Parametric study of the interface behavior between two immiscible liquids flowing through a porous medium

When two immiscible liquids that coexist inside a porous medium are drained through an opening, a complex flow takes place in which the interface between the liquids moves, tilts and bends. The interface profiles depend on the physical properties of the liquids and on the velocity at which they are extracted. If the drainage flow rate, the liquids volume fraction in the drainage flow and the physical properties of the liquids are known, the interface angle in the immediate vicinity of the outlet (theta) can be determined. In this work, we define four nondimensional parameters that rule the fluid dynamical problem and, by means of a numerical parametric analysis, an equation to predict theta is developed. The equation is verified through several numerical assessments in which the parameters are modified simultaneously and arbitrarily. In addition, the qualitative influence of each nondimensional parameter on the interface shape is reported.Comment: 7 pages, 12 figure

Simulación de la migración de hidrógeno en aleaciones de zirconio

En este trabajo se estudia el fenómeno de migración de hidrógeno y formación de blisters de hidruro ante el contacto entre tubos de presión y tubos calandria en reactores tipo CANDU. Este fenómeno es actualmente admitido como uno de los principales factores limitantes de la vida Útil de este tipo de reactores, desde que ocasionara el incidente de Pickering en 1983. Se desarrolla un método numérico basado en la regularización de las ecuaciones constitutivas que, con el tratamiento usual de elementos finitos y con un esquema de Newton-Raphson, permite resolver el citado problema sobre redes generales. Se incluyen resultados unidimensionales y bidimensionales, que muestran buen acuerdo con soluciones cuasi-analíticas disponibles (caso l-D) e ilustran la capacidad del método empleado.Peer Reviewe

A two-component fluid-solid finite element model of the red blood cell

The state of the art models for the red blood cell consist of two components: A solid network of fibers (worm-like chains) that correspond to the cytoskeleton, and a fluid surface with bending stiffness that corresponds to the lipid bilayer (X. Li et.al., Phil. Trans. R. Soc. A, 372:20130389 (2014)). The fluid and solid components are connected at the junctions of the network, where trans-membrane proteins anchor the bilayer to the cytoskeleton, but this connection is not rigid and under large deformations it is possible that cytoskeleton and bilayer detach from one another. It is well know that the interactions between the lipid bilayer membrane and the skeletal network (fluid-solid interactions) are responsible for the physical properties of red blood cell. However, quantifying these interactions and studying the related dynamics is still a topic discussed and full of open questions (S. Lux, Blood, 127:187–199 (2016)). In this work we will report on our first advances towards the development of a finite element method for this strongly coupled system. It leads to a fluid-structure interaction problem, with the salient feature that both the fluid and the structure are in fact two-dimensional bodies evolving in three-dimensional space.Publicado en: Mecánica Computacional vol. XXXV, no. 9.Facultad de Ingenierí

A two-component fluid-solid finite element model of the red blood cell

The state of the art models for the red blood cell consist of two components: A solid network of fibers (worm-like chains) that correspond to the cytoskeleton, and a fluid surface with bending stiffness that corresponds to the lipid bilayer (X. Li et.al., Phil. Trans. R. Soc. A, 372:20130389 (2014)). The fluid and solid components are connected at the junctions of the network, where trans-membrane proteins anchor the bilayer to the cytoskeleton, but this connection is not rigid and under large deformations it is possible that cytoskeleton and bilayer detach from one another. It is well know that the interactions between the lipid bilayer membrane and the skeletal network (fluid-solid interactions) are responsible for the physical properties of red blood cell. However, quantifying these interactions and studying the related dynamics is still a topic discussed and full of open questions (S. Lux, Blood, 127:187–199 (2016)). In this work we will report on our first advances towards the development of a finite element method for this strongly coupled system. It leads to a fluid-structure interaction problem, with the salient feature that both the fluid and the structure are in fact two-dimensional bodies evolving in three-dimensional space.Publicado en: Mecánica Computacional vol. XXXV, no. 9.Facultad de Ingenierí

A two-component fluid-solid finite element model of the red blood cell

The state of the art models for the red blood cell consist of two components: A solid network of fibers (worm-like chains) that correspond to the cytoskeleton, and a fluid surface with bending stiffness that corresponds to the lipid bilayer (X. Li et.al., Phil. Trans. R. Soc. A, 372:20130389 (2014)). The fluid and solid components are connected at the junctions of the network, where trans-membrane proteins anchor the bilayer to the cytoskeleton, but this connection is not rigid and under large deformations it is possible that cytoskeleton and bilayer detach from one another. It is well know that the interactions between the lipid bilayer membrane and the skeletal network (fluid-solid interactions) are responsible for the physical properties of red blood cell. However, quantifying these interactions and studying the related dynamics is still a topic discussed and full of open questions (S. Lux, Blood, 127:187–199 (2016)). In this work we will report on our first advances towards the development of a finite element method for this strongly coupled system. It leads to a fluid-structure interaction problem, with the salient feature that both the fluid and the structure are in fact two-dimensional bodies evolving in three-dimensional space.Publicado en: Mecánica Computacional vol. XXXV, no. 9.Facultad de Ingenierí