For more information about this meeting, contact Andrew Belmonte, Tim Reluga.
|Seminar:||The Pritchard Lab Seminar|
|Speaker:||Roberto Zenit, Instituto de Investigaciones en Materiales, UNAM - Mexico|
|Turbulent flows are characterized, among many other things, by large fluctuations. This *agitated* nature of turbulence results from the instability of laminar flows, arising when inertial effects become more important that viscous ones; in other words, when the Reynolds number of the flow is large. The increased agitation is precisely what makes these flows attractive for many industrial applications, since the associated coefficients of mass and heat transfer are very high for turbulent flows. It turns out that in many two-phase flows, similar characteristics can be achieved at much smaller Reynolds numbers. For instance, when air bubbles ascend in a quiescent fluid, their motion induces velocity fluctuations in the surrounding liquid. The statistical description of these fluctuations is somehow similar to those in proper turbulent flows; hence the agitated state of bubbly flow has been called pseudo-turbulent by many researchers. There are many potential applications for high levels of agitation achieved in low Reynolds number flows, in particular to biological systems where the integrity of living entities can be compromised by high Reynolds number stresses. The understanding of how the magnitude of pseudo-turbulence scales is still rather limited. In this talk I will present experimental results and their interpretation to understand the fundamental nature of the turbulent-like fluctuations that appear in bubbly liquids.|
Room Reservation Information
|Date:||04 / 27 / 2009|
|Time:||02:30pm - 03:30pm|