Proyectos realizados
Visualization of currents inside an oscillating
Autores: Rangel Paredes Gerardo, Porta Zepeda David, Echeverría Arjonilla Carlos, Stern Forgach Catalina.
This fluid dynamics video shows an oscillating water drop forced vertically at 60Hz. If the video is taken at 3200fps, the underlying geometrical structure can be observed. If the video is taken at 60fps structure is not detected. However, if a drop of dye is injected on one side, the presence of currents inside the drop can be observed even at 60fps. If the dye is injected on the top, an unexpected geometrical stationary pattern is observed. After more than 50secs, the drop seems to react to the increase in volume, and the pattern changes completely. Finally, a similar drop at the same frequency is visualized using toner powder, the underlying currents appear clearly.
Shadowgraph of a miscible drop falling in a stratified fluid
Autores: Zarazua Cruz Angelica, Echeverría Arjonilla Carlos, Porta Zepeda David, Stern Forgach Catalina.
In this video for the Gallery of Fluid Motion we show a partially miscible drop (Benzyl alcohol) as it falls through a stratified fluid. Two different visualization techniques are used: direct and focused shadowgraph. First the free fall in pure water is observed and the wake behind the drop is clearly visualized, indicating that the material is Benzyl alcohol. As the drop approaches the interface, it flattens. The drop is finally trapped at the interface where it has a damped oscillation. The focused shadowgraph has an excellent spatial resolution.
Visualización de la inestabilidad de Kelvin-Helmholtz con bióxido de carbono y aire
Autores: Amezcua Montiel Abril,Sánchez Reséndiz Saúl, Zamarrón Ramírez Javier.
Se analiza y observa experimentalmente el crecimiento de las inestabilidades de Kelvin-Helmholtz (K-H) en la interfaz de CO2 y aire al crearse un gradiente de velocidades. Esta diferencia de velocidades entre ambas capas se forma al desplazar una película delgada de jabón entre ellas. Se encontró en promedio un número de Richardson de -1.59 lo cual indica, como se esperaba, que el sistema presenta inestabilidad. También se obtuvieron una serie de videos donde se aprecian las inestabilidades K-H, así como el rompimiento de la película de jabón sobre la superficie de una pecera.
Visualización de la Magnetohidrodinámica
Autores: Carolina Itzel Juárez Juárez y Luis Angel Flores Aguario.
En este trabajo se aprecia de manera visual los modelos teóricos de la aplicación de un campo eléctrico a una capa delgada de electrolito bajo la influencia de campos magnéticos no uniformes, constantes y localizados, para después de esto varias las condiciones y poder ofrecer resultados cualitativos para diferentes configuraciones.
Visualization of Vortices formed by different Nozzle Geometries
Autores: León Paola, Echeverría Carlos, Porta David, Stern Catalina.
In this work we show a visualization of vortices generated by nozzles of different geometries (circular, flat and triangular). This was done both in a lateral view and in various frontal cross sections along the trajectory of each vortex. It is observed that the vortices generated by the flat and triangular nozzles tend to evolve to a circular vortex, even when they seem unstable along the path. For the flat nozzle, the vortex tends to be axisymmetric after 51mm and for the triangular nozzle after 61 mm. In the frontal view we observed that the internal structure of the vortices is very complicated, apparently smaller vortices of different sizes are generated and destroyed.
Tubo de Kundt. Velocidad del sonido
Autores: Ortiz Luis, Espinosa Dante.
En éste trabajo experimental se ve el comportamiento de las ondas acústicas en el tubo de Kundt. El sonido son ondas longitudinales, el tubo de Kundt es una guía de ondas que permite visualizar qué es el sonido. Se hace notar que el sonido es una perturbación en el aire, de hecho, son cambios de presión. Sabiendo esto, se ha podido realizar cambios de presión en el tubo y propagar una onda para observar que cambia su frecuencia. Objetivos: 1. Analizar la propagación de ondas acústicas en el tubo de Kundt. 2. Determinar la velocidad del sonido en el aire. 3. Visualizar el fenómeno de resonancia. 4. Observar el comportamiento de las ondas acústicas al cambiar la presión del medio de propagación.
Dynamical behavior of an oscillating drop
Autores: Flores Fátima, Haro Flor, Rangel Gerardo, Echeverría Arjonilla Carlos, Porta Zepeda David, Catalina E. Stern Forgach.
In the present paper the dynamic behavior of a drop of water subject to a vertical oscillating force is studied experimentally. A hydrophobic surface was used to maintain the form of the drop. The deformation of the drop as a response to several frequencies was analyzed by visualizing the oscillating patterns and measuring the maximum height of the drop as a function of time. The dynamic behavior has been classified in three phases: harmonic, geometric and chaotic.
