Tuesday, September 4, 2012
101 Stanley Thomas Hall
Tulane University (Uptown)
Refreshments will be served
Jacek Wrobel, Tulane University, Center for Computational Science
Modeling Microscale Tipstreaming in a Microfluidic Flow Focusing Device
In order understand the mechanisms behind tipstreaming process and to gain more control of this process we model a droplet formation regime in microfluidic device. In that regime threads form periodically and the tread formation gives way to tipstreaming of micrometer-scale droplets. We propose to model the regime by the bubble in soluble surfactant solution due to an axisymmetric extensional Stokes flow along the centerline of the drop and going through a narrow opening or orifice in a vertical wall. The aperture is centered at the centerline of the bubble. The concentration of bulk soluble surfactant was found to significantly effect the mode of formation and size of the emitted droplets. By carefully controlling the surfactant concentration and other flow quantities, droplets can be created that are an order of magnitude or more smaller than the scale of both the device and droplets produced in the absence of surfactant.
Center for Computational Science, Stanley Thomas Hall 402, New Orleans, LA 70118 firstname.lastname@example.org