Two Phase Flows
One of our main interests is the study of the two-phase flows. For the case of granular flows, the complexity in determining the behavior of these
flows arises from the inelastic and frictional contacts among particles. For bubbly flows, the hydrodynamic interactions among bubbles give rise to velocity fluctuations which, in turn, give a turbulent-like character to these flows. In both cases, there have been significant developments over the last 15 years. My research group has actively participated in the collective effort to understand these systems better. We continue investigating different aspects of these flows, including the effect of non Newtonian rheology in bubbly flows, the transition between viscous and collisional dominated regimes in liquid-solid flows, flow of bubbles in porous media, etc. Progress in this subject is driven by the interest of understanding the fundamental nature of two-phase flows, independently from having direct applications. However, due to their prevalence in many modern engineering applications, there is wide practical interest and many funding opportunities.
Key publications:
- Zenit, R. and Feng, J. J. Hydrodynamic interactions among bubbles, drops and particles in non-Newtonian liquids, Annual Review of Fluid Mechanics, 50, 505-534, 2018.
- Joseph, G.G., Zenit, R., Hunt, M.L. and Rosenwinkel, A., Particle-wall collisions in a viscous fluid , Journal of Fluid Mechanics, 433, 329 – 346, 2001.
- Zenit, R., Koch, D.L. and Sangani, A.K., Measurements of the average properties of a suspension of bubbles rising in a vertical channel, Journal of Fluid Mechanics, 429, 307-342, 2001.
Biological Flows
The understanding of many biological systems cannot be completed without analyzing the fluid motion implied in them. The study of such flows give us an unique opportunity to explain many phenomena from a fundamental point of view. One approach is to study these systems replicating exactly the biological conditions in a controlled environment. A better one is to simplify and model the problems by removing as many layers of complexity as possible, yet retaining the most relevant ones.
Our group has studied the flow-structure interaction in biological heart valve prostheses and the locomotion dynamics of microorganisms in
complex fluids.
Key publications:
- Ledesma-Alonso, R., Guzman, J.E.V. and Zenit, R., Experimental study of a model valve with flexible leaflets in a pulsatile flow. Journal of Fluid Mechanics, 739, 338–362, 2014.
- Palacios-Morales, C.A. and Zenit R., The formation of vortex rings in shear-thinning liquids. Journal of Non Newtonian Fluid Mechanics, 194, 1-13, 2013.
- Gomez, S., Godinez, F.A., Lauga, E. and Zenit, R., Helical propulsion in shear-thinning fluids. Journal of Fluid Mechanics, 812, R3, 2017.
Artistic Painting and Fluid Mechanics
Painting is, essentially a fluid mechanical problem. Much research has been devoted to understand the process of coating a solid surface with a fluid film, since most man-made surfaces are painted. In general, the objective of painting is to cover a solid surface with a thin and uniform layer of paint. For the case of artistic painting this is not exactly the case. Artists aim to create coating textures of aesthetic value to express their views. Hence, they learn to manipulate the fluid and the process in unique ways. They do this in an empirical manner through experimentation and many trial-and-error repetitions. Through a series of recent projects, inspired by art historians, my research group has been involved in the understanding the physical principles of the painting techniques used by famous modern painters. We have studied the accidental painting technique by David Alfaro Siqueiros, the dripping technique by Jackson Pollock and we have many other ongoing projects in this subject.
Key publications:
- Zetina, S. Godinez, F.A. and Zenit, R. A hydrodynamic instability is used to create aesthetically appealing patterns in painting. PLoS ONE, 10, e0126135, 2015.
- Palacios-Muniz, B., Rosario, A. Wilhelmus, M. M., Zetina, S. and Zenit, R., Pollock avoided hydrodynamic instabilities to paint with his dripping technique, PLOS One, 14(10): e0223706, 2019.
Other research subjects
When we encounter an interesting problem, related to fluid mechanics, we cannot say no. We have collaborated with several other research groups to study other subjects, including: flow through porous media, convectice heat transfer, mixing, etc. Please see publication list for a full account of all research interests.
Key publications:
- Beltran, A., Chavez, O., Zaldivar, J., Godinez, F., Garcia, A. and Zenit, R., A new model for the computation of the formation factor of core rocks, Journal of Structural Geology, 97, 189-198, 2017.
- Palacios-Morales, C.A., J.P. Aguayo-Vallejo, Trujillo-Roldan, Zenit, R., M.A., Ascanio, G., Cordova-Aguilar, M.S., The flow inside shaking flasks and its implication for mycelial cultures.Chemical Engineering Science, 152, 163-171, 2016.
- Martin, R. and Zenit, R. Heat transfer resulting from the interaction of a vortex ring with a heated wall. Journal of Heat Transfer, 130, 051701, 2008.