Abraham Medina

Experimental and Computational Fluid Mechanics

In this work, the stability of a strongly non-parallel symmetrical counterflow mixed convection problem is studied, using numerically generated eigenfunctions. The base flow is numerically obtained for each value of the buoyancy parameter (Richardson number), and the stability of this flow is analyzed by increasing its value while all the others remained fixed. The perturbed linear functions are numerically generated by introducing a transient modulated asymmetrical buoyancy, relaxing at later times to ‘numerical eigenfunctions’. The time evolution of the amplitude of these perturbations is used to obtain the stability characteristics. Symmetry breaking instability occurs, for fixed geometry, Reynolds and Prandtl numbers, for values of the buoyancy parameter larger than a critical one. However, there is also a window for the buoyancy parameter below this critical value, where the system shows instability, producing a slightly asymmetric thermal and flow response.

Equilibrium height of a liquid in a gap between corrugated walls under spontaneous capillary penetration.

A simple and general method is presented to calculate the equilibrium surface of a liquid that penetrates spontaneously, due to capillarity, in the gap between two vertical corrugated plates. Several properties of the equilibrium solution are discussed and the results are backed by a qualitative experiment.

Experimental Study of Mass Flow Rate in a Silo Under the Wall Width Influence

The mass flow rate, \(\dot{m}\), associated with the lateral outflow of dry, cohesionless granular material through circular orifices of diameter \(D\) made in vertical walls of silos was measured experimentally in order to determine also the influence of the wall thickness of the silo, \(w\). Geometrical arguments, based on the outflow happening, are given in order to have a general correlation for \(\dot{m}\) embracing both quantities, \(D\) and \(w\). The angle of repose appears to be an important characterization factor in these kinds of flows.

Fluid Dynamics in Physics, Engineering and Environmental Applications

The objective of this chapter is to review the importance of fluid dynamics research and its impact on science and technology. Here we consider four particular areas of study, namely environmental fluid mechanics, turbulence, nanoand microfluids, and biofluid dynamics, with deeper emphasis on environmental flows. Each of these topics is illustrative of how improved scientific knowledge of fluid dynamics can have a major impact on important national needs and worldwide economies, as well as help developed nations to maintain their leadership in the production of novel technologies. J. Klapp (&) Instituto Nacional de Investigaciones Nucleares, ININ, Km. 36.5, Carretera México-Toluca, 52750 La Marquesa, Estado de México, Mexico e-mail: jaime.klapp@hotmail.com J. Klapp Departamento de Matemáticas, Cinvestav del I.P.N., 07360 México, D.F., Mexico L. D. G. Sigalotti L. Trujillo Centro de Física, Instituto Venezolano de Investigaciones Científicas, IVIC, Apartado Postal 20632, 1020 Caracas, Venezuela e-mail: leonardo.sigalotti@gmail.com L. Trujillo e-mail: leonardo.trujillo@gmail.com L. Trujillo The Abdus Salam, International Centre for Theoretical Physics, ICTP, Trieste, Italy C. Stern Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, C. Exterior s/n, 04510 Coyoacán, D.F., Mexico e-mail: catalina@ciencias.unam.mx J. Klapp et al. (eds.), Fluid Dynamics in Physics, Engineering and Environmental Applications, Environmental Science and Engineering, DOI: 10.1007/978-3-642-27723-8_1, Springer-Verlag Berlin Heidelberg 2013 3In this work we study the tertiary structure of ionic surfactants when the pH in the system is modified using electrostatic dissipative particle dynamics simulations (DPD). The dependence with pH and kind of surfactant is presented. Our simulations reproduce the experimental behavior reported in the literature. The scaling for the radius of gyration with the size of the molecule as a function of pH is also obtained.

Visualization of steam injection into homogeneous porous media

In this study we describe the important features of the process of steam injection through non-consolidated porous media made of sand. We have analyzed the resulting fluid flow patterns through normal and infrared visualization by varying the injection pressure into a horizontal cylindrical pipe and a circular cell on a vertical position. Such configurations mimic those occurring under the steam assisted gravity drainage (SAGD) in tertiary recovery from oilfields and geothermal reservoirs. We describe some characteristics of the ubiquitous condensation front in both experimental arrays. In the first case, a glass pipe filled with sand was subjected to steam injection at different pressures. In the second case, a circular cell on a vertical position brimful of sand cell was subjected to similar processes. For each case, the existence of several types of condensation fronts, depending on the injection pressure, has been evidenced by means of digital and infrared visualization which gives mutually complementary information.Graphical abstract

Super Free Fall of a Liquid Frustum in a Semi-infinite Cone

In this paper we have analyzed theoretically the super free fall of a near inviscid mass of liquid, which fills partially a small section of a very long vertical conical pipe. Through the use of a one-dimensional inviscid model, we describe the simultaneous and pecular motion of the two interphases of the liquid.

