Fluid Mechanics and Transport Phenomena in Multiphase
Suspensions
Research Topics
Dynamics of hybrid compound drops in viscous fluids
Hybrid drops are composed of several immiscible phases. Their dynamics and deformation in viscous fluids is complex because of the existence of several interfaces. We study such systems using conformal mapping techniques and numerical methods. We are interested in macro and micro gravity environments and the effect of thermocapillarity induced by temperature or concentration fields.
Bialik-Rosenfeld, L., Lavrenteva, O. M. and Nir, A., 2007 “Thermocapillary Motion of
Hybrid Drops” Phys. Fluids (submitted).
Thermocapillary interaction of drops and bubbles
We study diffusive, convective and deformation effects on the interaction of drops and bubbles. Pattern formation and the effect on coalescence emerge. The effort is grossly directed to two avenues :
1. Spontaneous interaction due to interfacial transport.
2. Interaction induced by external gradients.
Frolovskaya, O., Nir, A. and Lavrenteva, O. M., 2006 “Thermal wake interaction of two particles
in a gravity field at low Reynolds and high Peclet numbers” Phys. Fluids 18, 072103 (17 pages).
Bialik-Rosenfeld, L., Lavrenteva, O. M. and Nir, A., 2007 “Spontaneous thermocapillary drops
interaction: the effect of a surface reaction” AIChE J. 53, 2383 – 2394.
Turbulent patterns on free interface of sheared suspensions
This project is in collaboration with Prof. Raphael Semiat. The combined effects of particle shear-induced diffusion and capillary forces lead to a turbulent flow pattern at a free surface of a sheared suspension. It is a curious phenomenon since the high the effective viscosity (particle concentration) the stronger is the observed turbulence.
Loimer, T., Nir, A. and Semiat R., 2002, "Shear-induced corrugation of free interfaces in Concentrated suspensions" J. Non-Newtonian Fluid Mech. 102, 115-134 Issue dedicated to Prof. Andreas Acrivos.
Singh, A., Semiat, R. and Nir., A., 2006, “Free-surface flow of concentrated suspensions“
Int. J. Multiphase flow 32, 755-790.
Deformation patterns of slender drops and bubbles in non-Newtonian systems
This project is in collaboration with Dr. Moshe Favelukis of Shenkar College.
Favelukis, M., Lavrenteva, O.M. and Nir, A., 2005, "Deformation and break up of a
non-Newtonian slender drop in an extensional flow" J. Non-Newtonian Fluid Mech. 125, 49-59.
Favelukis, M., Lavrenteva, O.M. and Nir, A., 2006, "Deformation and break up of a non-Newtonian
slender drop in an extensional flow: inertial effects and stability" J. Fluid Mech. 563, 133-158.
Dynamics of drops and bubbles in yield-stress fluids
Dynamics, interaction and deformation of droplets in yield-stress materials such as Bingham fluids reveal interesting and unusual phenomena. This research combines analytic and numerical models to be solved using Boundary Integral representations and the use of corroborating calculations via application of available software and codes.
Potapov, A., Spivak, R., Lavrenteva O.M. and Nir A., 2006 “Simulation of motion and
deformation of newtonian drops in Bingham fluid” I&EC Research 45 (21), 6985 - 6995.
Links
References
Bialik-Rosenfeld, L., Lavrenteva, O. M. and Nir, A., 2007 “Thermocapillary motion of hybrid drops”
Phys. Fluids (submitted).
Bialik-Rosenfeld, L., Lavrenteva, O. M. and Nir, A., 2007 “Spontaneous thermocapillary drops
interaction: the effect of a surface reaction” AIChE J. 53, 2383 – 2394.
Singh, A., Semiat, R. and Nir., A., 2006, “Free-surface flow of concentrated suspensions“
Int. J. Multiphase flow 32, 755-790.
Favelukis, M., Lavrenteva, O.M. and Nir, A., 2006, "Deformation and break up of a non-Newtonian
slender drop in an extensional flow: inertial effects and stability" J. Fluid Mech. 563, 133-158.
Potapov, A., Spivak, R., Lavrenteva O.M. and Nir A., 2006 “Simulation of motion and deformation
of newtonian drops in Bingham fluid” I&EC Research 45 (21), 6985 - 6995.
Frolovskaya, O., Nir, A. and Lavrenteva, O. M., 2006 “Thermal wake interaction of two particles
in a gravity field at low Reynolds and high Peclet numbers” Phys. Fluids 18, 072103 (17 pages).
Favelukis, M., Lavrenteva, O.M. and Nir, A., 2005, "Deformation and break up of a non-Newtonian
slender drop in an extensional flow" J. Non-Newtonian Fluid Mech. 125, 49-59.
Loimer, T., Nir, A. and Semiat R., 2002, "Shear-induced corrugation of free interfaces in Concentrated suspensions" J. Non-Newtonian Fluid Mech. 102, 115-134 Issue dedicated to Prof. Andreas Acrivos.
