Flujo de Poiseuille y la cavidad con pared móvil calculado usando el método de la ecuación de lattice Boltzmann

AbstractThe aim of this article is to present the results of the lattice Boltzmann method (LBM) application as computational fluid dynamics solvers. After of short review of the basic theory and using the two-dimensional model with 9 velocities (D2Q9), the Poiseuille flow is modelled and validated the results with the analytical solutions. Also, the Lid-driven cavity is modelled and validated the results with existing data (Guía et al.). The boundary condition for static wall and moving wall are revised on the first and second model respectively. The results indicate the efficiency of LBM to simulate incompressible and laminar fluid flow. Also, that the effects of increment in the number of the lattice points, improve the computational convergence and reduce spatial oscillations of solution near geometrically singular points in the flow.ResumenEl objetivo de este artículo es presentar los resultados de la aplicación del Método de Lattice Boltzmann (LBM) como una herramienta de solución en la dinámica computacional de fluidos. Después de una corta revisión de la teoría básica y utilizando el modelo bidimensional de 9 velocidades (D2Q9), el flujo de Poiseuille es simulado y los resultados son comparados con la solución analítica existente. También, es modelada la cavidad con pared móvil (Lid-driven) y los resultados obtenidos validados con datos existentes (Guía et al.). Las condiciones de frontera para pared estática y pared móvil son revisadas en el primer y segundo modelo, respectivamente. Los resultados indican la eficiencia del LBM para simular flujos de fluido incompresibles y laminares. También, que como efecto de incrementar el número de puntos en el lattice, mejora la convergencia computacional y reduce las oscilaciones espaciales de la solución cerca de puntos geométricamente singulares en el flujo

Poiseuille flow and the lid-driven cavity calculate using the Lattice Boltzmann equation method

ResumenEl objetivo de este artículo es presentar los resultados de la aplicación del Método de Lattice Boltzmann (LBM) como una herramienta de solución en la dinámica computacional de fluidos. Después de una corta revisión de la teoría básica y utilizando el modelo bidimensional de 9 velocidades (D2Q9), el flujo de Poiseuille es simulado y los resultados son comparados con la solución analítica existente. También, es modelada la cavidad con pared móvil (Lid-driven) y los resultados obtenidos validados con datos existentes (Guía et al.). Las condiciones de frontera para pared estática y pared móvil son revisadas en el primer y segundo modelo, respectivamente. Los resultados indican la eficiencia del LBM para simular flujos de fluido incompresibles y laminares. También, que como efecto de incrementar el número de puntos en el lattice, mejora la convergencia computacional y reduce las oscilaciones espaciales de la solución cerca de puntos geométricamente singulares en el flujo.AbstractThe aim of this article is to present the results of the lattice Boltzmann method (LBM) application as computational fluid dynamics solvers. After of short review of the basic theory and using the two-dimensional model with 9 velocities (D2Q9), the Poiseuille flow is modelled and validated the results with the analytical solutions. Also, the Lid-driven cavity is modelled and validated the results with existing data (Guía et al.). The boundary condition for static wall and moving wall are revised on the first and second model respectively. The results indicate the efficiency of LBM to simulate incompressible and laminar fluid flow. Also, that the effects of increment in the number of the lattice points, improve the computational convergence and reduce spatial oscillations of solution near geometrically singular points in the flow

Analysis of Aeroacoustic Properties of the Local Radial Point Interpolation Cumulant Lattice Boltzmann Method

The lattice Boltzmann method (LBM) has recently been used to simulate wave propagation, one of the challenging aspects of wind turbine modeling and simulation. However, standard LB methods suffer from the instability that occurs at low viscosities and from its characteristic lattice uniformity, which results in issues of accuracy and computational efficiency following mesh refinement. The local radial point interpolation cumulant lattice Boltzmann method (LRPIC-LBM) is proposed in this paper to overcome these shortcomings. The LB equation is divided into collision and streaming steps. The collision step is modeled by the cumulant method, one of the stable LB methods at low viscosities. In addition, the streaming step, which is naturally a pure advection equation, is discretized in time and space using the Lax–Wendroff scheme and the local radial point interpolation method (RPIM), a mesh free method. We describe the propagation of planar acoustic waves, including the temporal decay of a standing plane wave and the spatial decay of a planar acoustic pulse. The analysis of these specific benchmark problems has yielded qualitative and quantitative data on acoustic dispersion and dissipation, and their deviation from analytical results demonstrates the accuracy of the method. We found that the LRPIC-LBM replicates the analytical results for different viscosities, and the errors of the fundamental acoustic properties are negligible, even for quite low resolutions. Thus, this method may constitute a useful platform for effectively predicting complex engineering problems such as wind turbine simulations, without parameter dependencies such as the number of points per wavelength Nppw and resolution σ or the detrimental effect caused by the use of coarse grids found in other accurate and stable LB models

Analysis of Aeroacoustic Properties of the Local Radial Point Interpolation Cumulant Lattice Boltzmann Method

