Andres Valdez

Andres Valdez
Pennsylvania State University | Penn State

Doctor of Philosophy
I am interested in extending bridges between experimental observations and numerical simulations.

About

15
Publications
4,605
Reads
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40
Citations
Citations since 2016
13 Research Items
40 Citations
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Introduction
Most of my time I work with computational micro-biology. During my Ph.D. I worked with uncertainty quantification for petroleum engineering, During my entire academic life, I used numerical simulations to explain physics. I learned about numerical analysis as well as model validation. If you use simulations and do not know why there is a mismatch with your observed data, drop me an email.
Additional affiliations
October 2021 - present
Pennsylvania State University
Position
  • PostDoc Position
Description
  • Propose and compare models of bacterio-phage growth
September 2017 - September 2021
Federal University of Juiz de Fora
Position
  • PhD Student
Description
  • During my Ph.D. project, I studied and compared efficient Uncertainty Quantification and Sensitivity Analysis methods applied to foam dynamics for Oil Recovery.
September 2016 - September 2017
Federal University of Juiz de Fora
Position
  • Master's Student
Description
  • My Master's dissertation can be found here https://repositorio.ufjf.br/jspui/handle/ufjf/6104

Publications

Publications (15)
Article
Foam injection in porous media is often used to control the gas fingering in multi-phase flow. Mathematical models of foam dynamics involve non-Newtonian formulations. To numerically simulate these complex phenomena, experimental data is gathered and used to estimate the parameter values of models via optimization techniques. The present work impro...
Article
Full-text available
Paper-based microfluidics has grown continuously over the last few years. One of the most important characteristics of paper-based microfluidic devices is the ability to pump fluids with the single action of capillary forces. However, fluid flow control in paper-based microfluidic devices has been studied primarily through empirical approaches; and...
Thesis
Full-text available
Like many other engineering applications, oil recovery and enhanced oil recovery are sensitive to the correct administration of economic resources. Pilot tests and core flood experiments are crucial elements to design an enhanced oil recovery (EOR) project. In this direction, numerical simulators are accessible alternatives for evaluating different...
Article
Full-text available
Uncertainty quantification and sensitivity analysis are crucial tools in the development and evaluation of mathematical models. In enhanced oil recovery, the co-injection of foam in porous media has been investigated through laboratory experiments and mathematical models as a promising technique for improving sweep efficiency. In this work, we stud...
Article
Full-text available
In this work we present a multiscale model to characterize the constitutive behavior of a macro scale fluid accounting micro scale convective, transient and obstacle effects. With the concept of Representative Volume Element (RVE), we perform computational homogenization of several scenarios accentuating the capabilities of the proposed two scale m...
Article
Computer simulations are usually employed for the prediction of oil reservoir performance under different extraction scenarios. Computational model parameters are adjusted to petrophysical properties of the reservoir and production data to forecast production profiles. However, some key features of these models, such as relative permeabilities of w...
Thesis
Full-text available
This work presents computational modeling aspects for studying Fluid-Structure Interaction (FSI). The Lattice Boltzmann Method (LBM) is employed to solve the fluid mechanics considering the incompressible Navier-Stokes equations. The flows studied are complex due to the presence of arbitrary shaped obstacles. The obstacles alters the bulk flow addi...
Article
Full-text available
This article reports an efficient method to characterize constitutive responses based on multiscale modeling for fluid flow in heterogeneous media based on the concept of representative volume element (RVE). Between different scales, it is considered as the basic principles for down-scaling information the conservation of velocity and of the strain...
Conference Paper
Full-text available
This article describes a homogenization procedure based on Multiscale analysis. Such ho-mogenization techniques are important for computer-modeling of heterogeneous materials when the het-erogeneities measures allows us to have separation of scales. Multiscale analysis is a reliable technique to understand material responses in where the micro stru...
Conference Paper
Full-text available
We present a method for understanding Fluid Structure Interaction simulations in continuous media, an important class of phenomena that cover several fields of applications and research lines. Specialized literature has experienced a compelling need for improving the predictive skills of the models for simulations of fluid flow under arbitrary boun...
Conference Paper
Full-text available
This work addresses the multiscale modeling of fluid flow in highly involved media based on the concept of Representative Volume Element. Between scales we consider as basic principles for downscaling information the conservation of the velocity vector field and the conservation of the strain rate tensor field. In this context we formulate (i) the...
Conference Paper
Full-text available
Palabras Clave: Elasticidad Bidimensional, Rotación Nodal Libre, Optimización topológica, Derivada topológica. Resumen. Los elementos finitos clásicos utilizados en la resolución de la ecuación de elasticidad en estado plano no incorporan en su formulación, como grado de libertad, a la rotación de sus nodos; sino que esta rotación puede ser calcula...

Questions

Questions (2)
Question
I am developing a FEM code, and in this case I am trying to define everything in the mesh file, I mean: domains, boundaries, properties of domains, etc, everything that involves problem settings. See the following *.geo file:
Point(1) = {0, 0, 0, 1.0}; Point(2) = {1, 0, 0, 1.0}; Point(3) = {1, 1, 0, 1.0}; Point(4) = {0, 1, 0, 1.0}; Point(5) = {0, 0.5, 0, 1.0}; Point(6) = {1, 0.5, 0, 1.0}; Line(1) = {1, 2}; Line(2) = {2, 6}; Line(3) = {6, 3}; Line(4) = {3, 4}; Line(5) = {4, 5}; Line(6) = {5, 1}; Line(7) = {5, 6}; Line Loop(8) = {4, 5, 7, 3}; Plane Surface(9) = {8}; Line Loop(10) = {7, -2, -1, -6}; Plane Surface(11) = {10}; Physical Surface('top') = {9}; Physical Surface('bottom') = {11};
I am moving forward tryinig to understand if it is possible to give each domain characteristics to the physical entities defined in the *.geo file. It is my intention to write in the *.geo file the aforementioned definitions. Is this possible to do?
Question
Good afternoon i am trying to generate a rectangular (2d) mesh with GMSH. In the mesh I am placing"n-random" circles or ellipses, with out overlapping. I would like to know if this is possible to be done in GMSH? and if so I would like some hints on how to do it.
Thanks for the provided answers.-

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Projects

Project (1)
Project
Development of analytical solutions for oil spreading problems that is appropriate for foam generation including resolution of the Riemann problem for this model along with solutions in the form of traveling waves.