Critical phenomena of a drop crossing a stratified fluid
Autores: Álvarez González Verónica, Zarazúa Cruz Angelica, Echeverría Arjonilla Carlos, Porta Zepeda David, Stern Forgach E. Catalina.
The present paper describes the dynamics of a drop as it falls through a stratified fluid with two layers. As it enters the fluid, the drop forms an annular vortex that different deformation processes depending on the conditions of the experiment. In this work, the only variables that have been modified are the density of the drop and the height of the upper fluid. Images of the phenomena were taken directly with a high speed camera and with a shadowgraph set-up.
Interacción de vórtices anulares con distintas mallas
Autores: Delgado Jiménez Nadxiieli, Santa Rita Alcibia Pedro H., Trejo Gutiérrez J. Antonio, Echeverría Arjonilla Carlos, Porta Zepeda David, Catalina E. Stern Forgach.
...
Flow visualization inside a Ranque Hilsch tube
Autores: Porta Zepeda David, Echeverría Arjonilla Carlos, Stern Forgach Elizabeth Catalina.
In this fluid dynamics video we visualize the flow inside a Ranque-Hilsch tube either with baby powder or with water. A Ranque-Hilsch tube is a mechanical device that, without any moving components, separates a stream of gas into a hot and a cold components. The physical phenomenon has not been completely understood.
Shadowgraph of a miscible drop falling in a stratified fluid
Autores: Zarazúa Cruz Angelica, Echeverría Arjonilla Carlos, Porta Zepeda David, Stern Forgach Catalina
In this video for the Gallery of Fluid Motion we show a partially miscible drop (Benzyl alcohol) as it falls through a stratified fluid. Two different visualization techniques are used: direct and focused shadowgraph. First the free fall in pure water is observed and the wake behind the drop is clearly visualized, indicating that the material is Benzyl alcohol. As the drop approaches the interface, it flattens. The drop is finally trapped at the interface where it has a damped oscillation. The focused shadowgraph has an excellent spatial resolution.
Visualization of shock waves emitted from a trumpet bell and their interaction with several objects
Autores: Carlos Echeverría, David Porta Zepeda, Roberto Velasco-Segura Roberto, Pablo L. Rendón, Antonio Pérez-López,Catalina E. Stern.
In this video for the Gallery of Fluid Motion we use a confocal schlieren system to visualize shock waves produced by an actuator through a trumpet bell. This allows us to model the profile of such a wave as it travels after emission. After they exit from the trumpet, we make them interact with various objects. We were able to observe reflection, transmission, attenuation, diffraction and wave-wave interaction.
Visualization of currents inside an oscillating
Autores: Rangel Paredes Gerardo, Porta Zepeda David, Echeverría Arjonilla Carlos, Stern Forgach Catalina.
This fluid dynamics video shows an oscillating water drop forced vertically at 60Hz. If the video is taken at 3200fps, the underlying geometrical structure can be observed. If the video is taken at 60fps structure is not detected. However, if a drop of dye is injected on one side, the presence of currents inside the drop can be observed even at 60fps. If the dye is injected on the top, an unexpected geometrical stationary pattern is observed. After more than 50secs, the drop seems to react to the increase in volume, and the pattern changes completely. Finally, a similar drop at the same frequency is visualized using toner powder, the underlying currents appear clearly.
Proyectos en desarrollo
Vórtices de agua
Autores:
El estudio de los vórtices es muy importante en varios sectores de la ciencia y la tecnología por su capacidad de transferir enormes cantidades de masa y energía. Un fluido tiene vorticidad en regiones donde hay giros locales. Los vórtices son estructuras organizadas que giran. Debido a la conservación del momento angular, los vórtices pueden viajar distancias considerables antes de deshacerse debido a la viscosidad. Un vórtice anular o toroidal se forma cuando el fluido se curva sobre sí mismo y forma un anillo rotatorio. Un caso típico sucede en los anillos formados por los fumadores. En el video se observa un sistema generador de dos vórtices (azul y rojo), con desplazamientos contrarios. Cada colisión frontal tuvo diferentes condiciones de salida.
Kelvin Helmholtz
Autores:
La inestabilidad de Kelvin-Helmholtz se inicia en la interface entre dos corrientes que se mueven a velocidades diferentes. Cuando las condiciones meteorológicas son adecuadas, las nubes pueden servir para visualizar el fenómeno.
Efecto Kaye
Autores:
Los fluidos pseudo plásticos son los que se adelgazan en presencia de esfuerzos de corte. Se ha observado que cuando un chorro de este fluido se vierte sobre una superficie cubierta con el mismo fluido, bajo ciertas condiciones el chorro rebota muy cerca del punto de incidencia. Este fenómeno fue descrito por primera vez por Kaye en 1963. En este experimento se varió el ángulo chorro-superficie y, la altura de caída del líquido; mostrando diferentes condiciones iniciales y de frontera.