The lattice Boltzmann method (LBM) has recently been used to simulate wave propagation, one of the challenging aspects of wind turbine modeling and simulation. However, standard LB methods suffer from the instability that occurs at low viscosities and from its characteristic lattice uniformity, which results in issues of accuracy and computational efficiency following mesh refinement. The local radial point interpolation cumulant lattice Boltzmann method (LRPIC-LBM) is proposed in this paper to overcome these shortcomings. The LB equation is divided into collision and streaming steps. The collision step is modeled by the cumulant method, one of the stable LB methods at low viscosities. In addition, the streaming step, which is naturally a pure advection equation, is discretized in time and space using the Lax–Wendroff scheme and the local radial point interpolation method (RPIM), a mesh free method. We describe the propagation of planar acoustic waves, including the temporal decay of a standing plane wave and the spatial decay of a planar acoustic pulse. The analysis of these specific benchmark problems has yielded qualitative and quantitative data on acoustic dispersion and dissipation, and their deviation from analytical results demonstrates the accuracy of the method. We found that the LRPIC-LBM replicates the analytical results for different viscosities, and the errors of the fundamental acoustic properties are negligible, even for quite low resolutions. Thus, this method may constitute a useful platform for effectively predicting complex engineering problems such as wind turbine simulations, without parameter dependencies such as the number of points per wavelength Nppw and resolution σ or the detrimental effect caused by the use of coarse grids found in other accurate and stable LB models

Mesenchymal Stromal Cells for Treating Steroid-Resistant Acute and Chronic Graft Versus Host Disease: A Multicenter Compassionate Use Experience

Graft versus host disease (GVHD) is a severe complication after allogenic hematopoietic cell transplantation (HSCT). Several clinical trials have re ported the use of mesenchymal stromal cells (MSCs) for the treatment of GVHD. In March 2008, the Andalusian Health Care System launched a compassionate use program to treat steroid-resistant GVHD with MSC. Clinical-grade MSC were obtained under GMP conditions. MSC therapy was administered intravenously in four separate doses of 1 × 106 cells/kg. Sixty-two patients, 45 males (7 children) and 17 females (2 children), received the treatment. Patients had a median age of 39 years (range: 7–66) at the time of the allogenic HSCT. The overall response was achieved in 58.7% of patients with acute (a)GVHD. Two years’ survival for aGVHD responders was 51.85%. The overall response for patients with chronic (c)GVHD was 65.50% and the 2-year survival rate for responders was 70%. Age at the time of HSCT was the only predictor found to be inversely correlated with survival in aGVHD. Regarding safety, four adverse events were reported, all recovered without sequelae. Thus, analysis of this compassionate use experience shows MSC to be an effective and safe therapeutic option for treating refractory GVHD, resulting in a significant proportion of patients responding to the therapy

Mesenchymal Stromal Cells for Treating Steroid-Resistant Acute and Chronic Graft Versus Host Disease: A Multicenter Compassionate Use Experience.

Graft versus host disease (GVHD) is a severe complication after allogenic hematopoietic cell transplantation (HSCT). Several clinical trials have reported the use of mesenchymal stromal cells (MSCs) for the treatment of GVHD. In March 2008, the Andalusian Health Care System launched a compassionate use program to treat steroid-resistant GVHD with MSC. Clinical-grade MSC were obtained under GMP conditions. MSC therapy was administered intravenously in four separate doses of 1 × 106 cells/kg. Sixty-two patients, 45 males (7 children) and 17 females (2 children), received the treatment. Patients had a median age of 39 years (range: 7-66) at the time of the allogenic HSCT. The overall response was achieved in 58.7% of patients with acute (a)GVHD. Two years' survival for aGVHD responders was 51.85%. The overall response for patients with chronic (c)GVHD was 65.50% and the 2-year survival rate for responders was 70%. Age at the time of HSCT was the only predictor found to be inversely correlated with survival in aGVHD. Regarding safety, four adverse events were reported, all recovered without sequelae. Thus, analysis of this compassionate use experience shows MSC to be an effective and safe therapeutic option for treating refractory GVHD, resulting in a significant proportion of patients responding to the therapy

Proyecto Verbum

Se desarrolla un proyecto de innovación educativa que pretende incrementar el número de lecturas efectuadas por el alumnado tomando como referencia los años anteriores, alcanzando un grado de disfrute de la propia actividad de leer. Para motivar el hábito de leer se procura vincular los contenidos de los textos a leer a los intereses y preocupaciones del alumnado, proporcionando un listado y son ellos mismos quines elige sus lecturas. Se trata de concienciar ala alumnado de que la lectura y el buen uso de la lengua son instrumentos fundamentales para su desarrollo personal y educativo. El proyecto pretende a su vez implicar a los familiares en el proceso educativo de sus hijos o hijas, abriendo nuevas vías de comunicación entre las personas y propiciando encuentros entre lectores, ya sean presenciales o a través de la red. A través de las Nuevas Tecnologías se pretende ampliar las posibilidades técnicas en las actividades lectoras. El profesorado presenta los argumentos, acciones o personajes de los libros de lectura a elegir para que elija el que prefiera. El alumnado una vez leído el libro elegido, realiza un comentario del texto e invita a sus compañeros y compañeras a leerlo si así lo cree conveniente a modo de consejo. Los alumnos y alumnas que han leído un mismo libro preparan en grupo una exposición ante el resto de la clase, del contenido del libro, de sus impresiones, valoraciones y estructura. El profesorado de las diferentes áreas advierte al alumnado los contenidos relacionados en la lectura con su materia y les proporciona información adicional que les permita sacar el máximo provecho de la lectura. En el centro se han desarrolla actividades extraescolares y complementarias como encuentros con escritores, exposiciones sobre autores y obras, recitales de poesía, lecturas dramatizadas. La valoración general del proyecto tanto por parte del profesorado como del alumnado se es positiva, a pesar de las dificultades generadas.Castilla y LeónConsejería de Educación. Dirección General de Universidades e Investigación; Monasterio de Nuestra Señora de Prado, Autovía Puente Colgante s. n.; 47071 Valladolid; +34983411881; +34983411939ES