1. Zhang, X., Harris, M.T., and Basaran, O.A., 1994 Measurement of dyanmic surface tension by a growing drop technique. J. Colloid Interface Sci. 168, 47-60.

2. Zhang, X. and Basaran, O.A. 1995 An experimental study of dynamics of drop formation. Phys. Fluids 7, 1184-1203.

3. Zhang, X. and Basaran, O.A. 1996 Dynamics of drop formation from a capillary in the presence of an electric field. J. Fluid Mech. 326, 239-263.

4. Zhang, X. and Basaran, O.A. 1997 Dynamic surface tension effects in impact of a drop with a solid surface. J. Colloid Interface Sci. 187, 166-178.

The goals of the research are to carry out experimental and computational studies to investigate the fundamentals of atomization, impact, rebound and wetting of drops of "real" liquids in atomization coating applications. This work is driven equally by the desire to carry out environmentally-friendly coating processes and also by that to achieve high-quality coatings. Real fluids used in real applications contain high loadings of polymer and solids and surface-active species. Therefore, fluids used in real-world applications are never simple Newtonian liquids with constant bulk and interfacial properties but instead exhibit dynamic surface tension (DST) and non-Newtonian behavior including viscolasticity. Also of interest in the research is the use of external electric and acoustic fields to control spray coating processes.

The experimental portion of the research is focused on the one hand on gaining insights into both the atomization of a liquid into droplets at a suitable nozzle and the subsequent targeting and impact of one or many drops onto various substrates and on the other hand on developing and/or improving techniques for the measurement of interfacial (e.g. DST) and bulk (e.g. extensional viscosity) rheological properties. Two visualization systems are key to studying atomization or drop formation and drop impact processes. The first of these is a very high-speed visualization system by Kodak, already in place, that is capable of recording more than 6,000 frames with a time resolution of about 0.1 milliseconds. The second of these is an ultra high-speed visualization system by Cordin, which is on order, that is capable of recording 8 frames with a time resolution of 10 nanoseconds. Also available is a Phase Doppler Anemometer (PDA) system that is capable of making drop size and (two-component) velocity measurements. The computational side of the research relies on finite element, boundary element, and volume of fluid methods to model the breakup, impact, rebound, and wetting of liquid drops.

Purdue
HomePage

General
Information

Engineering
HomePage

Computing
Network

Topic
HomePage