurations, 2017-08-01)
Our simulation methodology is referred to as Direct FEM Simulation (DFS), or General Galerkin (G2) and uses a finite element method (FEM) with piecewise linear approximation in space and time, and with numerical stabilization ...
• #### Time-resolved adaptive FEM simulation of the DLR-F11 aircraft model at high Reynolds number ﻿

(52nd AIAA Aerospace Sciences Meeting - AIAA Science and Technology Forum and Exposition, SciTech 2014, 2014-12-31)
We present a time-resolved, adaptive finite element method for aerodynamics, together with the results from the HiLiftPW-2 workshop, where this method is used to compute the ow past a DLR-F11 aircraft model at realistic ...
• #### Towards a parameter-free method for high Reynolds number turbulent flow simulation based on adaptive finite element approximation ﻿

(Computer Methods in Applied Mechanics and Engineering, 2015-05-01)
This article is a review of our work towards a parameter-free method for simulation of turbulent flow at high Reynolds numbers. In a series of papers we have developed a model for turbulent flow in the form of weak solutions ...