Trajectories of Water and Sand Jets

In this paper we introduce a correlation for the trajectories of sand jets, of a non-cohesive granular material, emerging from vertical sidewall orifices of diameter D and wall thickness w. A contrast with water jet in similar configurations has been performed. We found that the theoretical trajectories agree well with the experimental ones.

Recent Advances in Fluid Dynamics with Environmental Applications

In the present work, the laminar steady state fluid dynamics and heat transfer, in a two-dimensional open cavity with a cross flow due to a secondary jet injected at the top wall, are analyzed. The numerical study is carried out for a Reynolds number of 500 with different Richardson and Prandtl numbers. A hot plate is provided on the bottom of the cavity which generates the heating of the fluid. In order to investigate the effect of the length of the plate two different plate sizes are considered. The governing equations of continuity, momentum and energy for incompressible flow are solved by the finite element method combined with the splitting operator scheme. It is studied the streamlines and isotherms inside the cavity and it is analyzed the average Nusselt number, the average temperature and the outlet temperature as a function of the Richardson and Prandtl numbers. It is observed that the Prandtl and Richardson numbers play a major role in the thermal and fluid behavior of the flow inside the cavity with a cross flow. Moreover the results indicate that a secondary jet injected at the top wall enhances the average Nusselt number. G.E. Ovando-Chacon (✉) ⋅ J.C. Prince-Avelino ⋅ A. Rodriguez-León ⋅ A. Servin-Martínez Depto. de Metal Mecánica Y Mecatrónica, Instituto Tecnológico de Veracruz, Calzada Miguel A. de Quevedo 2779, Col. Formando Hogar, 91860 Veracruz, Mexico e-mail: geoc@itver.edu.mx J.C. Prince-Avelino e-mail: jcpa@itver.edu.mx A. Rodriguez-León e-mail: arleon@itver.edu.mx A. Servin-Martínez e-mail: alservinm@gmail.com S.L. Ovando-Chacon Depto. de Química Y Bioquímica, Instituto Tecnológico de Tuxtla Gutiérrez, Carretera Panamericana Km. 1080, Tuxtla Gutiérrez, Chiapas, Mexico e-mail: ovansandy@hotmail.com

Visualization of isotherms around a heated horizontal cylinder embedded in a porous medium

Experiments reported here confirm experimentally the existence of the characteristic planar buoyant plumes that emerge as a consequence of the presence of a cylindrical heat source embedded in an homogeneous air-saturated and non-consolidated porous medium. The resultant buoyant plumes were visualized with IR thermography considering two important cases. First, under the action of natural convection and second, under the action of forced convection due to the passage of a constant air stream directed perpendicularly towards the horizontal cylindrical heat source buried in the porous medium. Such streams were induced at different tilt angles. For each case, the temperature distribution is shown and correspondence is found with the isotherms distribution predicted by the theoretical models reported in the literature. The use of infrared techniques appears as a helpful tool that allows us to witness all the process of rise and growth of the buoyant plumes until the phenomenon reaches steady state.Graphical abstract

Isotherms of Natural and Forced Convection Around a Heated Horizontal Cylinder Embedded in a Porous Medium

This work presents an experimental analysis of free and forced convection due to a heated cylinder in a fluid-saturated porous medium. The resulting features of the temperature distribution under the action of a continuous and uniform air stream were investigated through the use of four different configurations: first, by inducing an air stream from below the heated cylinder; second, by placing an air stream on the left-hand side of the heat source; third by an air stream acting from the top of the heat source, and fourth by varying the injection angle. The consequences on the free and forced convection when all phenomena reach the steady state were analyzed by using an infrared camera. Close agreement is found through the conformed plumes with the theoretical solutions proposed by Kurdyumov and Linan (2001).